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'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

RZRSHARP_240SX

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?

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Comments should be taken as Opinions not as Statements of Fact

Kaisen

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

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

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~


built s13 engine 9:1 forged etc... but slightly smaller turbo (42lb/min unit)

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

Kaisen

Doesn't make any sense right?!

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?


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 ) = 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

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=5...&postcount=453


This person as well:

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

S14DB

What is your ECU and Boost control?

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Kaisen

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

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AV FABRICATION

Built thread sr20vet s14
http://zilvia.net/f/showthread.php?t=535574

S14DB

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

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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)

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Built thread sr20vet s14
http://zilvia.net/f/showthread.php?t=535574

Kingtal0n

this


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.

[IMG]s293.photobucket.com/user/BlueDragoon0/media/P1010134.jpg.html[/IMG]
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...s-Brian-Crower


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

some evo dynos for comparison
https://www.socalevo.net/threads/135...P-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/ev...-thread-3.html

Kaisen

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.

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

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

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

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-he...w-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.

__________________

95 240sx RB20 415whp
91 Nx2000 VVL yo

Kingtal0n

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.