SR20VE conversion w/ EFR7670 low dyno numbers

[Kaisen]

Hello, is anyone running on the same setup? Just sent it in for a dyno with tuning and it's making 330 whp. I know that mainline dynos are heart breaking but its somewhat lower than what I expected. Just wanting to compare the figures with someone who is using the same setup or someone who can provide some insights. 2L SR20VE conversion, 725cc injectors, borgwarner EFR7670 twin scroll dual wastegate. Boosting at 1.6 bar. Also, from the dyno chart, the boost starts to drop towards the end, is that normal?

Attached dyno chart for reference

https://ibb.co/b28qDK

[Kingtal0n]

most 2.0L engine at 15-17psi produce about 300ft*lbs of torque on a dynojet

Not sure what that translates to for you

btw 300 ft*lbs at 7,000rpm is 400rwhp (dynojet)

Thats a stock redtop with a cam and turbo doing that

[RZRSHARP_240SX]

I run a efr7670 twin scroll on a SR22vet and I’m make 470whp on a Mustang dyno on similar boost level.

What cam are you running in the VE?

[Kaisen]

I run a efr7670 twin scroll on a SR22vet and I’m make 470whp on a Mustang dyno on similar boost level.

What cam are you running in the VE?

I'm running stock P11 cams in the VE. What a big difference between yours and mine, I was hoping to hit 380 to 400 haha :facepalm:

[RZRSHARP_240SX]

I'm running stock P11 cams in the VE. What a big difference between yours and mine, I was hoping to hit 380 to 400 haha :facepalm:

I’m using the N1 cams w/ super tech valve springs and I’m also using the stroker. I’m at 400whp at 18 psi. I was still making power around 8500rpm.

What intake manifold and throttle body?

[S14DB]

The SR16VE cams?

[Kaisen]

I’m using the N1 cams w/ super tech valve springs and I’m also using the stroker. I’m at 400whp at 18 psi. I was still making power around 8500rpm.

What intake manifold and throttle body?

I am using Mazworx Intake manifold and a Q45 throttle body.

http://zilvia.net/f/showthread.php?t=453229

I was following this thread and he's getting 450 on the wheels with stock P11 head. The turbo he is using is a GTX3076R though..

Was wondering if I should upgrade the injectors to 1000cc ones as my tuner said the 725cc is at maximum duty. Would that be a cause for the boost drop past 5k rpm?

[RalliartRsX]

The SR16VE cams?

Not the standard 16VE cams. But the huge (for turbo) overlap N1 cams.

Never understood the use of a 90mm TB. The Papadakis drift Scion makes close to 1000HP from a 2.7 liter takoma 4 cylinder and only runs a 66-70mm electronic DBW TB........

Anyways, Kaisen, its tough to determine what your issue is. Seems like you are a little sluggish getting onto to boost as well.

P11 cams should not be an issue as well (unless you have cam gears).

Have you checked the basics?? 725cc being maxed may also be your issue. 725 @ 43.5 base fuel pressure and 90% duty cycle you are sitting at 350 WHP.

[RZRSHARP_240SX]

I think the injectors will play a large part. I’m running 1000cc injectors on mine

[Kaisen]

Not the standard 16VE cams. But the huge (for turbo) overlap N1 cams.

Never understood the use of a 90mm TB. The Papadakis drift Scion makes close to 1000HP from a 2.7 liter takoma 4 cylinder and only runs a 66-70mm electronic DBW TB........

Anyways, Kaisen, its tough to determine what your issue is. Seems like you are a little sluggish getting onto to boost as well.

P11 cams should not be an issue as well (unless you have cam gears).

Have you checked the basics?? 725cc being maxed may also be your issue. 725 @ 43.5 base fuel pressure and 90% duty cycle you are sitting at 350 WHP.


Yes, that's why I have no idea where or what to check from as I'm not really familiar with all the tuning stuff, like duty cycle etc. The TB was what I have that time so I threw it on. Would you recommend getting 1000cc injectors and try again?

[Kingtal0n]

For comparison sake

couple S13 engines,
Stock redtop with a cam and turbo big enough 17.5psi~
https://s19.postimg.cc/3tlyyeurn/Karlfinal400hp6-23-11.jpg

built s13 engine 9:1 forged etc... but slightly smaller turbo (42lb/min unit)
https://s19.postimg.cc/f5ykgdixv/randidyno.jpg

[Kingtal0n]

hehe one more

heres my old car with 2 different turbos same engine
Green is 50trim @ 15psi
Blue is 50trim @ 18psi
Red is 60-1 @ ~20psi

All T3 turbine, 48ar same
https://s19.postimg.cc/j4vrz0kdv/comparison50-to-60.jpg

[Kaisen]

Doesn't make any sense right?! :facepalm:

[Kingtal0n]

your curve looks like its got a 280-290* cam and torque doesn't even peak until 8,000rpm or something. Look at it, its just going up up up. If you had hit the peak then we could say something but as it sits it looks like an enormous cammed enormous turbo engine working as intended. Those combos are legit, but they are also intended to be spun up with 100N2O progressive, 28-32psi of boost and revved out to 9k on ethanol

I'd say working as intended or the cam isn't degree'd or something like that
Oh I just noticed its two power curves. So lets do math instead-

is this the turbo?
https://www.full-race.com/store/images/full/borgwarner-efr-7670-turbo-2-content-9.jpg

at 26psi it flows 53-55lb/min
lets math the 2.0L engine
122 * 9000/3456 = 317cfm * .069 = 21.9lb/min * 2.8(40.6 absolute psi = 26psi gauge) = 61.3lb/min or 610bhp

So you can't run it to 9k but I bet 8500 is close
122 * 8500/3456 = cfm * .069 = lb/min * 2.8(40.6 absolute psi = 26psi gauge) = 58lb/min or 580bhp

Looks like an 8200rpm redline the turbo flows max capacity around 25-26psi of 55lb/min (falling off so watch the IAT)

Lets see if the engine is healthy by comparing dyno result with the same math
What do we predict at 7000 and 1.25bar of boost (32.6 absolute psi)
122 * 7000 / 3456 = 247cfm * .069 = 17lb/min * 2.25 = 38.25lb/min or 380bhp * .88 ( 12% drivetrain loss might be low :D ) = 336rwhp

dead on for 2.0L and your dyno shows 311-330hp which correlates with the 1-2% additional drivetrain losses incurred from above estimated at 12%
Notice it doesn't matter DE or VE as 2.0L is = 2.0L its what you do with that 2.0L

Can't see A/F curve or timing curve so can't tell if its tuned right. might be 50 horses hiding in tuning. Usually around 20-25% can be tuned in or out but overall results are standard.

[Kaisen]

your curve looks like its got a 280-290* cam and torque doesn't even peak until 8,000rpm or something. Look at it, its just going up up up. If you had hit the peak then we could say something but as it sits it looks like an enormous cammed enormous turbo engine working as intended. Those combos are legit, but they are also intended to be spun up with 100N2O progressive, 28-32psi of boost and revved out to 9k on ethanol

I'd say working as intended or the cam isn't degree'd or something like that
Oh I just noticed its two power curves. So lets do math instead-

is this the turbo?
https://www.full-race.com/store/images/full/borgwarner-efr-7670-turbo-2-content-9.jpg

at 26psi it flows 53-55lb/min
lets math the 2.0L engine
122 * 9000/3456 = 317cfm * .069 = 21.9lb/min * 2.8(40.6 absolute psi = 26psi gauge) = 61.3lb/min or 610bhp

So you can't run it to 9k but I bet 8500 is close
122 * 8500/3456 = cfm * .069 = lb/min * 2.8(40.6 absolute psi = 26psi gauge) = 58lb/min or 580bhp

Looks like an 8200rpm redline the turbo flows max capacity around 25-26psi of 55lb/min (falling off so watch the IAT)

Lets see if the engine is healthy by comparing dyno result with the same math
What do we predict at 7000 and 1.25bar of boost (32.6 absolute psi)
122 * 7000 / 3456 = 247cfm * .069 = 17lb/min * 2.25 = 38.25lb/min or 380bhp * .88 ( 12% drivetrain loss might be low :D ) = 336rwhp

dead on for 2.0L and your dyno shows 311-330hp which correlates with the 1-2% additional drivetrain losses incurred from above estimated at 12%
Notice it doesn't matter DE or VE as 2.0L is = 2.0L its what you do with that 2.0L

Can't see A/F curve or timing curve so can't tell if its tuned right. might be 50 horses hiding in tuning. Usually around 20-25% can be tuned in or out but overall results are standard.

I don't really know the maths behind it hahaha. Perhaps I should bring it to another tuner to take a look at it again, meanwhile I'll upgrade the injectors. The current tuner set it at 1.6 bar of boost.

How are my numbers so far apart from this following build, his is also a 2L build if Im not wrong:

http://zilvia.net/f/showthread.php?t=453229
http://zilvia.net/f/showpost.php?p=5809292&postcount=453


This person as well:

http://zilvia.net/f/showthread.php?t=532438&page=5
http://zilvia.net/f/showpost.php?p=5653995&postcount=142

[S14DB]

What is your ECU and Boost control?

