Stump the Group - Weird Math

It took 18 years, but you finally proved 15yr old Face wrong when he exclaimed "I ain't never gonna need to use this stuff!". I guess I can take solace in that I at least know and understand how dividing by fractions works =p

Thanks for the assist. If I can pull this off, you just saved me $900+ in parts and burnt up tires, not to mention increased purse and pride for better finishes. I appreciate it! =)

I always thought camber in race cars was to compensate for the increased lateral g's, not the angle of he roadway.

Will you only change only the right (high) side suspension, or do you do the opposite on the left side, since that side will be lower?

Quote: Ayecarumba

I always thought camber in race cars was to compensate for the increased lateral g's, not the angle of he roadway.

That's sort of right. It's to address what happens to the tires when you increase lateral G.

Camber (as well as everything else in the suspension) is all about maximizing and maintaining the contact patch, the footprint, of your tire. Even if you were road racing with flat corners, taking the corner causes the tire to deform and "roll". Here's a perfect illustration



You can see the part of the tire that is the tread. And although the contact patch is too dark and not visible, you can imagine how that tread is positioned during the deformation. It has "rolled over". The inside of the tread is off the ground, the outside is now rolling on the sidewall. Not only will this cause a decrease in traction due to a lesser contact patch, it'll burn that shoulder off before the tires are even up to temp.

If he dialed in some camber, that flex will bring the tread to him instead of away from him, and the contact patch would increase as it does.

Now, I don't have super sticky slick tires, and I'm not screamin' 140mph into Eau Rouge. But I am piling dead on into 22* of banking. I dunno how savvy you are with how much that is, but it's more than NASCAR's Indy, more than Vegas, more than Michigan... it's more steeply banked than 14 of 22 NASCAR Sprint Cup tracks. It's a hell of a chop. So even though I don't have the traction or the speed to flex my tire that much, the exact same condition happens. The inside of my tread gets lifted off the ground and I'm rolling along on the sidewall.

That picture up thread was no joke. That was 12 miles on that tire before I took it down to the belts.

Quote: AyeCarumba

Will you only change only the right (high) side suspension, or do you do the opposite on the left side, since that side will be lower?

I changed both, and the inside went the opposite way. It's always the "right side" of an individual tire that gets punished, so it wrecks the OUTSIDE of the right but the INSIDE of the left. Make sense? (everyone gets hung up on that ;)) My right tire needed negative camber to kick the bottom out, and the left tire needed positive camber to kick the top out. Basically, it needed this...



Unfortunately we are quite limited indeed on RF camber. I know they do it to keep the costs down, as it's a few hundo for a camber kit. But burning down a tire a week ain't cheap. If camber made a tire last 4+ races instead of one, it would make economic sense. Ah well.

I dunno if the LF is limited, but it's largely a non issue. I ran the same tire for 8 or 9 races before it gave up, and then I think I finished the year with it on the LR. I think if I broke down the use I get out of them (not including punctures), it would be...
RF - 1 day
RR - 7 weeks
LF - 9 weeks
LR - 15 years

Guys in the next class up with unlimited camber might use 2 sets of tires a year. I went through 3 and the 4th is half gone. And their cars weight 3,400lbs while mine is but 2,100. Camber is king.