how much boost?

[norcalslider]

can i throw at the stock T25 without a tune and not blowing it up or any knock?

[Sileighty_85]

http://i73.photobucket.com/albums/i235/Neil_85/Gifs/YourNuts.jpg

Probably would help more if you told us what engine.

If KA Im gonna say No

[KiLLeR2001]

11.5 psi w/ boost solenoid hooked up.

[kidbandikoot]

^
^ great choice of pic ... funny stuff

[KaminaSan]

12 psi max I would say.

You can run 13, but I'm sure a constant 13 will put you a little on the lean side, and your turbo won't last too long.

11-12 seems to be the most common boost for stock sr, considering that's what it came with from the factory.

[buentellomma]

12 psi max I would say.

You can run 13, but I'm sure a constant 13 will put you a little on the lean side, and your turbo won't last too long.

11-12 seems to be the most common boost for stock sr, considering that's what it came with from the factory.

Im pretty sure stock boost is 7psi, since that's what the waste gate is set at.... if it was 11-12 psi the sr would have came with injectors bigger than 370cc. I wouldnt go over 10psi on stock injectors

[1337]

11psi. 7psi is as good as a myth

[norcalslider]

7psi is wastegate which is nothing thats just when its gonna open..when i had my wrx and my boost controller went out i was running on wastegate psi which is 9psi.. oh and yes its for an sr20det,so you guys say around 12psi max

[clay9110]

i ran 14psi for two seasons. Finally decided to tear the motor down and build it and everything looks good and the turbo has no shaft play and is still in better condtion then most stock t25's.

[norcalslider]

yeah i mean ill push it and what not...what did you tamper to?

[jholman]

I run around 18-20psi for the whole track season. I had decent power numbers and I used a nismo FPR to get my AFR's in check.

I went with a billet wheel precision turbo about the size of a GT2871R and didn't run out of injector at 20psi....I completely ran out of MAF though.....I doubt you will max out your injectors with a T25 is all im saying

[norcalslider]

nice what did you tamper to tho..im looking for a power fc

[Drifting-pedobear]

how much boost should i run?

morr.
msgleangethszzz

[Chaw wee]

11-12 i would say. Ran 12 lbs, for over a year, pulled great and held just find.

[buentellomma]

i used the search button for you:
http://zilvia.net/f/chat/39094-psi-sr20-factory-turbo.html
7psi is the factory setting, if you can prove this wrong please post up your information to back it up, everything i searched came up 7psi and thats what my sr20 runs without a boost controller

Specifications for the Red Top SR20DET
(Found on the 91-93 180SX & Silvia)

Displacement: 1998cc (2.0 liter)
Cam Type: DOHC 16 valve, chain driven cam sprockets
Bore & Stroke 86mm x 86mm
Compression: 8.5:1
Horsepower: 205ps @ 6000rpm
Torque: 203 ft/lbs @ 4000rpm
Stock Boost: 7 psi
Throttle Body Bore: 60mm
Injector Size: 370cc/min
Turbo Specs:
Compressor: T-25, 60 trim 56mm BCI-1 compressor.
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Center Section: Journal bearings
Performance:
The stock turbo will be safe to 13-15 psi. After that, the turbo is past its efficiency range, and power increases will fall off and are not worth the risk of turbo damage. The engine should produce 230-250 RWHP at safe boost.


Specifications for the Black Top SR20DET
(Found on the 94-98 180SX)

Displacement: 1998cc (2.0 liter)
Cam Type: DOHC 16 valve, chain driven cam sprockets
Bore & Stroke: 86mm x 86mm
Compression: 8.5:1
Horsepower: 205hp @ 6000rpm
Torque: 203 ft/lbs @ 4000rpm
Stock Boost: 7 psi
Throttle Body Bore: 60mm
Injector Size: 370cc/min
Turbo Specs:
Compressor: T-25, 60 trim 56mm BCI-1 compressor.
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Center Section: Journal bearings
Performance:
The stock turbo will be safe to 13-15 psi. After that, the turbo is past its efficiency range, and power increases will fall off and are not worth the risk of turbo damage. The engine should produce 230-250 RWHP at safe boost.


Specifications for the S14 Black Top SR20DET with VTC
(Found on the 95-98 Silvia)

Horsepower: 220hp @ 6000rpm
Torque: 203 ft/lbs @ 4800rpm
Turbo Specs:
Compressor: T-28, 60 trim 60mm BCI-1 compressor in T-04B housing
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Center Section: Ball Bearing
S14 SR20DET's use a different ECU and harness, these are extremely expensive and hard to find.
Variable valve timing system and a different turbo are the significant changes from the S13 SR20DET engines.
The S13 uses a "low port" intake design vs. the S14 "high port" design.
Performance:
The stock turbo will be safe to 13-15 psi. After that, the turbo is past its efficiency range, and power increases will fall off and are not worth the risk of turbo damage. The stock engine should produce 250-260 RWHP at safe boost using stock turbo. Upgrading turbo, fuel and rest of need parts will yield 300-375.