[Kaisen]

What is your ECU and Boost control?

Im using Link ECU and MAC boost controller wired directly into the ECU

[rbs14kouki]

Adam's from C's garage in NZ is running a 2.2 with a 7670 internal gate . And making about twice your output . Something is not right

I would bump the injectors to minimum 1000cc . For pump gaz and even consider 2000cc if plan on running ethanol . Not to grenade your engin

[S14DB]

Im using Link ECU and MAC boost controller wired directly into the ECU

What duty cycle % do your injectors get to during the run? What are your boost control settings in the ECU?

[rbs14kouki]

Were gona need abit more info on your built to help . The cams are not a problem i have a friend making 450whp on mustang dyno with a smaller turbo then yours (pte5431)

[Kingtal0n]

this
http://i627.photobucket.com/albums/tt352/jr_ss/SR20VET%20Dyno%20Day_zps1mqlb86i.png

is more than 17psi, or it was run with an extraordinary fuel that allowed a massive increase of ignition timing. 2.0L pump gas 93 octane with 17psi make 300 ft*lbs all day. Doesn't matter what 2.0L
This is more like 21-22psi or it has E85 or something. Even with E85 i don't see an extra 70 ft*lbs happening though. lol at spark blowout at 17psi btw. I've had it happen with a .028" gap on a copper plug at... yep 23psi of boost.

s293.photobucket.com/user/BlueDragoon0/media/P1010134.jpg.html
Second one is on point, he claims 436N*M torque and 400NM is 295ft*lbs so I agree 16-17psi is perfect in the range of 300ft*lbs to be legitimate claim. As you will see majority are legit claims but every here and there someone will say 17psi when they meant 22psi. It happens.


again, I have no idea what cam/tune you have. But you can clearly investigate for yourself every legitimate 2.0L in history pretty much produces the same amount of torque at the same air pressure because the cylinder total volume can only be the same size each time it fills. Air density plays a role obviously the larger the turbo the more dense the air will be at the time, which is why we use compressor map before purchasing turbo. Also remember E85 changes things a bit. FP turbo EVOS make 550ft*lbs but also AWD and run 32-36psi of boost E85 on 2.0L try a cross examination of theirs at 17psi to see what I am saying, you want double the torque you double the density with the same cylinder volume.

[Kingtal0n]

notice the red line in the dyno overlay I posted goes above 300 ft*lbs through the middle range, that 60-1 compressor

here is the dyno video of that run hopefully it embeds
If not here is the full comparison thread with video
http://www.freshalloy.com/showthread.php/140741-Dyno-Comparison-50trim-and-60-1-HKS-vs-Brian-Crower
https://www.youtube.com/watch?v=sSylrvVIwGk

Notice where the torque exceed 300 ft*lbs boost exceeds the usual 17psi range

some evo dynos for comparison
https://www.socalevo.net/threads/135446-Dyno-Database-Project-Evo-9-Stock-amp-FP-Green-Turbos
22psi AWD 2.0L
https://www.socalevo.net/gallery/albums/userpics/10300/normal_Evo9%20DaveS%203-07%20357.jpg

different car 2.0L 21psi AWD
https://www.socalevo.net/gallery/albums/userpics/10300/normal_Evo9%20ThomasG%2012-06%20323.jpg

different car 2.0L 29psi AWD FP"red" E85
https://www.evolutionm.net/forums/attachment.php?attachmentid=310216&d=1501791993
https://www.evolutionm.net/forums/evo-dyno-tuning-results/380134-fp-red-dyno-results-thread-3.html

[Kaisen]

What duty cycle % do your injectors get to during the run? What are your boost control settings in the ECU?

My tuner says the injectors are close to 100%, so I think they are getting maxed out. As for boost control settings, I have no idea on that as I know nuts about tuning.

Were gona need abit more info on your built to help . The cams are not a problem i have a friend making 450whp on mustang dyno with a smaller turbo then yours (pte5431)

Build list:

P11 head with stock cams
supertech valvetrain set 93lb
Naprec Valve Guides
CP VE Pistons Bore x CR: 87.0 x 9.0:1
Spool Import Conrods
Cosworth Main Bearings
Cosworth Conrod Bearings
Tomei 1.0mm Headgasket
Mazworx Intake Manifold with fuel rail
Injector Dynamic 725CC Injectors
Walbro 255 Fuel Pump
Works Engineering Fuel Regulator
Works Engineering Q45 Throttle Body
HKS Intercooler
Earls Oil Cooler
Borgwarner EFR7670 twinscroll dual external wastegate
Full race top mount exhaust manifold
tial 38mm wastegates x2 with 1.3 bar springs
boost set at 1.6 bar, which is around 23 psi

[Kaisen]

notice the red line in the dyno overlay I posted goes above 300 ft*lbs through the middle range, that 60-1 compressor

here is the dyno video of that run hopefully it embeds
If not here is the full comparison thread with video
http://www.freshalloy.com/showthread.php/140741-Dyno-Comparison-50trim-and-60-1-HKS-vs-Brian-Crower
https://www.youtube.com/watch?v=sSylrvVIwGk

Notice where the torque exceed 300 ft*lbs boost exceeds the usual 17psi range

some evo dynos for comparison
https://www.socalevo.net/threads/135446-Dyno-Database-Project-Evo-9-Stock-amp-FP-Green-Turbos
22psi AWD 2.0L


different car 2.0L 21psi AWD


different car 2.0L 29psi AWD FP"red" E85

https://www.evolutionm.net/forums/evo-dyno-tuning-results/380134-fp-red-dyno-results-thread-3.html

So I guess that's about it then sigh. My tuner set the boost at 1.6 bar, which is about 23 psi. But it drops off to 20psi afterwards

[RalliartRsX]

So a few things
1) 725cc injectors @ 43.5 base pressure and 90% duty cycle equates to just about 350WHP. The injectors have room (not much, but they are not maxed out), especially if you bump up fuel pressure to 4 bar (however, you run into issue with max differential fuel pressure across the injectors)

2) I made a little over 300 WHP on a B1 frame 6758 on a (stock unopened) S13 head with S4 cams. Torque was 250 ftlbs from ~3400 all the way to 7250 redline. So no where near the flow of a VE (especially "IF" you went up a size on the exhaust valves)

3) @ 1.6 bar on a 7670 is well into the 400 WHP on a VE head.

4) Graph is missing AFR data.

I am not convinced fuel is your issue (atleast not just yet)

If you are past 100% duty cycle, your car would be leaning out severely as RPMs and boost goes to 1.6BAR. The data stream would show this instantly. If pump pressure is stable and you keep adding fuel and no changes, then that's a quick indication

What does the AFR graph look like plotted against fuel pressure?? How about the timing map?? Injector pulsewidth map??

For us to look at a dyno graph and determine your issue is going to prove extremely difficult. As it stands right now, HP is still climbing. Torque falls off with boost. So the setup (on the surface) seems to be working as any ICE with a turbine/compressor slapped on should be acting. However, full boost by 5300 RPM is laggy for a 7670, especially considering you are on a twin scroll setup on a VE head. What AR is the turbine??

You have the full data stream at your finger tips. Go through it with your tuner.

[Kaisen]

So a few things
1) 725cc injectors @ 43.5 base pressure and 90% duty cycle equates to just about 350WHP. The injectors have room (not much, but they are not maxed out), especially if you bump up fuel pressure to 4 bar (however, you run into issue with max differential fuel pressure across the injectors)

2) I made a little over 300 WHP on a B1 frame 6758 on a (stock unopened) S13 head with S4 cams. Torque was 250 ftlbs from ~3400 all the way to 7250 redline. So no where near the flow of a VE (especially "IF" you went up a size on the exhaust valves)

3) @ 1.6 bar on a 7670 is well into the 400 WHP on a VE head.

4) Graph is missing AFR data.

I am not convinced fuel is your issue (atleast not just yet)

If you are past 100% duty cycle, your car would be leaning out severely as RPMs and boost goes to 1.6BAR. The data stream would show this instantly. If pump pressure is stable and you keep adding fuel and no changes, then that's a quick indication

What does the AFR graph look like plotted against fuel pressure?? How about the timing map?? Injector pulsewidth map??

For us to look at a dyno graph and determine your issue is going to prove extremely difficult. As it stands right now, HP is still climbing. Torque falls off with boost. So the setup (on the surface) seems to be working as any ICE with a turbine/compressor slapped on should be acting. However, full boost by 5300 RPM is laggy for a 7670, especially considering you are on a twin scroll setup on a VE head. What AR is the turbine??

You have the full data stream at your finger tips. Go through it with your tuner.

Will do so, thank you very much for your input. The AR is 1.05. Perhaps I'll try another tuner and see if there's any difference in the results

[Kingtal0n]

just take more control of the situation.

