# horsepower



## rico2 (Jan 6, 2006)

hay guys just wondering if anyone would know the aproximate hp of the stock turbo set at 12 psi? any help is appreciated! thanks!


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## Zen31ZR (Mar 24, 2004)

I have read a few places that 10 Hp per psi of boost is a good number to use. I'm not sure what it's based on or how reliable that figure is, but I've seen it mentioned more than one place. The only way to know for sure is dyno the car. But I would guess that you might be pushing about 250-270 Hp at the crank. I ran 16 pounds myself and managed high 13's at the strip with an open diff and crap street tires.


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## AZ-ZBum (Nov 21, 2004)

a stock 89 with 12psi will be detonating to hell and back. not recommended.


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## Zen31ZR (Mar 24, 2004)

AZ-ZBum said:


> a stock 89 with 12psi will be detonating to hell and back. not recommended.


 I disagree, 12 psi is easily handled by the stock systems. Actually up to 14, from what I've read, and you have the same information I do... Beyond that, hold on to your wallet with both hands.........


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## AZ-ZBum (Nov 21, 2004)

Not with the T25 and the higher compression motors they won't. 12PSI is past the efficiency limit of the little turbo.

Now the T3 and the 7.8:1 are better. But it better be damn cool outside and running really high octane (100+) to run 14psi.


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## Zen31ZR (Mar 24, 2004)

Maybe I just ran in different circles, the guys I knew with T25s in their DSMs had them at 14 psi all the time. 16-17 psi is definitely the limit for that tiny turbo, though. That was also on a 2.0 motor, I'm sure its much less on a 3.0 engine. The T25 just can't push that much air. Maybe he should do a T3 conversion. As far as running outside the turbo efficiency, it can be done consistently, but only for short periods of time. I never went past about 1 mile with my 85T at 16 psi. Most people don't have the attention span to watch both distance travelled and pounds of boost that carefully, though. That's why most tuners overbuild their cars, so they don't have to pay attention. People like me who run beyond the limit all the time, we pay a lot of attention to guages and engine sounds. The one time I didn't, it proved to be a disaster.


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## AZ-ZBum (Nov 21, 2004)

Yes. 12PSI on a 3.0L is much different than 12PSI on a 2.0L.


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## my86z (Jun 19, 2006)

Zen31ZR said:


> Maybe I just ran in different circles, the guys I knew with T25s in their DSMs had them at 14 psi all the time. 16-17 psi is definitely the limit for that tiny turbo, though. That was also on a 2.0 motor, I'm sure its much less on a 3.0 engine. The T25 just can't push that much air. Maybe he should do a T3 conversion. As far as running outside the turbo efficiency, it can be done consistently, but only for short periods of time. I never went past about 1 mile with my 85T at 16 psi. Most people don't have the attention span to watch both distance travelled and pounds of boost that carefully, though. That's why most tuners overbuild their cars, so they don't have to pay attention. People like me who run beyond the limit all the time, we pay a lot of attention to guages and engine sounds. The one time I didn't, it proved to be a disaster.




Yes, those T25's are basically too small for a 3.0L anyway. That's why they're only pushing 4.5psi in factory form. And to say you want to push 12+ psi from them. WOW. 

And I wouldn't bother with a T3 conversion. Well, maybe, if you can't find an upgrade T25 for a decent price. But, if I were in your shoes, I'd be looking at the GT2871. Direct bolt onto the manifold. Only thing you'll have to do is get the oil lines and downpipe fabricated to work on the car.


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