Head wind vs tail wind-ET impact

[Kegracing]

I ran a 68 Camaro for several years, mostly 10.90 stuff. Had the stock spoiler on front and rear. On the T-stop it ran 10.90 at about 125-127 and ran 10.40's off, with most of my motors.

Direct headwind was -.15 in quarter, and tail was about +.10... on my car. Everyone is a little different. Also, the JEGs log books used to have a guide on the first page... not sure if it still does or not. Don't have one handy.

Topeka track runs about due south...

Good luck.

Ken

[Tony Curcio]

The Jegs log book said that 8 mph wind = .05 ET, using a 9.90 car as an example.
It doesn't address differences in frontal area.

My experience with a Camaro running a little slower than yours matched the Jegs formula pretty well for a head wind, but is affected a bit less by a tail wind.

[cad]

Thanks guys. I appreciate it!

[Tom Meyer]

My Chevy II at topeka with a wind change you are talking about was anywhere from 15 20.That place is a dailing nitemare with the wind go luck. Tom

[cad]

Thursday looks like rain and Friday looks beautiful, so we'll get the gambler in.
We get 1 time trial Saturday and straight into Race of Champions, so at least we get 1 shot.

[gsa612]

Originally Posted by Tom Meyer

My Chevy II at topeka with a wind change you are talking about was anywhere from 15 20.That place is a dailing nitemare with the wind go luck. Tom

X2, the layout of the track at topeka makes it like a wind tunnel if you got a headwind, lost 2 tenths when the wind picked up, the da only changed a couple hundred ft. gsa612