You have not posted any significant details as others are mentioning. we are in the dark here about what the combo should be doing. All I can do is take generic maths, which are at best 80-90% accurate and draw generic conclusions about the displacement and the RPM.

First thing that springs to my mind is this:
The whole point of using VE head is the extended RPM capability with no rocker to throw. I.e. 7,100rpm-9,500rpm ranges. Any regular 2.0L from any manufacturer can do 6k 7k but it takes a serious engine to flow well at 8k 9k. Look at all those evo graphs, how torque just falls right off. That is how the majority of 2.0L engines are, including sr20det from the factory with stock cams. You can change the cam in the sr20det and extend that curve to 7k maybe even 7,500 to 8,000, but where the DET head falls short as-is the VE head is still highly capable past that point. This is the reason to use the VE conversion; everything below that point (roughly 7k to 8k rpm) is going to be more or less identical to an SR20det head with the same cam because the det head flows just fine in that range.

[RalliartRsX]

First thing that springs to my mind is this:
The whole point of using VE head is the extended RPM capability with no rocker to throw. I.e. 7,100rpm-9,500rpm ranges. Any regular 2.0L from any manufacturer can do 6k 7k but it takes a serious engine to flow well at 8k 9k. Look at all those evo graphs, how torque just falls right off. That is how the majority of 2.0L engines are, including sr20det from the factory with stock cams. You can change the cam in the sr20det and extend that curve to 7k maybe even 7,500 to 8,000, but where the DET head falls short as-is the VE head is still highly capable past that point. This is the reason to use the VE conversion; everything below that point (roughly 7k to 8k rpm) is going to be more or less identical to an SR20det head with the same cam because the det head flows just fine in that range.

You are only partially correct in your statement. The reason the VE head can extend the operating rage is because the head is capable of supporting it. In addition, the head simply outflows the a DE at every single point in the RPM range.

I am not convinced you are aware of just how much more the VE flows over even a heavily massaged DE head with huge cams, which kills power below 6K. You literally do not have enough port material to remove to gain the amount of volume a VE head can flow, hence why you cannot machine a DE head (I have only seen very limited scenarios few folks have gotten close) to the level of a VE head. The VE head casting is entirely different than that of the DE head let alone everything else (ports angles themselves are different as the VE ports have been moved up a few mm to allow better entry angle).

Essentially, the VE head with outspool and out power a DE head at just about every single RPM. The following statement is unequivocally false

"everything below that point (roughly 7k to 8k rpm) is going to be more or less identical to an SR20det head with the same cam because the det head flows just fine in that range."

In addition, cam profiles are entirely different VE to DE, so there is simply no way to make a direct comparison. Yeah, you can compare lift and duration, but due to the VE head design, you cannot make a direct comparison.

Link to flow numbers of a stock VE head with P11 cams. P12 cams are better for turbo to note.

http://forums.nicoclub.com/sr20ve-head-flow-vs-sr20det-head-flow-t558190.html

Power is heavily dependent on head flow, not just displacement as you continue to harp on about. That's why it takes the 1stGen 4G63s 20-30 psi of boost to make what a K20 will make at (literally) half that boost with everything else being equal. The 1st Gen 4G63 had some horribly flowing heads.

[Yellow4g63]

I'd check the mechanical cam timing on the motor. If you run a old oem pulley it could be slipping and giving you the wrong timing marks too. Good luck.

[Kingtal0n]

You are only partially correct in your statement. The reason the VE head can extend the operating rage is because the head is capable of supporting it. In addition, the head simply outflows the a DE at every single point in the RPM range.

I am not convinced you are aware of just how much more the VE flows over even a heavily massaged DE head with huge cams, which kills power below 6K.


Power is heavily dependent on head flow, not just displacement as you continue to harp on about. That's why it takes the 1stGen 4G63s 20-30 psi of boost to make what a K20 will make at (literally) half that boost with everything else being equal. The 1st Gen 4G63 had some horribly flowing heads.


An engine can only fill its cylinder to the max. A 2.0L has the same cylinder volume no matter what head is on it. That means peak pressure maximum is always the same, which means peak possible torque is always the same.


And you can't make more power without more torque at the same rpm.

Furthermore, the better the flow at high flow rates, typically the lower the flow at low flow rates due to poor port velocity. So having heads and intakes and cams that flow a lot at high rpm will usually hurt torque at low flow rates, hurt cylinder fill.

Basically to re-state, the cylinder can only fill 100%, it doesn't matter how much the head can flow. Torque is the relationship to cylinder fill, NOT power. Power is determined by overall flow per time, or mass/time flow rate. torque can only go as high as 100% cylinder fill.

Example
sr20det engine at 4000rpm making 300ft*lbs of torque with the stock head (max flow of X), has 99% cylinder fill
Now lets put on the VE head
SR20VET engine at 4000rpm making 300ft*lbs of torque with the VE head(max flow of 2X), has 99% cylinder fill (same)

The engines both make the same torque at the same RPM when cylinder fill is maximum for both, even though one head flows double.
Now, some torque can be gained or lost any number of small ways. Compression ratio. Head design/port shapes/swirl character. Injector timing. Exhaust gas velocity/pressure. Ignition timing, fuel quality, &c So I do believe there is some room to 'gain torque' given the identical displacement; however it is difficult for me to say how much 'different' the VE engine somebody random assembles is to the next thing. Which is why I give general maths and ideas.

[Kingtal0n]

Another example from other thread

https://s19.postimg.cc/6f75whk03/allday.jpg

Pretty easy to see torque scale with boost. Just focus on torque because that is cylinder fill, which can only be 100% max. The engine clearly makes a max VE approaching 5500rpm where boost stops rising, max VE = max cylinder fill. Cylinder fill likely stays up after 7k because amazing VE head, but the turbo runs out of flow rate so the air loses density and power levels off. At that point is when we start to consider power and max flow rate and all of that because its the turbo's job to provide the dense air at high flow rates, and if can't keep up with the engines ability to flow then the only thing you can do is install larger turbo if you wanted more power. But max torque isn't going to get better with larger turbos or more head flow than this because adiabatic efficiency of compressors is pretty much standard as long as you are within the specific range the turbo prefers, and head flow rate isn't going to increase cylinder fill beyond 100%.

[Kingtal0n]

EVO makes 550ft*lbs, 32-36psi, E85, 2.0L
https://s19.postimg.cc/w6x2zr8qb/FPEVO9.jpg

The guy who claims 370ft*lbs of torque at 17psi is also basically saying that an extra 18psi of boost, 0.2L of displacement and E85 is only worth 155ft*lbs of torque
When we know E85 plus 0.2L is worth around 50-70ft*lbs in and of itself, is like saying an extra 18psi is only good for 80-90~ ft*lbs of torque (non logical)

I looked through the srve thread and there does not seem to be anyone running lower boost pressures to compare with.
However it is extremely easy to find N/A Setups which clearly show 100% cylinder fill at 0psi of boost
sr20ve
http://i14.photobucket.com/albums/a318/turboser91/scan0002.jpg
sr20ve
http://i21.photobucket.com/albums/b296/gt20ir/Dyno%20sheets/scan0003-1.jpg
sr20ve
https://www.sr20forum.com/gallery/data/500/medium/happynole_VE_SE-R_NX_dyno_runs.jpg
sr20ve
http://i17.photobucket.com/albums/b54/SER96VSPEC/SE-R/aftertune062710.jpg

Notice no matter what they all approach 150 ft*lbs at 0psi, approaching 100% cylinder fill with typical gasoline. In calculus, we would call this a"limit".
You can approach the limit, and be under the limit.
To use this math to your advantage simple multiply in the pressure ratio to find new torque, taking into account any friction, adiabatic efficiency, fuel quality
for example:
If I wanted to know how much torque at 15psi of boost I could say
15/14.5 = 1.034 + 1atm = 2.034 total pressure ratio
150*2.034 = 305ft*lbs
now, lets account for losses such as friction and adiabatic efficiency, say we lost 5% due to non component head losses (pump head loss from airpath friction, intercoolers, etc) and another 1% due to slight temp rise persisting after a non-perfect ambient temperature intercooling and 4% from other sources we can't imagine all of them, exhaust gas pressure pumping loss or something. Realize that there will be some additional losses. It doesn't matter exactly what they are, only that we expect some form of degraded output, it might even be a different percentage at each individual RPM. You can spend alot of time and effort lowering that percentage and improving efficiency, and even the atmosphere from day to day will influence so it isn't always the same number day to day either. Lets figure 10% for our rough calculations next though to keep it simple.
305 * .90 = 274ft*lbs of torque

Lets do it for 18psi now
18/14.5 = 1.24 + 1atm = 2.24
150*2.24 = 336ft*lbs
minus 10% for losses as above
336 * .9 = 302ft*lbs

Remember we are already working with torque at the tires so no need to compute drivetrain losses. Just keep in mind losses maybe higher in RWD platforms by a couple percentage.

