Dynoed my 2005 QC!

[BigRed460]

10 PSI will still be 10 PSI.

The difference is that there will still be less oxygen to burn, hence the loss of HP.

a supercharger that makes 10psi at sea leval won't make that at higher altitudes, a turbo will still make all 10psi. If the wast gate sticks a turbo thats set up for 10 psi can make 20+(till it comes apart)... a s/c is spinning off the belt, it never changes boost...

 

[Silverback]

I think what he was saying was that, given a supercharger setup rigged to make 10psi of boost at sealevel, you won't be making 10psi of boost at 5,000ft altitude. You'd have to go with a smaller pulley to make that supercharger spin faster and "collect" more of the less dense air...

Air at 10psi will have the same oxygen level whether it was compressed from sea level or higher altitudes...

If true, then explain why the NHRA boys run slower at Denver. They run smaller pulleys for the same boost level, but always have less HP.

Same is true of any turbo engine. It will not have the same HP at higher elevations with the same boost level.

 

[rottenronnie]

If true, then explain why the NHRA boys run slower at Denver. They run smaller pulleys for the same boost level, but always have less HP.

Same is true of any turbo engine. It will not have the same HP at higher elevations with the same boost level.

I agree with you Silver. A turbo can and may spin faster to make the desired boost; BUT at higher altitudes, that boosted air pressure still contains LESS OXYGEN (the key here). And, lower power levels than at sea-level. You are NOT going to "create" oxygen by boosting...

Ron