Downforce and alignment

[AlleyCat]

So at the big end of the track my car will head a little to the right. The mechanic states the alignment is fine for a daily driver. But when simulated with down force the alignment changes. Does that make sense? So he wanted to know if I wanted it aligned as a daily driver or for the quarter? If for the quarter the specs would be out of alignment for a daily driver.

 

[DavidKFla]

what's the main use?

 

[AlleyCat]

Street. But a little scary at 145 correcting to left with front runners.

 

[DavidKFla]

it can get sketchy

 

[DGatzby]

I use the same alignment on the street and up to170 mph on road courses. Never pulls and never heard of that.

Downforce? Ha, you got a big wing that rolls force to one side? Otherwise overall downforce IF the Challenger has any would be across both wheels so why would it pull one way anyway?

Goofy, check your base alignment.

 

[AlleyCat]

Will get and print out for you in a few hours.

 

[Marc W]

The “road” alignment is to account for crown in the road that is there for water runoff. “Track” is for a flat surface. Split the difference and see if it changes enough to tell on either. The biggest factor for stability in a straight line is going to be toe. It needs to be “in” and critical that they are very close to the same on both fronts. Any toe out on one side or the other will steer the car in that direction. Of coarse the guy should know all that. The only change in alignment numbers that should change with downforce would be camber. That shouldn’t matter in a straight line. If he thinks that could be an issue then I would consider getting a second opinion. You’re talking a real alignment rack being used. Right? Also…. Frontrunners are super straight line stable. I’ve gone over 185 on mine and that’s about a hundred mph faster than 145. 😂

 

[AlleyCat]

I assume so. So on the aad fronts have toes in and equal to each other. What value should I have them put at?

 

[AlleyCat]

Spoke to Zach at AAD. He said the front AAD arms do not influence toe. Factory parts do. He actually is in Phoenix and has a shop. I am going to make an appointment with him and drive the car to his shop.

 

[jroyk]

Might want to try a different shop. Years ago, my dealership's rack was out of wack. The printout showed everything was green but the car still lead right. Took it to my favorite tire store... their printout showed a lot of red.

Also, since these aren't F1 cars, I would think the problem would be lift more than downforce at high speed.