If we removed the intercooler completely our adiabatic would be only something like 70%, it could be 20% less torque at the same boost when IAT would be much higher going into the engine (it comes out of a compressor 250*F or more at the pressures we are talking) and therefore air density would be lower. This why N/A torque comparisons are so powerful; they give you the torque production limit of a given displacement engine when the intercooler is 100% efficient (no boost, no intercooler) but there may not always be minimal air pathway resistance/friction and different engines have different frictions (some are lighter like Honda). There is typically some air heating as the air moves through the engine bay (so not quite ambient temp) and it could indeed be cooler coming out of an intercooler at ambient temp. Also remember the power lost on the intake stroke is used to draw air into the engine is heavily compensated for in a turbo application because of the kinetic energy of the incoming air stream towards the engine.

[Kingtal0n]

And just for good measure
http://i24.photobucket.com/albums/c9/240sx_god/MikeDyno-June182012.jpg

Guess how much boost
http://nissanroadracing.com/forum/engine/ve-vvl-conversion/4043-sr20vet-dyno-e-85-gt2868
breakdown
https://s19.postimg.cc/olynhvxwz/torqueoscilation.jpg

[jr_ss]

I don't really know the maths behind it hahaha. Perhaps I should bring it to another tuner to take a look at it again, meanwhile I'll upgrade the injectors. The current tuner set it at 1.6 bar of boost.

How are my numbers so far apart from this following build, his is also a 2L build if Im not wrong:

http://zilvia.net/f/showthread.php?t=453229
http://zilvia.net/f/showpost.php?p=5809292&postcount=453


This person as well:

http://zilvia.net/f/showthread.php?t=532438&page=5
http://zilvia.net/f/showpost.php?p=5653995&postcount=142

@Kaisen, did you ever resolve your issues?

[Kaisen]

@Kaisen, did you ever resolve your issues?

Hello! Kinda just accepted that the dyno is just a heartbreaker hahaha. Afterall it's a tuning tool and the car drives just fine and pulls hard. I have a friend who's driving an Evo X with some modifications and he's doing 350hp on the same dyno but on another dyno it reads 500. I'll probaby get a meth kit and cams and boost it till 2bar just to see how far I can push it.

Any updates on your car? Your thread is by far my favourite VE build!

[jr_ss]

Hello! Kinda just accepted that the dyno is just a heartbreaker hahaha. Afterall it's a tuning tool and the car drives just fine and pulls hard. I have a friend who's driving an Evo X with some modifications and he's doing 350hp on the same dyno but on another dyno it reads 500. I'll probaby get a meth kit and cams and boost it till 2bar just to see how far I can push it.

Any updates on your car? Your thread is by far my favourite VE build!

No updates other than the car being reunited with me after two years. I’ll start tinkering with it again, time allowing. I have some upgrades planned for it and possibly a sleeved Mazworx block too. MORE POWA!

[Kaisen]

No updates other than the car being reunited with me after two years. I’ll start tinkering with it again, time allowing. I have some upgrades planned for it and possibly a sleeved Mazworx block too. MORE POWA!

Do update if there's any! Always a joy to read your build!

[jr_ss]

this
http://i627.photobucket.com/albums/tt352/jr_ss/SR20VET%20Dyno%20Day_zps1mqlb86i.png

is more than 17psi, or it was run with an extraordinary fuel that allowed a massive increase of ignition timing. 2.0L pump gas 93 octane with 17psi make 300 ft*lbs all day. Doesn't matter what 2.0L
This is more like 21-22psi or it has E85 or something. Even with E85 i don't see an extra 70 ft*lbs happening though. lol at spark blowout at 17psi btw. I've had it happen with a .028" gap on a copper plug at... yep 23psi of boost.

again, I have no idea what cam/tune you have. But you can clearly investigate for yourself every legitimate 2.0L in history pretty much produces the same amount of torque at the same air pressure because the cylinder total volume can only be the same size each time it fills. Air density plays a role obviously the larger the turbo the more dense the air will be at the time, which is why we use compressor map before purchasing turbo. Also remember E85 changes things a bit. FP turbo EVOS make 550ft*lbs but also AWD and run 32-36psi of boost E85 on 2.0L try a cross examination of theirs at 17psi to see what I am saying, you want double the torque you double the density with the same cylinder volume.

That is my dynograph and it was between 19-20psi on 93oct. Timing was not extreme.

[Kingtal0n]

That is my dynograph and it was between 19-20psi on 93oct. Timing was not extreme.

Where is the datalog showing exact psi

Our eyes can't tell the difference between 21 and 23 on a typical gauge at the exact instant the engine hits peak torque on a dyno
Also keep in mind that most gauges vary 1-3psi , so unless you have a gauge and a datalog, or two gauge or two datalogs, you don't know what kind of error is in the reading. And there is always error term.
And finally the fact that pressure is highest near the compressor and lowest near the cylinder. If you saw 21psi at the intake through a properly sized intercooler that could very well be 26psi at the compressor. So not only is there error in the gauge, there is variance according the measurement location.



From looks of the graph I think it peaks 22 to 25psi and falls off to 20psi by redline

your original quote was 17psi though iirc and it really fucked this guy up thinking hes going to get 350ft*lbs at 17psi is a joke from any 2.0L
With a small turbine It takes 25-28psi to get that kind of torque out of a typical rwd sr20.


so first you say 17 and now it became 20, suddenly. And I bet its really 23.5 falling to 20 or something. Just be careful with ur numbers. Its very common or typical for people to make several passes, raising the boost gradually to the point where they no longer even know what the boost curve looks like or how much boost they are running. Even I am guilty of doing that while frazzled on a dyno session with my own vehicle. But when you are finished with all that, looking at the graph, don't go online and make up a boost number just because you don't have a recording of what it really was, that guess will get people's feeling hurt when they copy your setup and it only makes a fraction. Better just to say you aren't sure than use 17psi as a go-to guess.

[RalliartRsX]

lol at the fact that you think jr is running analog gauges. What is this, 1926??

He is on a Haltech with proper data acquisition so I am pretty sure the numbers are accurate.

I am going to harp; the VE allows one to run very low boost numbers to achieve staggering results on pump......akin to the Honda boys. The head flow, it's ability to resist knock (which is all in the head design) and the different coolant jackets to the standard VE head, all contribute to a heat that is much less knock prone than any DE head and allows you to get away with alot on pump.

King, please lay off the blanket statements.....

[Kingtal0n]

lol at the fact that you think jr is running analog gauges. What is this, 1926??

He is on a Haltech with proper data acquisition so I am pretty sure the numbers are accurate.

I am going to harp; the VE allows one to run very low boost numbers to achieve staggering results on pump......akin to the Honda boys. The head flow, it's ability to resist knock (which is all in the head design) and the different coolant jackets to the standard VE head, all contribute to a heat that is much less knock prone than any DE head and allows you to get away with alot on pump.

King, please lay off the blanket statements.....


We had this discussion already.
There is nothing you can do to the head of a 2L engine to make it produce more torque other than raise compression ratio.
I can make that blanket statement because it is true.

That is a fact across all platforms, all 2L engine in the world must abide by physics. 1982 - 2020 it hasn't changed much. DI improved things a little but we aren't going there.

Boost adds roughly 10ft*lbs per psi (gasoline; w/ ambient Intake air temp), regardless of what the head flows or what kind of 2L engine we are talking about, near peak torque/BSFC.


The fact he reported 17, and now suddenly 20, is highly suspect of 'guessing' and no actual data logs or reports to go from. And even then it is impossible to say whether the sensor is accurately calibrated without a second sensor. Or where the pressure data is being taken from, compared to other locations.

[jr_ss]

We had this discussion already.
There is nothing you can do to the head of a 2L engine to make it produce more torque other than raise compression ratio.
I can make that blanket statement because it is true.

That is a fact across all platforms, all 2L engine in the world must abide by physics. 1982 - 2020 it hasn't changed much. DI improved things a little but we aren't going there.

Boost adds roughly 10ft*lbs per psi (gasoline; w/ ambient Intake air temp), regardless of what the head flows or what kind of 2L engine we are talking about, near peak torque/BSFC.


The fact he reported 17, and now suddenly 20, is highly suspect of 'guessing' and no actual data logs or reports to go from. And even then it is impossible to say whether the sensor is accurately calibrated without a second sensor. Or where the pressure data is being taken from, compared to other locations.

Dude you need to lay off the pipe man. No one reported 17. You manifested a number and rolled with it. That is MY dynograph and the car is setup to run 19-20psi. Sure, there maybe an initial boost spike when the turbo lights off, but what car or turbo setup doesn?t see a slight spike(1-2psi) until the solenoid catches it. Hell even your internal gates spike. The Haltech controls boost very well and maintained 19-20 throughout the pull, without spikes. It?s on 44mm gate as well.

My boost gauges (Haltech and Defi) tee off the same vac line and are within 1psi of each other, in-fact, my Defi reads slightly higher than the computer. It doesn?t matter what pressure comes out of my turbo, what matters is what is being ingested by the motor. All that data provides is how efficient your intercooler is. There is and will always be a pressure drop across them. Your argument is invalid here.