Specifications for the S15 Black Top SR20DET
(Found on the 99+ Silvia)

Horsepower: 250ps @ 6000rpm
Transmission: 6 Speed, Close Ratio
Injector Size: 480cc/min
Turbo Specs:
Compressor: T-28, 60 trim 60 mm BCI-1 compressor in T-04B housing
Turbine: Inconel turbine wheel. Cast divider wall between turbine discharge and wastegate.
Center Section: Ball Bearing
This engine is expensive and hard to get. If you are on a tight budget, please consider other options as the money you save from buying this engine can be better used to build up a really nice red top.
Additions: 6 speed manual transmission. The 6 speed cannot be used on the S13 and S14 motors, and uses a different driveshaft. Speed sensor is located in the differential. The 6 speed is cool, but is not as strong as the 5 speed from the older cars. There is basically 6 gears inside the same housing that was designed to hold 5 gears. This makes the gears smaller and weaker, therby breaking more often.

[norcalslider]

awsome shit man..nice a 60 trim turbo that doesnt look it haha

[S14DB]

The wastegate is set at 7psi. The stock set up has a solenoid with a 10psi pill in it. 10psi is the normal operating pressure. The ECU only turns off the solenoid(7psi) when it goes into safe mode(check engine, knock, ect...).

Most people think stock boost is 7psi because they delete the solenoid when they do the swap.


I wouldn't run more then 12psi on the T25 and 15psi on the T28. After that you're just pushing hot air.

[buentellomma]

The wastegate is set at 7psi. The stock set up has a solenoid with a 10psi pill in it. 10psi is the normal operating pressure. The ECU only turns off the solenoid(7psi) when it goes into safe mode(check engine, knock, ect...).

Most people think stock boost is 7psi because they delete the solenoid when they do the swap.


I wouldn't run more then 12psi on the T25 and 15psi on the T28. After that you're just pushing hot air.
im not trying to say your wrong or insult you but my front clip did not come with a solenoid and the stock vacuum diagram doesnt show a hookup for a solenoid

[buentellomma]

i was wrong on the solenoid sir, i found a picture of a diagram with it on there..S13 Vacuum Diagram : SR20DET Forum (rear-drive) (http://forums.nicoclub.com/s13-vacuum-diagram-t305170.html)

[Chaw wee]

Most people think stock boost is 7psi because they delete the solenoid when they do the swap.

I'm pretty sure this is true. I was talking with a few friends the other day about sr swaps, and they said the same exact thing.

[Chaw wee]

i was wrong on the solenoid sir, i found a picture of a diagram with it on there..S13 Vacuum Diagram : SR20DET Forum (rear-drive) (http://forums.nicoclub.com/s13-vacuum-diagram-t305170.html)

Ahhh there we go lol.


back on topic, yeah just run around 11psi and you will be fine.

[S14DB]

im not trying to say your wrong or insult you but my front clip did not come with a solenoid and the stock vacuum diagram doesnt show a hookup for a solenoid
http://i51.tinypic.com/15xsdo7.jpg
http://i54.tinypic.com/i52bye.jpg

[norcalslider]

all cars turboed come with a stock solenoid

[buentellomma]

http://i51.tinypic.com/15xsdo7.jpg
http://i54.tinypic.com/i52bye.jpg
thanks man i found it, i posted a link of it when i corrected myself on that statement

[1337]

I run around 18-20psi for the whole track season. I had decent power numbers and I used a nismo FPR to get my AFR's in check.

I went with a billet wheel precision turbo about the size of a GT2871R and didn't run out of injector at 20psi....I completely ran out of MAF though.....I doubt you will max out your injectors with a T25 is all im saying

i would never take this advice

[Sileighty_85]

all cars turboed come with a stock solenoid
Not all do
the R32 RB20DET dosent use a Boost solenoid, Its tapped right off the compressor hosung and runs right to the WG actuator

See Right turbo
http://i73.photobucket.com/albums/i235/Neil_85/Miyukis%20Silvia/DSCN4092.jpg

[teh smithers]

Just to be clear, are we talking about turning up said boost without doing any tuning or fuel system mods? :eek3:

[norcalslider]

Just to be clear, are we talking about turning up said boost without doing any tuning or fuel system mods? :eek3:

correct,well i am..i have a hallman pro rx bc coming

[jholman]

I don't understand the fear in turning up the boost on a T25...Its so small its not gonna be moving enough air run you out of fuel.

[Corbic]

I don't understand the fear in turning up the boost on a T25...Its so small its not gonna be moving enough air run you out of fuel.

