Flyboy

normally with 93 octane the motor is knock limited from ever getting near MBTT. The main benefit from running high octane gas, 100 or up, is that you can continue to advance the timing nearer to MBTT without encountering knock. I don't think anyone would dispute that you make a significant amount more power on race gas with a program that runs appropriate timing.

Water injection lowers the charge air temp, which helps with power production, but I'm pretty sure there aren't any WI kits that make close to race gas power from the temperature recovery alone. WI displaces oxygen in the air, so there are tradeoffs to using it.

s4what?

Correct me if I'm wrong, but APR & AWE 100 octane programs have significantly different boost curves from their 91/93 programs. I believe most of the power gains from high octane come from being able to keep the boost up and to not have to taper up top as much, and not so much from timing advance, which has a limited effect.

Mike2kS4

and midrange boost, not top end boost. K04's don't flow very well past 22psi in higher RPM's. Look in the rest of this thread to figure it out yourself.

PSmalls::AnalRetentiveNumbNut

Or maybe I'm confusing their K04 stuff with their K03 stuff.

K03 stuff definitely has less boost on race gas program and it's still *significantly* faster.

Flyboy

in the timing. There's quite a jump between the 93 and 100 programs, and it goes up even more on 104.

Before APR revised their code, the race gas program ran less boost than the 93 octane, but made up for it with the timing.

s4what?

Try the excel program link in my sig to do the maps