You can sit here and throw all your mathematical figures at it and still come to the same conclusion, you?re wrong. If you have no experience with a VE head, perhaps you should get some. At the end of the day, I?m not going to post a data log for you, to legitimize myself, for your satisfaction. You can take my word for it or don?t. Personally, I don?t care what you do.

[Kingtal0n]

never said it was impossible just to be careful with numbers. I thought the thread op said your graph was at 17psi thats where I got it from.

For an sr20 engine to make an extra 50-70 ft*lbs of torque (360 instead of 300 at 19psi) there are many things you could or would have to do.
Working backwards that is like a 4L engine making 5.3L engine torque (360ft*lbs). It doesn't add up. Something is wrong, where did the extra 1.3L come from?
You can put aftermarket heads, cam, intake, exhaust, all the mods you want and it will never make more torque than the same 100% peak because you can't go over 100%.

Maybe you bored and stroked the engine to 2.4L and just forgot. Or had a 50 shot of nitrous on it.

Honda makes the most efficient engines on the planet, lets see what their 2L does at 19psi...
With E85
https://www.maperformance.com/blogs/maperformance-blog/77012035-honda-s2000-turbo-kit-specs-boosted-s2k-on-our-dyno
https://cdn.shopify.com/s/files/1/0890/6136/files/blog_s2k-dyno-graph-e1398453294455.jpg?2800034091631425998

wow look at the Honda go
This is 1.8L AND E85 , you can clearly see the resemblance to all the others (torque)
https://honda-tech.com/forums/forced-induction-16/b18c-50trim-18-14psi-e85-dyno-tune-2820252/
https://i672.photobucket.com/albums/vv89/tdcweb/eBlogger/JonathanTurboCivic.jpg
Its missing .2L so add 10% torque to what you see to compare with 2L

I'll keep looking though

heres 2.4L KA24DET
13psi of boost
http://www.ka-t.org/forums/viewtopic.php?t=45339
http://i949.photobucket.com/albums/ad339/bmitchell_ga/240_STDdyno.jpg

Intersting. Creeping on 320ft*lbs with .4 extra liters but 6psi less boost.
Lets work backwards to see if it makes sense with what we already know
Go from 2.4L to 2L so subtract 20% torque: (320 * .8) = 256ft*lbs,
now lets add the boost: for every 1psi we add roughly 10ft*lbs so lets count it out,
13 -> 19psi = 6 psi so +60ft*lbs to 256ft*lbs = 310ft*lbs of torque from 19psi at 2L !! Imagine that

Isn't it funny how no matter what engine we look at from what car, around the world

[jr_ss]

never said it was impossible just to be careful with numbers. I thought the thread op said your graph was at 17psi thats where I got it from.

For an sr20 engine to make an extra 50-70 ft*lbs of torque (360 instead of 300 at 19psi) there are many things you could or would have to do.
Working backwards that is like a 4L engine making 5.3L engine torque (360ft*lbs). It doesn't add up. Something is wrong, where did the extra 1.3L come from?
You can put aftermarket heads, cam, intake, exhaust, all the mods you want and it will never make more torque than the same 100% peak because you can't go over 100%.

Maybe you bored and stroked the engine to 2.4L and just forgot. Or had a 50 shot of nitrous on it.

I can tell you though, I've seen lots of cars run on the dyno here. hundreds, thousands, idk. And I see them raising that boost, 20, 22, 25, 28. and then go on the forums and say it was 18psi.
Happens every day.

Nope, still a 2L, even with 86.5mm pistons.

I hear what you?re saying, but I have nothing to gain by lying about what my car made/makes. Oh, this was on P11 cams as well, the worst cams for the VET setup. Remember, VE on this motor is far different than the DET. Have you seen what a factory VE head flows without modification? If I recall correctly, my intake CFMs were 273 and the exhaust was 196.

[Kingtal0n]

2.4L at 18psi:
http://www.ka-t.org/forums/viewtopic.php?t=38282
http://i259.photobucket.com/albums/hh291/rn240sx/Dyno11-1-08.jpg

So your 2L makes 2.4L torque? Where did the 0.4L come from? magic?

cams, exhaust, intake, makes no difference. Displacement is, there is no replacement. It doesn't match what is typical, is all

2L at 18psi again, volkswagon this time
https://www.getunitronic.com/ecu-tuning/Volkswagen-Tiguan-20L-TSI-2011-2012-stage1plus
https://www.getunitronic.com/imgs/dyno/big/Unitronic-Stage1plus-20TSI-Gen2-1.jpg

Oh look 325ft*lbs and its not even a dynojet.
Think about that for a minute.
They clearly fudged the numbers up a little to sell their product, and its higher than any other 2L i've ever seen because its NOT a dynojet and was fucked with, and STILL its 30ft*lbs less than what you are suggesting a 2L will make!

Mitsubishi, gasoline, 2L
https://www.evolutionm.net/forums/evo-dyno-tuning-results/526293-spec-ops-tab-fab-hta3586-93-octane.html
https://i408.photobucket.com/albums/pp168/ducatidd/HTADyno.jpg
355ft*lbs of torque... at 27psi of boost!


ur telling me you make what a 2.4L engine makes, that sr20VE makes what a 4g64 makes at 27psi, with just 19psi... it makes the 4g63 engine look like garbage! When we all know 4g63 is king. Or so I heard
Can it be that good? to beat every other engine ever made? Realistically I hope so because I will use it immediately. Can anybody find more graphs?

[jr_ss]

So I guess these guys are lying about their 36x ftlbs of torque too. Top one is Almost the exact same setup and head. The bottom is my components before I owned them. Spend some time in the VE thread too, educate yourself. Math is math when your formulas are right...

https://zilvia.net/f/showpost.php?p=5568657&postcount=46

http://i295.photobucket.com/albums/mm158/CoheedJV/JeremyHigh.jpg
https://i627.photobucket.com/albums/tt352/jr_ss/image_zps96c2d27e.jpg

[Kingtal0n]

can you please link the examples so I can find them, dynojets are all the rage

[jr_ss]

can you please link the examples so I can find them, dynojets are all the rage

This is old data. These motors/setups have become far more prevalent in the last 10yrs. Here is the link to the post for the top Dyno. You can search to find his original post. The second dynograph is from 2009-10 when the VVL setup was just becoming available. I don?t have a post for it. Again, this is old data.

https://www.sr20-forum.com/forced-induction-mechanical/!68881-n1-or-stock-ve-cams-for-my-3071r-setup.html?post_id=952948#post!952948

[Kingtal0n]

This is old data. These motors/setups have become far more prevalent in the last 10yrs. Here is the link to the post for the top Dyno. You can search to find his original post. The second dynograph is from 2009-10 when the VVL setup was just becoming available. I don?t have a post for it. Again, this is old data.

https://www.sr20-forum.com/forced-induction-mechanical/!68881-n1-or-stock-ve-cams-for-my-3071r-setup.html?post_id=952948#post!952948


Thank you, lets delve shall we

first this graph was created at 11psi of boost, according to the owner
http://i295.photobucket.com/albums/mm158/CoheedJV/JeremyLow.jpg

Lets see if it follows the 10ft*lbs per psi rule:
take 260ft*lbs and remove 11*10 = 150ft*lbs at 0psi,
this is what we expect from the 8.5:1 gasoline engine N/A platform with 0psi of boost.

So far so good.

Before moving on let us acquire a direct turbo comparison so we can effectively determine efficiency (since precision does not release compressor maps)

Here is a random 2.2L Honda (very efficient engine?) with high compression (11:1) using 14psi of boost on that turbo
https://www.s2ki.com/forums/s2000-forced-induction-142/updated-power-chart-909059/page25/#post24603727
WTQ: 315RWTQ is claimed

Lets use two of them because idk what dyno the first one has
https://www.s2ki.com/forums/s2000-forced-induction-142/updated-power-chart-909059/page23/#post24272158
Motor: F22c
Compression Ratio: 11.0:1
Specs: Bone Stock
Injectors & cc: Injector Dynamics 1000cc
Fuel Pump: Walbro 450
EMS: Hondata Kpro V4
Fuel: 93 octane, no meth
PSI: 15 PSI
WHP: 521WHP
WTQ: 360WTQ
Dyno: Dynapack

So same engine same compression but 45ft*lbs extra using dynapack dyno.

both 93 octane so thats good. 2.2L engines, 6262 turbo.

pull 10% from those due to the extra .2L of displacement and we should neglect compression for now, but remember it is higher
we get 315 * .90 = 280ft*lbs for the first and
360 * .90 = 320ft*lbs for the second (dynapack dyno)
In theory with 2L that is what they would have made at 15psi of boost w/ 11:1 compression

Does that fit 10ft*lbs/1psi ?
Lets see, 280 - 15psi = 280 - 150ft*lbs = 130ft*lbs rwtq
320 - 150 = 170ft*lbs rwtq

In the first case, unknown dyno, I would say it looks a little low. The 2L should have given 150ft*lbs so I believe the engine is stuffed (not optimized for performance). Which the owner clearly says "stock engine parts" so this fits. Plus maybe it was a mustang dyno or something like that which reads lower than dynojet. The numbers don't need to be exact; they just need to fit our solution curve that all engines fit.

next 170ft*lbs seems a bit high, but its on a dynapack which might read high by 20ft*lbs this time around. Or the dyno might read low and we are just seeing what 11:1 on boost can do.
Either way, they both come very close to the rule of thumb of 1psi per 10ft*lbs of torque.
We expect a bit more torque per psi on high compression engines.
We do NOT expect more torque for any other reason. Either psi of boost, or compression ratio, those are the factors here. The VE cannot be improved above 100%; it can only go DOWN. That is why low numbers are 'fine' but high numbers are 'impossible'. Every engine must fit this rule of thumb.


