I wanna know about how much horsepower I can expect from each PSI I add to the engine
The question is impossible to answer simply. It depends upon backpressure, compressor and turbine efficency as well as how well the engines tuned, fuel quality and where in the compressor map you are dwelling.
It can go from almost nothing to as much as 30-40 hp at the extremes.
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There can only be one Icy Hot Stunta, Don't Hate.
The question is impossible to answer simply. It depends upon backpressure, compressor and turbine efficency as well as how well the engines tuned, fuel quality and where in the compressor map you are dwelling.
It can go from almost nothing to as much as 30-40 hp at the extremes.
I read somewhere that 1 psi = about 11 Hp. Probably 10 or 9 on a dead stock car , and the 160-200 Hp difference between the non-turbo and the factory 5 psi on the turbo Zs would seem to bear this out.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
well it can't be a factory of 5 because I am running 7. Is 5 what they ran on the baseline for the 87? If so I might be putting out up to 220 FHP... Well hmmm so if I raise it 4 psi like I want it should be about 40 horsies on the flywheel
You can't just say for every psi you will gain this much hp. It all depends on turbo efficiency. Going from stock boost to 8 psi is around 20 more RWHP.But going to 12psi will only net you another 10 rwhp. It is all related to heat and turbo efficiency. The reason you stop making so much power at a certain point is because heat increases and efficiency decreases. This is shown with the power increases from 6.7-8-12psi. Basically above 10psi the turbo is producing more heat then power. Get an intercooler though and you can turn up the boost with ample power increases as long as you can supply enough fuel. Of course at about 14.5psi your turbo is maxed out completely and after this point you will reach dangerous inlet temperatures and dangerous backpressure associated with the compressor and exhaust manifold. This is not taking in affect the exhaust system itself. Just merely the manifold and turbocharger.
Even though Ballistik will say otherwise I am adament on the fact that you will need an intercooler to sustain above 8psi for long durations. During the winter time 10psi should be safe without an intercooler but any other time of the year I would suggest only running 8psi if you do not have an intercooler. You can of course turn up the boost for short durations of time (like a race) without any issues. Also since I am on the subject without computer and fuel system upgrades I would not suggest turning the boost up beyond 14psi at any time.
well it can't be a factory of 5 because I am running 7. Is 5 what they ran on the baseline for the 87? If so I might be putting out up to 220 FHP... Well hmmm so if I raise it 4 psi like I want it should be about 40 horsies on the flywheel
5 psi in 1985 , I beleive. At some point they switched to a T25 turbo boosting more , with a resulting 5 more Hp (In 1989 actually) ......... When I hooked my Autometer up to my car , it read 5 psi at full boost , so I'm assuming most Z31s are doing the same. Can't confirm it anywhere , however.
I will have to disagree with what JamesZ has said about boost pressure though , Z31.com states that 14.5 psi is the efficiency limit for the T3 , so therefore me running at 15 psi is not too far out of it's range. The stock limits are fairly high on everything , you should be able to get 270-280+ whp out of everything , this with no upgrades at ALL.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
so you suspect that you are running around 270-280 WHP with the boost you are running? No intercooler? Are you just using premium pump gas?
I'd like to think so but I haven't dynoed yet , so it's all conjecture at this point. And all I use is 91 octane , which is the highest common street octane we have. You can buy up to 116 at some scattered stations , all of which are over 20 miles from me..........
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1992 Yamaha FZR 1000. 145 Hp, all stock..
hell I would just use that octane booster stuff. That should work shouldn't it
Not as well as you might think. The typical bottle of octane booster will raise your octane by 1/10th of 1 point. Even the infamous Outlaw brand only raises it by about 1/2 a point , if that. So , if you want 95 or higher octane........you do the math.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
I would say 270-300 flywheel hp would be the max limits for the stock fuel system, turbo, and computer. I can achieve a high 13 (if not a tad bit faster) with only 230-240rwhp.
I would say 270-300 flywheel hp would be the max limits for the stock fuel system, turbo, and computer.
Z31.com agrees. So do I , for the most part , but I think the turbo and the ECU can handle more. But the fuel pump definitely needs to be upgraded. A Walbro 255 is sufficient , and out pumps the TT 300Z/GTR fuel pump by a few lph.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
damn, I bet you could go faster... like 12.9 @ 110 if you had a T3 and an FMU
On a T25, don't run more than about 10-12 psi. You can see about 240 rwhp if you are lucky. If you have a few bolt ons or bolt offs (exhaust and intake pieces) you could make about 260-275 rwhp and 310-340 Lb Ft.
damn, I bet you could go faster... like 12.9 @ 110 if you had a T3 and an FMU
On a T25, don't run more than about 10-12 psi. You can see about 240 rwhp if you are lucky. If you have a few bolt ons or bolt offs (exhaust and intake pieces) you could make about 260-275 rwhp and 310-340 Lb Ft.
Actually I don't think the T25 turbos were installed til 89.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
When I hooked my Autometer up to my car , it read 5 psi at full boost , so I'm assuming most Z31s are doing the same. Can't confirm it anywhere , however. 
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