Finally Got Alignment - Yikes
 

I guess no matter how gently you think that off-track ride went, the alignment needs to be checked.

One rear tire went to -2.3°, the other at the correct position of -0.7°. Total rear toe was -9/32".

Front camber went to -1.5°, the other at the correct position of -0.9°.

I wimped out and only went to -1.7° on the front and -1° rear camber. Front and rear toe both at 0°

Front caster was at 7.5° but the bump steer seemed excessive. I had them drop the caster down to 7° and that really seemed to improve the bump steer.

Did I screw up by having the caster set that low? Thats about the middle of the stock alignment range.

So, who's bump steer kit should I get? The guy at the shop also suggested getting rid of the camber eccentrics and using one of the "stepped bolt" kits. Guess I'll have to search the forum on those.

Four weeks until I can check out the alignment at my next track day. Hopefully going from -0.7 to -1.7 front camber will be something I can feel.

"stepped bolt" kits, aka camber plates. Afe makes them, and there is another but the name escapes me at the moment.

At then end of the day during my first track day experience, the right rear camber adjuster let go in mid turn, high speed sweeper. I changed to camber plates before my next event.

Not all shops know how to install them, I've trained three so far and every time I go back for a check/adjustment, I get a new tech to train plus you get to pay for their training...

I run 6.5 degrees of caster without any problems, prior to that it was 7.5 and while I didn't really notice a difference on the track my power steering seems happier with the change.

I just installed the aFe/Pfadt camber kit on my car, haven't tested it out yet but have had minor camber changes occur in the past during track events with the factory eccentrics.

Regarding your current alignment specs, that's pretty close to what I adjusted mine to. From my last track outing I needed a bit more camber as I was rolling the tire over a bit too much onto the shoulder. Hopefully these settings will work for both of us.

I can't comment on the bump steer however as I haven't gotten that far into dialing everything in.

Since cams can and will move, I always use a paint pen to mark the cams, bolts or anything else that should not move but might so I can instantly tell if something has slipped. Yellow color works great so you can instantly tell if everything is still in place after the alignment.

I promise your alignment guy didn't check the bump steer.

Yea, that's something that takes a lot of time to do, pretty involved considering what you have to disconnect.

And alignment racks aren't set up to check it.

I can't even get under the car far enough to mark the front cams without raising the car. Then they aren't in the right position to mark them.

Someone please tell my wife I need a four post lift.

Your cams don't move when the car is raised. If they do then you're in trouble.

I'll be posting up in a couple weeks with my Be All and End All camber plate kit. I've had less time to make product this season than I would have liked but I'll have a window opening after NASA Nationals next week.

If torqued properly eccentrics don't move. I would go a minimum of -2.2 front and -1.2 in the rear with 0 toe. Your caster should be even on both sides 6.5 - 7.5. You can check the bump steer on the alignment rack by pulling the suspension down with a come along. I prefer doing it with a dial indicator and it is time consuming to get it right.

Something is moving when it's raised. All the factory marks on the cams do not align when it's off the ground. When placed back down, the marks align again.

Those cams are to adjust the lower control arms inward or outward on the car. The bolts should have 130lbs of torque on them. If your cams are moving when you lift the car then your bolts are extremely loose. I think it would be pretty obvious when driving the car that you had a major problem.

My fault for not fully explaining.

While adjusting the front settings (first caster, then camber, then toe, then camber, then toe) the toe seemed to be drifting around (but equal on both sides). I was looking at the rack to see if it was loose or the rod ends or some other suspension part had play but couldn't find anything. Then we noticed that simply pulling down (my body weight) on the nose of the car and it would change the toe. Similar (but checked to a much lesser extent) to what sccaGT1racer mentions, but we weren't looking to do a complete bump steer check.

Performing the same non-calibrated check with less caster resulted in less toe change.

The car is a 2000 Z51 (I'm original owner) with T1 bars and 29k mi. I haven't changed ride height but think it is lower in the front than when new as my floor jack no longer is an easy fit under the jacking pucks.

Mike, thanks for letting me know they're called camber plates! When I had read camber plate in previous posts, I pictured (without thinking) the camber plates I used on the Rx7 strut suspension. Those are large plates w/bearing, shock mount, and indexed slots. I'll be interested in StreetSpeeds write up!

Mongo, I'll let you know how it works next month!

sccaGT1, yup I wimped out. It had been suggested in a previous thread that even with it being a street / track car with NT01's, my ridiculously low annual mileage (~2k / year) would allow me to run at a full race alignment. I would not be surprised if I end up at something close to what you suggest.

Thanks!

Is there a risk of the bolts spinning if I get under the car and check the torque?

Checking bump steer is a huge deal. It usually takes a race shop to do it.

Do not install one of the kits until you have it checked. Some race teams have found that the kits create bump steer problems. Measure first. You may not need a kit.

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Richard Newton
Historic Racing Images

Certainly a risk as 125-130 ft. lbs is a pretty strong pull. I would check though. Mark the positions of the eccentrics to the subframe and counter hold the other end of the bolt before you start pulling.

Torque was a touch low on the eccentrics but now are all up to spec (125 up front, 71 / 107 in the back).

I checked the ride height and the car is low, and different left / right. I measured the distance specified in the manual from the wheel centerline and up to the lower edge of the fiberglass rocker (is that the right place). Stock should be 6" front and 6.2 back. I got Front Left = 4.5, Front Right = 4.75, Back Left = 4.75 Back Right = 5". The stagger looks right but the car is low and tilting down to the drivers side. Doesn't seem right that its that far off. Tire diameter calculate to be very close to the stock (non Z) oem size.

Guess that means I'll need to get on some scales to set the corner weights / height.

Also noticed paint scraped off the front swaybar (T1) on the drivers side from contact with the lower control arm. Don't know how that happened so I adjusted the end links for more clearance.

Lastly, noticed this bolt seems to have more threads exposed (again on the drivers side). I'm guessing its the height adjusting bolt. I don't know whats under the spring, could something have broken under there or maybe it has been slowly backing itself out.

Today I spun the front adjusters until they touched the top keepers (four full turns). That only got the front up to 5.25". Thats still 3/4" lower than listed in the service manual. There's no way I can get it back to that height.

Are the bumpers between the adjuster and spring a wear item? It looks like its intact but maybe its compressed?

Any idea whos got the best price on the aFe camber plate kit?

Vansteel in FL, Ecklers also carries vansteel camber kits.
Just looked, and vansteel's site is down for maintenance.
Hardbar used to get some of his parts fron vansteel, and I think he sold some of his designs to them when he went out of business.

West Coast Corvettes has the best price I can find at $350 for the aFe's.

How soon do you need the camber kit? I'll have our kit available soon which will be the Last Word in adjustability and there's no way I could charge $350 for them and look myself in the mirror.

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