So now lets look at the 6262 turbo on 2L example with "19psi"
http://i295.photobucket.com/albums/mm158/CoheedJV/JeremyHigh.jpg

That exact same engine made 260tq with 11psi so if we extrapolate:
350 - 260 = 90 = 9psi required extra
11 + 9 = 22psi of boost required to reach 350, so lets say 23~psi of boost for 360ft*lbs

Looking closer, we see that there is a power dip in the RED curve which correlates to this boost number:
The power onslaught was so severe, boost went to 24psi momentarily before dropping back to 19psi

So here is what I see. The boost comes on to 24psi and it makes 350-360ft*lbs of torque. Which makes sense.
Then for the rest of the run, it seems like the gauge is inaccurate, or the owner wasn't still paying attention, or the owner is making the assumption that it was 19psi, or the owner wasn't sure. Or something along those lines. My gauge is cheap and it does the same thing in the car, but the datalog shows differently, so we dont know the actual boost without some kind of log and a standard.

Without the data to compare, we have no way of knowing. I do know one thing though, there is alot of mystery surrounding those numbers, and if what the owner says is true "24psi" is the ticket to making 350-360ft*lbs on a 2L engine, definitely fits our 10ft*lbs/psi rule, and definitely shows up on that graph.

Another thing to consider is that the engine in that run used a JWT computer, which uses obnoxiously high timing values. That is why the graph is so spiky/wavy even with smoothing=5.
Normally, a graph with proper timing will be smooth, especially with such a small engine and good tight, lightweight parts tuned well is smooth.
but that graph is absolutely all over the place. It goes up, down, a LOT more than we can see, it is 'saved' by smoothing=ALOT.
Well, those spikes cause erroneous torque and power readings. The dyno takes any 'peak' as it's peak number. This is an easy way to generate a falsely high number from any dyno by accident.

So with the smoothing at 5, we still see crazy spikes, that is going to have an impact on the numbers throughout the run, because the engine was pushing harder sometimes and other times struggling for a moment, then pushing again hard, the cylinder pressure was all over the place. So this is not a good representation of torque output from an engine, we should not use this graph (or any dynojet at smoothing=5) for our analysis. However I understand the fundamental lack of sr20VE graphs (which is why I keep including random engines to make our "pool" of dyno graphs useful) so we are making do with whatever we can get.

So kick that around for me and look back at what 2.2L does and play with the math a little bit to see for yourself.
lets take the 2.2L at 15psi that made 320 @ 2.0L and try again with 11:1 compression (highest torque possible at 2L with 6262 turbo)
here goes
320 @ 15psi + an extra 4psi = 320 + 40ft*lbs = 360ft*lbs of torque at 19psi with 11:1 compression at 2L

See what I am getting at here, there is no very little evidence that a 2L engine with 8.5:1 compression made by nissan can produce 360 ft*lbs at 19 psi when it takes engines like a Honda with 11:1 compression and super light drivetrain to hit that region of torque. And even then it is so rare, most of them are 2.2 or 2.4L.

I am all for fudge factors, but not convinced so far. Will need to see a few more dynojets of VE engines before I am convinced, thats all. Maybe the truth is out there.

[Kingtal0n]

This is what the dynojet is telling me about 2L on gasoline

https://i.postimg.cc/bJDD4mrz/24psiokay.jpg

Some boost controller sinusoidal activity is typical when the state-space type of boost controllers are improperly configured to respond fast enough.

So it is very easy to see what is happening. The boost rockets to some value, the controller over compensates, and it falls off, then the controller re-compensates back to the original value, over shoots again slightly, overcompensates, back and forth a couple times until it settles out near the original starting value but without overshoot and over compensation.

This is a very typical control system behavior. And since we know engine torque follows boost pressure when VE is a flat number, which is clear and easy to tell from the flat torque curve, we must conclude that whatever the initial boost pressure number is (24psi) is the same across the board, because torque is a flat line there which tells us the engine isn't losing efficiency until after 8,000rpm which is consistent with what we know about the SR20VE head.

[jr_ss]

There’s an overwhelming amount of dyno graphs out there that prove your formulations are flawed. I think this one is the icing on the cake... These motors respond well and perform when boosted. You can not deny this.

https://www.driftworks.com/forum/threads/sr20vet-engine-664whp-670wnm.268847/

Edit* Here is the landspeed racer dyno. Gasp! 1.5l making 400ftlbs of torque...

https://photos.motoiq.com/MotoIQ/Project-Cars/LSR-S13/i-vPBjWWV/0/L/LASTRUN-TQ-HP-L.jpg

[Kingtal0n]

There?s an overwhelming amount of dyno graphs out there that prove your formulations are flawed. I think this one is the icing on the cake... These motors respond well and perform when boosted. You can not deny this.

https://www.driftworks.com/forum/threads/sr20vet-engine-664whp-670wnm.268847/

Edit* Here is the landspeed racer dyno. Gasp! 1.5l making 400ftlbs of torque...

https://photos.motoiq.com/MotoIQ/Project-Cars/LSR-S13/i-vPBjWWV/0/L/LASTRUN-TQ-HP-L.jpg

That is not a dynojet bro. It also clearly says "flywheel torque" which is a dead give away that they are working backwards from RWTQ and RWHP with a number that somebody put into the computer at random (nobody actually knows what their drivetrain losses are, they can put whatever number they feel like)

We only use dynojet because they cannot be fooled. I can hex edit or adjust the torque from any other dyno, such as that one, to read whatever I want.
I could show you right now a 2L engine making 1000ft*lbs naturally aspirated. shocker

So far my dynojet predictions match every single 2.0L on the internet that I have found. Not one flaw with my formula or reasoning.
and so far the only thing you have shown me is 1 person who claims 24psi made 360ft*lbs of torque, which I also believe.

Send more dynojets of SR20VE and I will knock em down one by one. Don't try to fool me with other dynos lol. What do you think I am... noobie city over here

I want you to think about something very carefully. Energy comes from fuel, not boost. The boost just increases air density so you can inject more fuel.
Therefore, a/f ratio has a dramatic impact on torque, as does inlet air temperature.
If we hold those two variable constant, and assume ambient underhood air temp (100*F~) and typical gasoline ratio of "plenty of fuel" 11.5:1, what other factors remain?
There is displacement, Volumetric efficiency, compression ratio, and air density which is a function of air temp (a constant we are holding) and pressure (the boost pressure we are given as a constant).

Peak torque is typically achieved around 100% VE on all engines designed after 1982 as a constant 95 to 100% given, stock truck 2.4L KA24, stock truck 5.3L, stock 2JZ, stock SR20, all make near 95 to 100% VE so it is another constant we can ignore.

Notice how engine flow rate or head flow rate, or anything to do with the head beyond VE (which is constant) has absolutely nothing to do with torque output.
therefore it is impossible for anyone to take any 2L in the world, and get more torque from it given those constraints. It is thermodynamically, energetically, very unlikely without some novel technique (such as Direct Injection algorithms) to alter the BSFC and thermal efficiency of a power plant.
This is the same way engineers use modelling to determine power plant consumption, heat loss, shaft power, etc... That is, by holding some variables constant and looking what happens to the other ones.

In a more simple example, just use your imagination. Fill a cylinder to 100% capacity with the piston in opportune position and then fire the plug and measure the force generated by the piston's descent.
if you do this over and over with a 0.5L (1/4 of a 2L) cylinder you will find that no matter how many times you do the same experiment, it will generate the same torque or push given all identical starting conditions.
changing the "head" (cover over the cylinder) will not affect the torque unless it disturbs the compression ratio or efficiency of combustion. And even then the difference will be slight, and all heads made by Nissan after 1982 and all Heads made by Chevrolet made after 2002 contain the same cylinder head technology "fast burn" so there is little difference, nothing better has come along since for gasoline, and even if it does it will only be less than 1% superior.
why is that? How can I say that?
We know this because combustion has reached a pinnacle in our society. That is, thermodynamics has extracted all of the available energy (within 1% of what it attainable due to countless studies over the last 40 years by scientists and engineers on typical port injection engine platforms) regardless of who manufactures the engine because all engines in our modern time make use of similar computer modelling which puts the efficiency of every modern engine right near its calculable limit (the limit defined by calculus) of what is possible with gasoline.
This why no matter whether we check 1995 or 2015 or 2020 the fuel efficiency on modern engines and cars has not gone up by much if anything it has gone down due to stricter emissions regulations! That is to say that, if they could squeeze more than 1% or 2% from any modern gasoline engine it would have shown up as an improved fuel economy model, yet new corvettes and new Toyota supras with all their modern combustion gadgetry still provide a measly 15mpg to 22mpg or whatever, the same in 1995 and 2015. They are at the limit of efficiency!