Its the turbo. The wheels like to grenade at +14psi.

[jholman]

Its the turbo. The wheels like to grenade at +14psi.

I've heard of this with the RB25 ceramic wheel turbos but never with the Silvia or Bluebird T25. Anything past 14 psi all they really do is just move hot air I've never saw one explode.

I agree that anything past 14psi doesn't yield any considerable gains but the point I'm trying to stress is that the factory fuel system can support more than 14psi.

And I have dyno charts to prove it

[Corbic]

I've heard of this with the RB25 ceramic wheel turbos but never with the Silvia or Bluebird T25. Anything past 14 psi all they really do is just move hot air I've never saw one explode.

I agree that anything past 14psi doesn't yield any considerable gains but the point I'm trying to stress is that the factory fuel system can support more than 14psi.

And I have dyno charts to prove it

Dyno, or air-fuel ratio?

I run 10psi at stock tune. Anything more is not worth it. You have to realize most 240 owners are broke asses. You just dripped every penny you have to swap the car, few want to run out and pop there motor for 10whp.

[teh smithers]

Not to threadjack, but I'm on a GT28RS- how much boost can my stock tune and fuel system handle? S14 SR.

[mattsil80wis]

i ran my t25 at spiking at 16psi and holding at 14psi...datalogged the car and the MAF and injectors were maxed out...car dyno'd 240hp/270tq with that setup...never a problem til i built it, but when i pulled apart the motor it looked great

[TheRealSy90]

12psi will be fine and you will probably still run alittle rich. I ran 12psi on mine and it was fine.

[norcalslider]

i noticed im on the stock MAF...would i be fine to switch to a z32 MAF or what ever it is on the sr without a tune then turn the boost up?

[JuMPiiN]

Honestly bro, disconnect your wastegate actuator until you get a tune just to be safe. You'll still build 1-4lbs but it's alot safer then saying someone messed with your wastegate and set it to 12psi you decide to turn it up a little more and melt a piston or something. Now your just SOL and fucked Bc you just spent your money swapping. It's errrr to be safe then sorry just my own opinion.

And I'm pretty sure anything over 14psi is pointless on a T25.

[norcalslider]

Honestly bro, disconnect your wastegate actuator until you get a tune just to be safe. You'll still build 1-4lbs but it's alot safer then saying someone messed with your wastegate and set it to 12psi you decide to turn it up a little more and melt a piston or something. Now your just SOL and fucked Bc you just spent your money swapping. It's errrr to be safe then sorry just my own opinion.

And I'm pretty sure anything over 14psi is pointless on a T25.

this is why im buying a boost gauge to really see what PSI im running...ive read around or someone post on this thread that you can run close too 14psi with no tune and be fine correct me if im wrong.

[norcalslider]

im glad i made this thread for us all it sure is helping me

[JuMPiiN]

Just be careful, I have a aftermarket Apexi turbo so I disconnected my wastegate just to be safe without a tune since I have no idea what it could be sat as before hand. Just saying be really careful. Bc it would suck to see that happen.

[2402NV]

With my last car, i had it on 13lbs with stock fuel system and it was running at 11.5 on the afr. So I wouldnt go over that at all.

[norcalslider]

actually 11.5 is really good which is where a tuner would shoot for.......i have another question even tho it doesnt have to do with how much boost,will any rear diff work for an s13 i have a welded one and im not liking it when i turn and shit

[handinpants]

disregard the information you don't want to hear people tell you. I wouldnt run over 10psi on my stock setup, I would recommend getting a digital boost controller though, and hook it up when you feel like it. but it gets addicting with the boost, and the cool thing is, that 10psi on your t25 will feel like nothing compared to 10psi on a 2871r, but hey if your wallet is thick and your motor is built, unplug the wastegate actuator and stick a golf tee in the vaccum line, and see what it can do......

I recommend waiting til you have the supporting mods to handle the extra strain on the motor, it will save you tons of cheese to do the job the right way the first time, then to half ass it and have to fix it all over again...

good luck, and don't forget to bring a towel


i used the search button for you:
http://zilvia.net/f/chat/39094-psi-sr20-factory-turbo.html
7psi is the factory setting, if you can prove this wrong please post up your information to back it up, everything i searched came up 7psi and thats what my sr20 runs without a boost controller

Specifications for the Red Top SR20DET
(Found on the 91-93 180SX & Silvia)

Displacement: 1998cc (2.0 liter)
Cam Type: DOHC 16 valve, chain driven cam sprockets
Bore & Stroke 86mm x 86mm
Compression: 8.5:1
Horsepower: 205ps @ 6000rpm
Torque: 203 ft/lbs @ 4000rpm
Stock Boost: 7 psi
Throttle Body Bore: 60mm
Injector Size: 370cc/min
Turbo Specs:
Compressor: T-25, 60 trim 56mm BCI-1 compressor.
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Center Section: Journal bearings
Performance:
The stock turbo will be safe to 13-15 psi. After that, the turbo is past its efficiency range, and power increases will fall off and are not worth the risk of turbo damage. The engine should produce 230-250 RWHP at safe boost.


