10 HP/lb of boost?

[MrMorgan]

Does that sound right. Buddy here is telling me his 2010 nytro is pushing 240 HP on 12 lbs of boost with just premium gas. Sounds high to me and he has not dynoed it.

Any experts to back or refute this?

 

[maxwell]

thought that was a general rule of thumb. sounds about right. although it should be higher at 12lbs

 

[gotboost]

the way it works is for every pound of boost = 10 hp :d

 

[sledhed17]

Not a turbo genious here but 12lbs of boost sounds a hair high to be running pump gas on

 

[gotboost]

yeah might be abit high on prem fuel i would be running some race gas and maybe he has a head shim :d

 

[maxwell]

12psi at elevation with premium might be ok? i have a friend running 10. not sure if thats the limit or not on the yamis

 

[bigdawg]

Im running 12 Ibs @ 100% race fuel......and 10 HP per Ib is high more like 6.89Hp per Ib..... just my 2 cents

 

[TABSTER]

what he said..........7 hp per pound of boost.
Approx.

 

[overkill131313]

what is a stock 06 apex putting out? because at 18 psi I get to add another 126 hp!

 

[shawnmcgr]

I would think 6psi is about the max you could go without shim, race gas or low comp pistons. I'm just going by the attached which was done up by someone much smarter than me. It also shows 220hp to be about right. That's 7.5hp/psi.

 

[Pistonbroke]

I would think 6psi is about the max you could go without shim, race gas or low comp pistons. I'm just going by the attached which was done up by someone much smarter than me. It also shows 220hp to be about right. That's 7.5hp/psi.

Very cool! Thanks for this Shawn, I downloaded this and am playing with it.

 

[shawnmcgr]

Very cool! Thanks for this Shawn, I downloaded this and am playing with it.

No problem, takes some of the hokus pokus out of it.

Love that avatar man!

 

[summit889]

Not a turbo genious here but 12lbs of boost sounds a hair high to be running pump gas on

I ran 17-18 all last year pump gas 5-7000 ft. With a headshim. 12 is fine on a nytro.

 

[summit889]

There is no definite lb. Of boost = this much hp. It all related to volume of air. A gt28 at 12 lbs makes alot more hp than a gt25 at 12lbs. 10 hp / lb would be on the very high side. 7-8 would get you close.

 

[4mcntrls]

I thought that @8 psi you were about stock hp X 1.5 and at 14 you were about stock hp X 2?

 

[glengine]

These numbers must just pertain to the yammies? Cause i've seen a XP with a aerocharger53 turbo on it be put on a dyno in edmonton and @10 lbs boost it made 203hp. And that was on straight race gas. I saw a M1000 with a B/D turbo kit on the same dyno @10lbs boost make 250hp and 197ft.lbs of torque, This one also was on on staright race gas.

 

[shawnmcgr]

There is no definite lb. Of boost = this much hp. It all related to volume of air. A gt28 at 12 lbs makes alot more hp than a gt25 at 12lbs. 10 hp / lb would be on the very high side. 7-8 would get you close.

I agree, the temperature of the charge air will seperate 12psi from 12psi. 12psi @40C will have less air volume (@ STP) than 12psi @ 20C (assuming relative humidity is the same). But if the temp of the charge air is the same then 12psi=12psi whether it's GT25,28 or supercharger, the volume of air getting into the motor is exactly the same.

Total hp getting to the PTO is also affected by the load the compressor or charger is putting on the motor to get the 12psi. Compressors that are more efficient @ 12psi will end up with higher PTO hp (assuming same charge air temp).

Sorry to go all Bill Nye the Science Guy on ya!

 

[summit889]

Not totally sure I get what you are saying. Are you saying a gt25 and 28 will make the same hp at the same boost?

 

[Pistonbroke]

The GT28 will make more HP at the same output boost level, as it is a larger pump, putting more lbs/hour of air into the motor.

 

[overkill131313]

isnt 12 psi on a 25 the same as 12 psi on a 28????? I thought 12 psi was 12 psi but the 28 will deliver more air say 25 psi when the smaller turbo just wont get there? the bigger turbo will give you more air (when the smaller one just stops) but will also take more time to spool up...... but what do I know with my grade 6 education.......it has been a few years since I have played with turbos lol!