DaveW

How much hp is gained/loss with a 30 degree F difference in temperature? My best run in 50degF temp was 15.51 @ 85.88 mph. After installing the Borla cat-back my best run in 80degF temp was 15.53 @ 86.54 mph. I was also powershifting in the run with the exhaust installed so that might contribute to the higher trap speed. How significant of a factor is temperature?

LCP

...and 30 degrees of temperature might cost you half the HP you gain with an exhaust. Compare your 60' times for the 2 runs. Your 15.53 run with the exhaust may have had a slower 60' time, meaning you just didn't launch as well, but then ran faster over the next 1260' to have nearly the same ET (at least you got an extra 0.66mph through the traps).

SKS

Air temp means alot to a turbo

Clark@turbo5.com

MPH= HP
ET= Trq and skill.

Forget the ET. Look at your MPH.

If you ran faster in hotter temps.


It works.

Clark

Geza

Yes, but aerodynamic drag is also lower at higher ambient temperatures

LCP

and that ought to add 0.03mph to his trap speed

Geza

Is that something you calculated out, or just speculating?

LCP

Just speculating (thought I was trying to be optimistic too)

Augie

30 degrees on a normally aspirated car equates to a loss of about 4% in power, partially compensated for by lower drivetrain friction and lower rolling resistance. However, on a turbo car, you'll lose at least 5% or slightly more. See SAE Standard #J1349 for the particulars. Powershifting a turbo car can lead to substantial improvements over normal shifting, however, so the key question is: Did you make any passes after the exhaust change *without* powershifting? If so, what were the results?

PS - Figure the quarter mile speed and ET change based on the cube root of the power-to-weight change. Your mph change indicates a gain of 2.3% in power, not accounting for the powershifting.

Humidity and barometer also affect power, by the way. Do you happen to have those numbers?

12v 4 LIFE

Ur car is bone stock other than a exhaust and maybe chip.RIGHT? I HOPE!