Specifications for the Black Top SR20DET
(Found on the 94-98 180SX)

Displacement: 1998cc (2.0 liter)
Cam Type: DOHC 16 valve, chain driven cam sprockets
Bore & Stroke: 86mm x 86mm
Compression: 8.5:1
Horsepower: 205hp @ 6000rpm
Torque: 203 ft/lbs @ 4000rpm
Stock Boost: 7 psi
Throttle Body Bore: 60mm
Injector Size: 370cc/min
Turbo Specs:
Compressor: T-25, 60 trim 56mm BCI-1 compressor.
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Center Section: Journal bearings
Performance:
The stock turbo will be safe to 13-15 psi. After that, the turbo is past its efficiency range, and power increases will fall off and are not worth the risk of turbo damage. The engine should produce 230-250 RWHP at safe boost.


Specifications for the S14 Black Top SR20DET with VTC
(Found on the 95-98 Silvia)

Horsepower: 220hp @ 6000rpm
Torque: 203 ft/lbs @ 4800rpm
Turbo Specs:
Compressor: T-28, 60 trim 60mm BCI-1 compressor in T-04B housing
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Center Section: Ball Bearing
S14 SR20DET's use a different ECU and harness, these are extremely expensive and hard to find.
Variable valve timing system and a different turbo are the significant changes from the S13 SR20DET engines.
The S13 uses a "low port" intake design vs. the S14 "high port" design.
Performance:
The stock turbo will be safe to 13-15 psi. After that, the turbo is past its efficiency range, and power increases will fall off and are not worth the risk of turbo damage. The stock engine should produce 250-260 RWHP at safe boost using stock turbo. Upgrading turbo, fuel and rest of need parts will yield 300-375.


Specifications for the S15 Black Top SR20DET
(Found on the 99+ Silvia)

Horsepower: 250ps @ 6000rpm
Transmission: 6 Speed, Close Ratio
Injector Size: 480cc/min
Turbo Specs:
Compressor: T-28, 60 trim 60 mm BCI-1 compressor in T-04B housing
Turbine: Inconel turbine wheel. Cast divider wall between turbine discharge and wastegate.
Center Section: Ball Bearing
This engine is expensive and hard to get. If you are on a tight budget, please consider other options as the money you save from buying this engine can be better used to build up a really nice red top.
Additions: 6 speed manual transmission. The 6 speed cannot be used on the S13 and S14 motors, and uses a different driveshaft. Speed sensor is located in the differential. The 6 speed is cool, but is not as strong as the 5 speed from the older cars. There is basically 6 gears inside the same housing that was designed to hold 5 gears. This makes the gears smaller and weaker, therby breaking more often.

[norcalslider]

now if i do that i will get compressor surge which is more fatal and there would be no BOV and no where for the air to go. digital boost controllers i dont really like id rather stick with a MBC because it cant raise or lower unless it break,electronic ones are more prown to boost spike.

[KaminaSan]

now if i do that i will get compressor surge which is more fatal and there would be no BOV and no where for the air to go. digital boost controllers i dont really like id rather stick with a MBC because it cant raise or lower unless it break,electronic ones are more prown to boost spike.

No actually MBC are more prone to boost spiking.

An MBC gives the same amount of airflow no matter what, so let's say you hit 5500 RPM and your wastegate starts to fail, your MBC will still cause it to have less pressure than normal, and you will spike high.

With an EBC, when you go past a certain pressure, the solenoid disables completely, creating a stock flow, and the wastegate operates as if there was nothing there, thus reducing spike.

[Tantwoforty]

step 1. wideband
step 2. more boost
step 3. pay attention
step 4. profit

and the stock sr came with a solenoid mounted near the shock tower.
ive seen clips with them still intact.
the physical wastegate is preset to 7psi

[norcalslider]

^ see like i said before thats just wastgate pressure when its gonna open thats not the actual psi its pushing stock unless they set it up to only run on wastgate pressure...just like when i had my wrx my EBC took a shit on me on a road trip and i had to run on wastegate pressure till got to a hardware store and made an MBC.

[2402NV]

A MBC is just fine as long as it is a reputable one. You dont need to get an electronic one unless you just like spending money. My hallman holds 22 lbs nearly perfect on the dyno (22,21,22) and dosent spike much at all even when weather is colder.

[norcalslider]

well got a boost gauge installed and im hitting 12psi idk how because there is no MBC and the wastegate cant be played with so my other guess is the wastegate is stuck open