[Def]

sigh... Zilvia...

A given amount of torque for a given displacement and intake MAP only works if the engine VE is constant. An SR20VE head will have way higher VE than a DET head. I personally saw ~10-14% higher on my old S13 in boost with the exact same turbo manifold, turbo, exhaust, intercooler setup. Only change was the VE. The VE needed more injector duty cycle at the same boost on the high cams everywhere to get the same AFR.


So if the boost is the same, the displacement is the same, but it needs 10-12% more fuel at the same RPM... what's happening to the torque? That's right, it went up.


I think you'd be surprised looking at old engines with really poor volumetric efficiencies and how much torque they generated per liter of displacement. You're likely just used to looking at late 80's, early 90's engines designs with all similar peak VEs (SR20DET, 4G63, 3S-GTE etc.).

[jr_ss]

sigh... Zilvia...

A given amount of torque for a given displacement and intake MAP only works if the engine VE is constant. An SR20VE head will have way higher VE than a DET head. I personally saw ~10-14% higher on my old S13 in boost with the exact same turbo manifold, turbo, exhaust, intercooler setup. Only change was the VE. The VE needed more injector duty cycle at the same boost on the high cams everywhere to get the same AFR.


So if the boost is the same, the displacement is the same, but it needs 10-12% more fuel at the same RPM... what's happening to the torque? That's right, it went up.


I think you'd be surprised looking at old engines with really poor volumetric efficiencies and how much torque they generated per liter of displacement. You're likely just used to looking at late 80's, early 90's engines designs with all similar peak VEs (SR20DET, 4G63, 3S-GTE etc.).

Thank you. I was hoping you?d respond...

[Kingtal0n]

sigh... Zilvia...

A given amount of torque for a given displacement and intake MAP only works if the engine VE is constant. An SR20VE head will have way higher VE than a DET head. I personally saw ~10-14% higher on my old S13 in boost with the exact same turbo manifold, turbo, exhaust, intercooler setup. Only change was the VE. The VE needed more injector duty cycle at the same boost on the high cams everywhere to get the same AFR.


So if the boost is the same, the displacement is the same, but it needs 10-12% more fuel at the same RPM... what's happening to the torque? That's right, it went up.


I think you'd be surprised looking at old engines with really poor volumetric efficiencies and how much torque they generated per liter of displacement. You're likely just used to looking at late 80's, early 90's engines designs with all similar peak VEs (SR20DET, 4G63, 3S-GTE etc.).


Your BS cannot confuse me. Your post contains no useful information or proof of anything.

Show some data, show some graphs.

Here is an entire thread of dynojet data for SR20VE engines:
https://www.sr20forum.com/threads/the-ve-dyno-post.184824/

ALL Of the dyno jets follow the trend of 150ft*lbs max for sr20VE Naturally aspirated. They ALL follow the same rule of 1psi per 10ft*lbs of torque. 14.5psi of atmospheric pressure @ 100% VE = 145ft*lbs of rwtq on a dynojet. This rule is for all 2L engines. No matter what is done to them, it is the same maximum limit.

I've examined around fifteen or twenty dynojet curves in this thread alone and all of them follow the same rule.
There has not been a single any significant difference between any of the engines from any manufacturers. Sr20VE and sr20det and 2jzgte and LM7 and LQ4 and L33 and (name any engine made after 1982) can achieve 95 to 100% VE with very simple mods, and many do it stock, some even trap higher VE with the OEM camshaft due to high inlet port velocity at low rpm with small diameter intake ports helping supercharge the cylinder. This is therefore a given and assumption for all engines, stock LM7/SR20VE/SR20DE/2JZGTE can do 95% to 105% VE easily, installing a long duration aftermarket cam actually can hurt their VE and drop torque and cylinder pressure.

[Kingtal0n]

Dynojet data for sr20ve vs sr20de engines:

SR20VE with a stock cam, near 90% or 100% VE easily due to excellent design
https://i.postimg.cc/90q0GgRw/sr20vestockcam1.png

SR20VE with what I assume is some kind of "cam upgrade" making nearly the same exact VE and thus torque:
https://i.postimg.cc/ydGW3Cdz/sr20ve-SR16-Camupgrade1.png

The Volumetric efficiency(VE) did not improve much, and as expected with a 'cam upgrade' the cylinder pressure is lower in some early rpm area because Volumetric Eff suffers in the low RPM ranges due to the effect of a larger cam on almost all engines.

Next, SR20DE engines fully modded out to show near 100%Volumetric Efficiency for comparison:
https://i.postimg.cc/t7QTDdWS/sr20de-modded-with-cams.png
https://i.postimg.cc/63qyQpB0/sr20de-with-s3-cams.png

Conclusion:
All 2.0L engines whether sr20de or sr20ve produce similar peak Volumetric efficiency, and we can tell this by comparing their peak torques with each other. The DE engine is not inferior to the VE Engine in terms of cylinder pressure, torque capability, or Volumetric efficiency (also called VE).

Despite an overwhelming number of variables which interplay with dynojet (humidity, temp, altitude, engine wear, age, etc...) ALL 2.0L engine display similar Volumetric efficiency and Torque capability regardless of manufacturer or model.

[RalliartRsX]

I stopped listening or caring when king constantly made all these assumptions (engine must be old, wrong dyno, etc. regardless of what the actual poster of the results state) to FORCE his narrative

Lol. Why do you guys keep resounding? All 2 liter engines produce the same VE is a whole bunch of bullshit when we are talking turbos and the heads ability to "efficiently" fill cylinders (read k series, VE or B series heads)

King has never dealt with a head or turbo that is able to fill engines way above 100% VE......lol.

Yeah next....

[RalliartRsX]

It funny, jr I had a written up a post and mentioned the LSR car. The browser stopped responding and I didn't bother to waste my time

King, that is NOT flywheel HP.

https://5523motorsports.com/road-world-speed-part-5-bearings-bones-unstoppable/

Here is a pic of Nick and JWT on the (chassis) dyno.........

https://5523motorsports.com/wp-content/uploads/2014/09/5523-Motorsports-SR15VET-Timing.jpg

https://5523motorsports.com/wp-content/uploads/2014/09/5523-Motorsports-Dyno-Tune-SR15VET-Jim-Wolf-Technology.jpg

[RalliartRsX]

Also, not all engines are able to fill to same VE at the same RPM. Also, pressure is essentially forcing more air mass into the same volume. PV = NRT. As Pressure increases, SO does Temp for the SAME volume.......

The VE head has the ability to flow MORE MASS of air vs a DE or DET head, hence it is able to get closer to 100% VE without a turbo. Add a turbo, and the above (albeit very simplified) equation comes into effect....

[jr_ss]

I stopped listening or caring when king constantly made all these assumptions (engine must be old, wrong dyno, etc. regardless of what the actual poster of the results state) to FORCE his narrative

Lol. Why do you guys keep resounding? All 2 liter engines produce the same VE is a whole bunch of bullshit when we are talking turbos and the heads ability to "efficiently" fill cylinders (read k series, VE or B series heads)

King has never dealt with a head or turbo that is able to fill engines way above 100% VE......lol.

Yeah next....

My problem with it, is he is spreading misinformation about what a specific motor with a specific head can produce and he’s wrong.

All his math formulas and knowledge yet he still isn’t open to expand his mind and think outside of them. That perhaps, something has changed and has allowed the increase of torque vs dismissing it and calling it bullshit. .

It funny, jr I had a written up a post and mentioned the LSR car. The browser stopped responding and I didn't bother to waste my time

King, that is NOT flywheel HP.

https://5523motorsports.com/road-world-speed-part-5-bearings-bones-unstoppable/

Here is a pic of Nick and JWT on the (chassis) dyno.........

I find it extremely amusing that he dismisses Def and calls his claims bullshit, when we all know who Def is.

He also talks about researching but goes on to regurgitate his rhetorical nonsense instead of researching himself...

Anyway, King these are legitimate power levels and real world data. As I said before, take it or leave it. At this point, I realize you cannot think outside of the box. It’s always going to be black and white for you.

[RalliartRsX]

jr_ss, if you are available, I am heading to JKTuning Tuesday for a redyno. I got a handle on the boost control issue and made a host of changes from the last time. I am hoping this time yields more positive results. I have to drop a new 12V power source for the Flex sensor, so will be bringing several gallons of E85 as well as doing a pump tune for the track. We will see how things shake out.

Car had the first track day Friday and performed well. I just wish all the heavy hitting machinery actually had some wheelers behind the wheel so I could learn a few more things.

