unvc92camarors

hey, i noticed someone said drag racers usually go on the 3" slot on lca reloc. brackets since they want the most push to the ground (understandable)
but autox'ers are said to use them to be parallel to the ground
why is that?
like why would you want it on a 2" hole instead of 3" when a 3" placement could probably get you out of a turn quicker?

Norm Peterson

Two reasons.

First, your rear axle steers slightly as the car rolls in a turn, aka roll steer. It's not under the direct control via your steering wheel, as it changes as the amount of roll angle changes (you sort of sit and wait for it to catch up). With the LCA's pointing downward from the chassis to the axle pivot, this steer effect will make the tail run wide. "Loose steer", as the circle track guys would say, describes the way this feels this quite accurately. While you can probably handle a tiny bit of this, too much is, well, too much. Translation: "spin", or at least "slow", and you wouldn't be able make up the time lost on corner exit. Never mind that coming off the corners harder won't happen if you're still busy gathering it back up under control or waiting for the axle to get pointed out of its tail - out (wrong) attitude. The consensus is that the bottom hole is too much, and level LCA's is the best "set it and forget it" solution for all cornering needs, based on the experiences of many.

The second is more directed at hard braking in LS-1 cars with ABS, though a really bad combination of several things could conceivably make this apply to earlier cars as well. Too much LCA angle = too much anti-lift = brake hop. Think of anti-lift as the evil cousin of anti-squat, and know that with most rear suspension arrangements if you get more of one, you get more of both.

Norm

unvc92camarors

thanks for the answer
i can sort of picture what you're saying with it feeling loose
looks like i'll set it level

didn't know about the ls1 thing though
interesting

Ken S

yea, thats why people try putting more aggressive compounds up front, to attempt to shift the brake bias up front, in hopes of reducing the axle hop when braking out back..

unvc92camarors

do you know if the ls1 cars had better brakes in the back (better than the lt1 cars) as well?
i know they had some awesome front brakes (compared to the lt1's)so i wouldn't think they'd havethat much axle hop