95' GS-T maximum boost ? Stock turbo.

[ttawd3s]

I'm going to be installing a boost controller and boost gauge tomorrow, and I'm trying to get an idea of the maximum boost this car can run EFFIENTLY. A friend of mine runs 22psi on his I/E 98' GST, and I know he is just super heating the air and causing his car to be slower, but he doesn't believe the idea of turbo effiecny. Both theses cars are stock turbo, IC, injectors, pumps, and everything else ( the 22psi car has something that eliminates fuel cut, I believe ).

The one I'm putting the boost controller on is a 95' GS-T with 83K miles, and he doesn't have anyway of seeing knock, SO i wanna set his boost at a SAFE level, I know stock is like 11-12psi, but I was thinking 14.5-15psi ?

I did a search, but I only came up with the maximum boost for other set-ups..

What turbos come on 95-99 DSMs ? I know about the older DSMs.. Is it a garret or something ?

 

[Syndicate13]

The stock turbo on 2nd gens is a Garrett T25. It won't hold more than 16 psi in high rpm. After 5500 it's starts to taper. You could set the max boost to 16 psi for a lot of torque in the midrange. If you try to push the tiny T25 past 16 psi it will significantly shorten the life of the turbo.

 

[ttawd3s]

All you guys prob hate the 2G T-25 turbo, but imagine having TWO turbos that can't hold more than 10.5 psi !!! With my bigger valves in my Stealth my stock turbos ( TD049B's ) will prob. max at 14.5psi at 4500rpms then fall to about 9psi to redline... Enter the nitrous !!

At 16psi the car won't get any knock ? or the ECU won't start to see knock and retard the timing ? Being its not my car, I don't wanna tell the guy to leave it at 16psi and the car blowup b/c of knock..

Thanx for the reply !!

 

[Phoenix_RsX]

I'd be safe and set it a 13-14 myself......

 

[boostineklipz]

Your friend runs 22 psi all the time. !!!!!!!! Tell him to turn that sh-t down. He is just heating up the Intercooler and killing the life off the turbo. From personal experienced, I dynoed my car at 15psi and made 202whp and turned it up to 22psi and hit fuel cut and then 18psi and made 196whp. I would say a safe and most of effective power wise boost level would be around 15-16 psi.

 

[ttawd3s]

Thanks guys, I'm gonna show him this thread, I've told him 100 times not to run over 17 ( 17 sounded alot better than 22 !! ), but he doesn't believe in turbo effiecy or something... I tried to tell him just b/c you can make that kinda boost doesn't mean its doing any good...

 

[larryd]

all I have to say

<img src="http://www.newcelica.org/larryd/dyno/02-01-02-dyno_comparison.jpg">

Can you make more power on more boost on the T25.. YES.. will it kill the turbo over time.. YES..

btw, dyno1 is 14lbs, dyno2 is 17lbs, and dyno3 is 22lbs.

 

[nine5raptor]

you can see form that why they used the T-25. hp sucks, but look at the torque.

 

[ttawd3s]

Tell a honda guy 222hp sucks !!! So, the turbo doesn't really super-heat the air... I doubt he cares about the turbo, its not like they are real exspensive... Was that dyno on pump gas WO/ water injection ? That torque is the reason DSMs are so popular, I have another friend with a 97' DSM and it is pretty darn torquy COMPLETLY stock... I bet before 1989 no one believed the a 2.0L 4 banger could make torque like that ( I'm sure the 86' SVO mustang guys believed it !!! )..

OK, so thanks AGAIN, so I'll just tell him to leave it on 22psi for race days, and keep it around 15psi for daily driving... I really figured that the ECU would pull timing b/c of knock ( from super heating ), but if that dyno was on 93 oct. then that little turbo is doing a great job, even though it can't hold the boost till redline !!

You guys say it will kill the turbo running it like that, but he's had the car since 53,000 miles, and it just hit 102,000, and it came with a boost controller so he's been hammering on that little thing for a while, Garret must of done something right... BTW he never uses synthic oil in it either, so that turbo should be done soon.... It will prob. end up on his CRX while the GS-T will get a 30G turbo with stock injectors ( he's not the quickest guy or should I say he doesn't research stuff before he does it ? )..

Another quick question, how much power can the AUTO. tranny with AWD handle before it breaks ?? ( I'm looking for an estimate of course). I bet a AUTO AWD car launches like a space shuttle !!

 

[Phoenix_RsX]

280 lbs of torque on a T-25?!?!?!?! Damn, I would have never known.......sweet.

but with the whole fuel cut, and killing the life of a turbo tho........

larry, I know you better than that, so I know you didn't drill 22psi on a t25 in the hole.

 

[Talon11]

Stock boost is more like 7-9psi if you still have the solenoid in there.

 

[Talonized]

I've heard running 14-16psi is the best bet....but then again, thats just what I've heard.

 

[Black95TSIawd]

I'm runnin 16psi as max boost on my car. Towards redline it dies down to about 10. Thats where the t25 loses all effinciency. Its not really a top end turbo. Midrange torque is awesome. My car is auto and it isnt that bad off the line. Turbo spools up fairly quickly.

 

[ttawd3s]

In an auto you shouldn't have ANY lag at all... From what I've learned about turbo regals ( all auto trannies ), you should hold the brake, while pressing the throttle off the line ( stalling up the convertor ), then you can leave the line with boost... In a FWD car that may not be a good idea, but in a AWD Auto that would be the shizzy, but you can't stalling the convertor for very long before the tranny will get WAY TOO HOT, so if you try this don't hold the brake for too long... Falls to 10psi ? that's like a 3S car !! Stupid mistu. engenners, what do they konw ??!!

 

[Booster2k]

Dont know if you saw my post or not but I put in a boost gauge this week and mine was dead on 12 stock with restrictor removed from the solenoid. I put on a MBC and cant get over 12 cause the bov is leaking too bad, so to anyone thinking about turning up the boost, get a 1g bov on there first, now I am waiting on my BOV before I can get more boost even with the MBC.

 

[InferiorWang]

ask ur friend if he has new injectors. Stock injectors cant flow more than enough fuel for about 17psi. and thats with a new fuel pump. If he has the stock fuel pump not rewired he shouldnt run above 15 or so to be safe. If the mixture gets too lean things will definitely get to hot and fugg thinks up.

 

[nine5raptor]

on the contrary, I ran 19 psi daily with stock pump rewired and 450's. this is the t25 we are talking about, the turbo falls off before it can outrun the injectors

 

[ttawd3s]

I wish, I'd read the post about the BOV leaking b/c it took a couple minutes to put the MBC in, then about an hour to install and wire the boost gauge, but the boost wouldn't go above 12psi... We tried EVERYTHING !!! So, I called one of my friedns ( the one running 22psi ) and then we went to his house to compare his to ours.. The whole time, I'm thinking I'm retarded, but even when they are hooked up the same the MBC never did anything... My friend dug up his old stock BOV, and swapped them out... BINGO !! Now it holds 17psi !! So after HOURS of trying to find out what was wrong, it turned out to be the POS BOV !!! What a ##### !!

On one of the runs to the parts store ( for fittings and hoses ) I power shifted my saturn and broke the tranny !!! Stupid GM !!!

 

[larryd]

Originally posted by Phoenix_RsX
280 lbs of torque on a T-25?!?!?!?! Damn, I would have never known.......sweet.

but with the whole fuel cut, and killing the life of a turbo tho........

larry, I know you better than that, so I know you didn't drill 22psi on a t25 in the hole.

ttawd3s.. yes the dynos were all on pump gas and on the stock SMIC.

Phoenix_RsX.. I have no clue what your talking about??