[S14rebuild]

Luvn where this thread is going...good info and awsome popcorn fest!

[RalliartRsX]

Alot of the "good" info is based off of "invalid" assumptions outside of dyno graphs.....

I just read the first page. Another ridiculous and unfounded assumption....

The VE has the exact same VE (cylinder fill) as a standard DE head at 4000 rpm hahahahahhah! Have you even seen the flow numbers on a DE vs VE king? That is a grossly inaccurate assumptions and based off blind ignorance....

Goodluck to you king....you're gonna need it

[jr_ss]

Alot of the "good" info is based off of "invalid" assumptions outside of dyno graphs.....

I just read the first page. Another ridiculous and unfounded assumption....

The VE has the exact same VE (cylinder fill) as a standard DE head at 4000 rpm hahahahahhah! Have you even seen the flow numbers on a DE vs VE king? That is a grossly inaccurate assumptions and based off blind ignorance....

Goodluck to you king....you're gonna need it

I completely missed this... :picardfp:

[Kingtal0n]

Alot of the "good" info is based off of "invalid" assumptions outside of dyno graphs.....

I just read the first page. Another ridiculous and unfounded assumption....

The VE has the exact same VE (cylinder fill) as a standard DE head at 4000 rpm hahahahahhah! Have you even seen the flow numbers on a DE vs VE king? That is a grossly inaccurate assumptions and based off blind ignorance....

Goodluck to you king....you're gonna need it


I guess nobody here understands what Volumetric efficiency is.

Flow rate has absolutely nothing to do with Volumetric Efficiency.
I don't know why you keep quoting flow rate like it has anything to do with torque lol.

I am not the idiot here. You just have no idea what VE means, or how an engine works.

I have proven beyond reasonable doubt that both DE and VE engines/heads have identical VE with my previous post (https://zilvia.net/f/showpost.php?p=6385650&postcount=56) showing dyno graphs from both VE and DE engines which produce the same exact torque which = same exact VE.

Sorry but you need to learn more about engines before making these ridiculous posts.

[Kingtal0n]

Also, not all engines are able to fill to same VE at the same RPM. Also, pressure is essentially forcing more air mass into the same volume. PV = NRT. As Pressure increases, SO does Temp for the SAME volume.......

The VE head has the ability to flow MORE MASS of air vs a DE or DET head, hence it is able to get closer to 100% VE without a turbo. Add a turbo, and the above (albeit very simplified) equation comes into effect....


You have no scientific background, and completely mis-using those terms.

VE head does flow more mass of air than a DE or DET head- I agree with that, the dynos I posted prove it many times over.

However
1. this does NOT change a cylinder's volumetric efficiency, or have anything to do with torque!

2. the VE head and DE head both achieve the same exact VE as evidenced by the most recent dynojets I posted.

3. Never try to compare a non-dynojet to a dynojet, it doesn't matter fwtq or rwtq or whatever. non-dynojet is BS and I can make then say whatever I want, there is no standard. No way to compare other cars. That is why dynojet is so powerful and revealing.


...not all engines are able to fill to same VE at the same RPM. Also, pressure is essentially forcing more air mass into the same volume. PV = NRT. As Pressure increases, SO does Temp for the SAME volume.......


4. PV=nRT is an undergraduate equation created to simplify the true nature of gas molecules by using an 'ideal gas law' assumption - meaning if the gas was perfect and it's molecules occupy no volume and behaves ideally in a static NON-moving container/condition.

Which no gas ever does. PV=nRT does not include the terms for gas molecule size, gas molecule friction, gas harmonics/vibration/'waterhammer'/etc, and impurities such as water vapor (humidity), it does not include factors of flow rate. Its for examining gas in a balloon in a classroom, not a working moving engine. Don't ever bring it up on an automotive forum.


To eliminate any funny business with temperature, pressure, and volume, I used examples from naturally aspirated engine (identical Pressure) with the same sized engines (2L displacement Volume) at the same temperature range (50*F to 80*F Temperature). And they are all dynojets which utilize the same weight roller as a standard.

Here in this post we see that:
https://zilvia.net/f/showpost.php?p=6385650&postcount=56

Further,
Because " not all engines are able to fill the same VE at the same RPM" I specifically chose PEAK TORQUE since that is where PEAK VE or 100% VE is likely to occur for ALL engines manufactured in the world with no exceptions. Whether 90% or 105% makes no difference; we understand intuitively that results will vary by 5 to 15% in general, due to altitude, temperature, humidity, drivetrain losses, tire composition friction, etc... so when we see an extra or missing 10ft*lbs of torque from each 2L engine at atmospheric pressure it still 'makes sense' because those differences are subtle/slight.

However, what you NEVER see, is a 2L engine making 50 or 60ft*lbs extra on a dynojet at atmospheric pressure. What we NEVER see, and is impossible to witness, is a 2L engine making 180 or 190ft*lbs of torque, using typical compression ratios and drivetrain parts on gasoline at sea level. It would ring "WARNING: IMPOSSIBLE". Because none of those variables we discussed can alter the torque that high, on a dynojet.


I'm sorry that I have more education and experience than everyone here. I hate it. But you guys are hard headed and refuse to look at all of the data I have provided and instead insist on living in a world where you make up the rules. And I don't make up the rules.

[S14rebuild]

:drama::drama::drama:


This is why i log on.....

[RalliartRsX]

I'm an aerospace engineer by trade, with a masters.

I've interned at nasa and have worked on gas turbines for a few years.

Nope, not qualified at all lol.

I used that equation to simplify the discussion which I caveated above....

But meh you can continue to state as you wish....

[RalliartRsX]

Ps why are you comparing NA engines when the entire discussion and your dyno are all turbo engines?

Hahahahha!

[RalliartRsX]

Flow rate is in terms of cubic feet per min. The cubic feet is a volume. A volume has a specific mass associated with it like a box of air has a certain associated mass that is occupying the specific volume

The cross sectional flow area between the DE vs VE has changed enough where the VE head can flow more mass of air for a specific volume as due to the flow rate being higher, it can fill a specific volume (cylinder) with more air for a specific time (intake stroke). Hence why I state that a DE does NOT have the exact same VE at a given RPM peak RPM or whatever. The VE can fill the specific 0.5 liter volume at a much faster rate, and hence mass, than a DE during an intake stroke, which is a fixed constant.

If you are pouring water into a 2 liter glass, and you pour one at 2 l/sec and one at .5 l/sec do the glasses fill the exact same amount for a 2 sec pour? Because that's exactly what you are saying above....
The calculation for VE is
VE = (cfm x 3,456) / (c.i.d. x rpm)
So let me ask you this, if a DE flows say 100cfm @ 4000 rpm, and a VE.120, can you explain to me how both engines have the exact same VE if we are assuming 4000 rpm is peak torque or cylinder fill or whatever you call it?

But hey, if I have to extrapolate that idea, then maybe I give you more credit than I should....

[jr_ss]

:ddog::drama::drama:

[S14rebuild]

Ohhhhhhhhhhhhhhh. This is getn good!!

[RalliartRsX]

Ps who the fuck is comparing dyno outside of king? Dyno can all be manipulated and then on the same breath, you like "nope, that dyno isnt right because. Lah blah blah"

So many assumptions, missteps and are sorts of nonsense and king continues to conflate like 100 different....things

[RalliartRsX]

So I really want to harp on this. And I am going to bolt the fuck out of this since king knows it all just for effect

I guess nobody here understands what Volumetric efficiency is.

Flow rate has absolutely nothing to do with Volumetric Efficiency.
I don't know why you keep quoting flow rate like it has anything to do with torque lol.

I am not the idiot here. You just have no idea what VE means, or how an engine works.

.


The calculation for VE is
VE = (cfm x 3,456) / (c.i.d. x rpm)
.

Now, there is a much more nuanced equation which involves the ideal gas law, but for conversation sakes, since king thinks I am calling in an idiot because of his blind ignorance...

Spoiler alert; because you lack the understanding of a topic, DOES NOT mean you are an idiot. Another of your amazing leaps and assumptions....

:naw:

[RalliartRsX]

Here is the more nuanced equation

m_dot is....FLOW RATE! Specifically mass flow rate......or in terms of an engine CFM.

https://image.slidesharecdn.com/performanceofautomobile-150322065759-conversion-gate01/95/torque-power-volumetric-efficiency-and-their-dependence-on-unit-air-charge-has-been-discussed-12-638.jpg?cb=1427007647

[RalliartRsX]

Also, in the nuanced equation, you can see the ideas of a turbocharged engine unfolding and how it increases VE (temp rise due to compressing air, pressure drop or rise due to pressured air from the turbo's compressor)

I think I am done on this topic.......

[S14rebuild]

4 posts in a row... :goyou:

[jr_ss]

Also, in the nuanced equation, you can see the ideas of a turbocharged engine unfolding and how it increases VE (temp rise due to compressing air, pressure drop or rise due to pressured air from the turbo's compressor)

I think I am done on this topic.......

But are you really...?