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View Full Version : Is 13 psi safe on an SR with stock injectors?

sr20tom
05-05-2005, 04:10 PM
I have an S13 SR20det Blacktop and a walboro 255, and stock injectors. I sometomes cranck up the boost to 13 psi and dont know if its really safe? I have the Apex 550s and a z32 maf but did not install them cause gas is 2.50/ GAL. When i crank it up, my Greddy EGT gauge doesnt really go up that high on boost, but i still want to be safe. Is it ok to up the boost that high on a stock motor with a FMIC and stock injectors?
Yoshi
05-05-2005, 04:49 PM
I have an S13 SR20det Blacktop and a walboro 255, and stock injectors. I sometomes cranck up the boost to 13 psi and dont know if its really safe? I have the Apex 550s and a z32 maf but did not install them cause gas is 2.50/ GAL. When i crank it up, my Greddy EGT gauge doesnt really go up that high on boost, but i still want to be safe. Is it ok to up the boost that high on a stock motor with a FMIC and stock injectors?

You're fine, tho personally I wouldn't leave my boost at 13 for normal driving or even track events, just to be safe. Not because your out of your injector's duty cycle, but because you're hitting the redline of the stock T25's efficiency range, 11 or so would be fine all day long, but I wouldn't do 13 unless it was just for drag or something.

Cover Yoshi's Arse Statement: This is all provided that all your components are tip-top shape, the engine is properly broken in and doesn't have too many miles, the driver doesn't do something stupid (cuz that happens), AND you live in a parallel universe where there is no such thing as mechanical failure.

That being said, if I were u, I'd hit 10-11, it give u a little fudge room for overboost or spike... granted, that's not a whole lot of space, but it's better than sitting right at the edge of the turbo's efficiency.... excessive heat is bad... oh... and along those lines, do you have a FMIC to cool all that down?

edit:
nm the FMIC part, u mentioned that at the end of your post and i missed it.
Var
05-05-2005, 05:04 PM
I run between 10 and 13 on a stock t25.(set it to 13.5 and it drops to 10 by redline) it's not really technically efficient past 10psi but my butt dyno doesnt say so. Also it's ok for the turbo up to 14psi. You wont damage it if it was in good shape to begin with but obviously it causes more wear and tear.

An analogy between turbo's and engine

Your turbo's max boost is like your engine's redline. Even though your turbo isnt making much more power all the way up high(just like camshafts in an engine drop off power towards redline), you may keep it up there for certain situations. Taking it past 14psi--> Think of every next psi like a couple hundred rpm past redline.
mr_240sx
05-05-2005, 06:04 PM
well your boost might be set at 13 psi but when do you really hit 13 psi when driving it in the city???? i have mine set at 13 psi and i drive it daily and dont usually hit 13 psi driving, but i have been at 13 psi for a year and nothing has happened. i do have fmic, and 255 fuel pump.
sepulchral
05-05-2005, 08:29 PM
my boost goes to 15psi then drops to 10-12psi but the 15psi really jumps me in the lead... 15psi for 2 years .... whats wrong with that?
mr_240sx
05-05-2005, 09:03 PM
my boost goes to 15psi then drops to 10-12psi but the 15psi really jumps me in the lead... 15psi for 2 years .... whats wrong with that?
im sure your damaging your turbo when you boost at 15 psi!!
Var
05-06-2005, 10:38 AM
He's been running it for 2 years. So let's just call it wear and tear instead of damage.
autobahNESSA
05-06-2005, 12:15 PM
The trubo can spool much higher, however it will lead to premature wear and tear. plus anything really above 12psi on a t25 just creats more heat then anything else.
Mine also drops to around 10psi in the higher rpms. I have it set at about 12-13psi also.
mr_240sx
05-06-2005, 02:47 PM
The trubo can spool much higher, however it will lead to premature wear and tear. plus anything really above 12psi on a t25 just creats more heat then anything else.
Mine also drops to around 10psi in the higher rpms. I have it set at about 12-13psi also.
thats weird becuase when i drive mine hard and it creates full boost, it stays at 12-13 psi through out all the rpm's all the way up to red line.
DTS
05-07-2005, 08:51 AM
thats weird becuase when i drive mine hard and it creates full boost, it stays at 12-13 psi through out all the rpm's all the way up to red line.

then you dont have a T25. the t25 dies past 6350 ish and by the time you get to 7500 your just waisting time and gas.

a new t25 is 150 bucks...they are a dime a dozen who really cares if your turbo wont last 5 years and only lasts 1. you can get a t28 for a 200 more anyways
crazy9ceguy
05-07-2005, 09:12 AM
sure ur fine, i have a redtop with stock injctors with a t28 and i run 18 psi and nothing has happened for a year.
mr_240sx
05-07-2005, 05:03 PM
then you dont have a T25. the t25 dies past 6350 ish and by the time you get to 7500 your just waisting time and gas.

a new t25 is 150 bucks...they are a dime a dozen who really cares if your turbo wont last 5 years and only lasts 1. you can get a t28 for a 200 more anyways
well i havent upgraded my turbo so if i dont have a t25 then it must mean that i got the motor with another turbo. :goyou:
sr20tom
05-08-2005, 11:44 PM
Thanx for all the help.
I drive everyday at 7.5 and when i do go to the track i wanted to bump it up to 13. Have only done it once, but i got kincked out for doing donuts :( (It was raining and i actually spun out after a lounch and slaming 2nd, 6 puck :( )) I do hit the high boost on the EFB II once in a while on the street when i get bored.
Again
Thanx for all the help
Much appresiated