Race suspension alignment

[Brad Roberts]

Most folks do not use rear adj LCA's

I use them on every car every time.. It settles down the toe gain under braking by replacing those worn out rubber bits on our donor cars

FYI:

Unless you perform tire temps.. on your car.. at the track.. camber settings are *only* guesses. I have drivers that heat their tires evenly with -3.6 on a shaved RA1, then I have guy's who heat the tires evenly with -3.2 on the same tire.

Camber is driver and track dependent. I don't run the same camber on the right rear at Willow Springs that I would run at CA. Speedway. The track design heats the tire differently. You see this in pressures also. You cannot run the same cold starting pressure in the left rear at WSIR as the right rear. You will burn down the left rear

All good info coming from group!! The toe gain explanation is one of the best I have seen online!!

Also: Raising the steering rack in the front to correct bump = we've been doing this for years in 914's and 911's. Porsche Motorsports does this on ALL the RSR's and I do it on Cayman's and Boxster's

[LAP1DOUG]

Originally Posted by Brad Roberts

Raising the steering rack in the front to correct bump = we've been doing this for years in 914's and 911's. Porsche Motorsports does this on ALL the RSR's and I do it on Cayman's and Boxster's

This statement has been bothering me a bit. So, yesterday I checked my front bump steer. My set-up has aftermarket tie-rods, so I can shim the rod end at the upright rather than shimming the steering rack, but it's all the same.

My toe change was less than 0.1 degrees throughout the whole travel range with no shim adjustment. I haven't compared the tie-rods I am using to the OEM tie-rod dimensions, so it could be some difference there. The only other thing I can think of is that I am using a lot less caster than stock, so perhaps the caster change also has an effect.

I guess the moral is there is no short-cut to testing your exact configuration.