Good Advice or Learning Curve?
 

Hey guys,

One of the things I check before a track day is my alignment. It seems after every track event my alignment shifts a bit. Sometimes it stays within its degree window other times it tips just beyond the window then needing an adjustment.

Is this normal?

If it is, hopefully this sheds some light on peoples future track day prep and has them looking into their alignment where they wouldn't have otherwise.

Thanks!

When you check your alignment. How much fuel you have in the tank? And what else you have in the Z?

hmmm, maybe 3/4 tank. Def more than 1/2. As for whats in the Z. If you mean mods they are in my signature. If you mean items its pretty much empty. 2nd car so no need for much "stuff" inside.

Interested to see which measurements changed

Every time you have the Z alignment checked. How much fuel is in the tank, and any items that you keep and remove from the Z. When making comparisons. You want to keep everything the same.

Gasoline weights about 6.3 lbs per gal.

Full tank is 19 gal = 119.7 lbs.

3/4 tank is 14.25 gal = 89.775 lbs.

1/2 tank is 9.5 gal = 59.85 lbs.

1/4 tank is 4.75 gal. = 29.925 lbs.

So for each 1/4 tank. You have about 30 lbs of weight that is almost centered in the Z. It might not seem like much. But it does have an effect.

I'd have to pull my alignment sheets to give you the exact changes but this time the rear wheels were the only ones effected. Only the Toe needed adjustment by about .10 degrees. Camber and Caster was clean.

Interesting. I will keep that in mind next time.