why is my car faster when it gets hot?

[novaderrik]

at the track with the T-Type friday night, i made an interesting discovery. if i made back to back runs, the second run would always be a good tenth and couple of mph faster.
the 60 foots were always better- and i think that's where i made up the et, hence the smaller gain in mph.
if i tried to cool it down between runs, all it did was slow down.
could it be the half a tank of E85 i'm running- al lthat alky in there doing a kind of "chemical intercooling" or something like that, and it just likes being hot?

 

[turbo6x2]

My hot air generally picks up after it gets hot. I generally take it through the pits and warm it up before any initial runs anyway. That way everything is at operating temperature. Especially the transmission.

 

[Bryan C.]

Thermal efficiency. This is the same reason newer cars generally are made to run at temps over 200 degrees.

 

[novaderrik]

my Nova always slowed down if i did some "round robin" runs- even if the engine temps were the same, the second pass was ALWAYS slower. and i was running the same set of wheels and tires that are in the Regal now, so tire heat isn't an issue.
but the Nova wasn't a turbo car- it was a vortec headed, HOT cammed 355 with a 4 speed and 3.70 gears.
oh,well, i guess i just need to get the Regal as fast as the Nova- i've got almost a seccond in the 1/8th to find somewhere...