ZR1 track alignment tips
 

Hey guys,

I am looking for some suggestions from experienced users about how to adjust the suspension for track configuration. I can easily find the values for camber/caster/toe, but I wanted to know what exactly do people end up doing to achieve those values on a ZR1. I am getting conflicting stories. A friend with a GS tells me to remove the upper washers to get the camber close. The Owners manual says to NOT remove any washers if it's a ZR1... So here are the questions that i have:

1. For camber, can I achieve "-2*" of F/R camber with just the lower cam bolts? (moving the bottom of the wheel out is preferable over moving the top of the wheel inboard because of track width). Or do i have to remove one washer (or 2 washers) from the top control arm mounts?

2. For Caster: How do I adjust caster? Am I pretty much trying to move the lower control arm cam bolts in a "assymetrical" fashion to effectively move the lower ball joint forward or backward? Or do I "assymetrically" remove washers from each upper control arm to effectively move the upper ball joint?

3. For Toe: i see some videos for aftermarket toe arms. Can I still dial in the recommended .05* toe in with the -2* camber on OEM toe adjusters or do i need aftermarket?

4. For those who track the ZR1, what settings do you find work well on the track? Factory recommendation or otherwise? For example, my biggest fear with the ZR1 is that the rear will get loose in a turn.

Thanks guys

I don’t know the answers to your questions but curious as well. This will help move it to the top. Also, to whoever answers do you know if spring mountain runs the factory specs or the race specs?

Here is an alignment report off a ZR1 at SM. I don't know if they dropped the front ride height like the owners manual recommends for track use but these settings look a lot like the DSC Sport recommendations. I would remove the washers and you *may* need aftermarket rear toe arms but I did not.

https://cimg7.ibsrv.net/gimg/www.cor...30a136dd66.png

Search for Poor-sha on the Forum or HiPo Driver on Youtube. He had his ZR1 dialed in pretty good. According to the Owner's Manual you should be able to get to the recommended track alignment w/o removing shims from the ZR1 upper control arm (use the lower control arm cams). I think most people recommend replacing the cam bolts with aftermarket ones to prevent slippage. I doubt you need aftermarket to get the toe dialed in. For caster, do upper control arm adjustment. Track alignment is mostly a function of the track vs. street use of the car. If you're aligning strictly for the track you can fine tune it more for better tire wear and traction (-3 camber). I found track alignments make the car handle worse on the street (and wear out the inside of tires).

I saw Poor-sha already beat me to the punch. Do what he says. :)

@poor-sha thanks for that. When you said you would remove the washers, do you mean that it's optional? Can i still get my 2* of negative camber with the washers in?

@range96 thanks. For caster adjustment you mentioned adjusting upper arms. Can you elaborate on that? Is it by removing washers or something else.

I'm not sure on the washer question. You can either remove them and know it will work or try it first with the washers.

Each control arm attachment point has two bolts with washers. Remove one washer from each bolt on the upper control arm front leg to increase positive caster.

If you remove washers equally from both legs (4 bolts) from the upper control arm you will not change caster, you just increase negative camber.

Haha. You beat me to the punch again by a minute. I never see your post until I reply.

Thank you. this makes perfect sense (except for "increase the positive caster part"; i think you meant decrease..). But yes, this is how i thought that the caster is adjusted on the car. It seems like a very "granular" way of titrating caster tho.

Is caster something that is "in spec" from the factory (meaning that it is unlikely that I will have to asymmetrically remove washers from front vs rear legs of the control arms?

Also, do you guys know if the GM corner balances the car form the factory? My height adjustment bolts are not at all symmetrical from side to side.

You're absolutely correct, you ADD front shims only to increase positive caster (and marginally decrease negative camber). My bad, just ask Poor-sha. :)

Caster is probably in spec from factory, but I would check it. I saw some recommendation for +7.5 front, +.75 at the rear wheel. Owner's Manual recommends +7.0 front 0 at the rear for the track.

I don't know if factory corner balances or not. Mine sits 1/8" higher at the RR from the factory.

I wanted to lower the car a little and corner balance it. I dont want to lower it too much (just a tad more than the 12mm that factory bolts allow). Maybe like 1''. Do you guys know which lowering bolt kit holds up to the abuse best? I'm trying to research it but i cant seem to find the best lasting pad (i dont want the pad to wear and change the suspension setting). Ebay has them for $29. THey look similar to the 50-60$ that others are seliing. What do you guys think? Thanks

Ok, just ordered the weapon X swivel type bolt adjusters. Hopefully that will keep the pad from grinding thru. Can anyone comment of the quality of those adjusters?