Rear camber

[ps2375]

On an IRS rear, how do you adjust the camber. I've been looking at the Bently, and it says how to adjust Toe and center it, but no mention of the camber adjustment. I'm assuming it is not easily done, I've adjusted the front camber and installed a set of caster shims, And just thinking of what to do, if anything, with the rear.

The car is street driven and sees actual mountain roads and some auto-x's. It has front and rear sway bars and I just got a set of Bilstiens for the front and hope replace the KYB's in the rear with Bilstiens also. The car is a 69', so ball joint front and IRS rear and is at stock ride height, thinking of drop spindles for the front, but not set on those.

[Bruce.m]

Where the trailing arm bolts to the spring plate you can twist the mounting point clockwise/ anti-clockwise by a small amount and this changes the camber (limited amount). The 944 used a special bolt to make this adjustment. Kerscher sell this bolt (it is the anti roll bar bolt) but you have the open up the correct hole on the spring plate to a larger size.

[Dale M.]

Do not believe there is a true camber adjustment... Most trailing arm have a camber built in from factory and you are pretty well stuck with it unless you want to fab up a new mount on torsion bar housing or actually twist the trailing arm to change angle....

Dale

[ps2375]

OK, not an easy adjustment to make. I'll just have to stick with what it has already, luckily(most times) the majority of the weight is back there to aid traction/grip. I'll just have to balance front grip to the rear, and right now, the front needs much more help than the rear. I think I've helped it quite a bit, we'll see after the next event, but that is not for a month or so. Although on some twisty roads at moderate speeds it seems to have improved a good amount. But, I don't drive on public roads like I do on an auto-x course.

[PhillipM]

As above, all you can really get is what clearance is in the mounting point holes - slacken the various bolts, spring plate bolts, etc, twist it and torque 'em back up, will get you a little bit but not much.
For more you'd have to make new arms or move mountings (with the associated geo. changes), my new rear hubs bolt on with shims between them and the arm for exactly the reason of making easy camber/toe changes.

[Marc]

If the issue is too much negative camber, one solution is to swap control arms from side to side...stock, there's some negative camber "built-in", so when flipped you get more positive.
Of course, this entails trimming off the shock-mount pockets and welding them back on rightside-up, but I'd rather do that than heat & tweak the arms.
With the 4-bolt (dual springplate) setup this'll also require making new holes in the springplates for the fourth bolt...

[Steve Arndt]

Make sure your spring plate bushings are sound. If they are sagged out and old it will cause camber problems.

[ps2375]

I don't seem to positive camber at the rear, at least visually. I haven't had it on an alignment rack yet to get the actual numbers. The front has now been adjusted for some negative and hopefully that will help keep it negative under hard cornering, as I could see it going positive when my brother was driving it on course through a long sweeper.

[Steve Arndt]

Bad bushings will make them sag out and sit with negative camber. It also makes the toe in/out change when you get on the gas/brakes.

Is this Jeremy that I sold wheels to a couple months ago? My dad owns Wagon Works in Boise. Sorry if I'm mixed up.

[ps2375]

Bad bushings will make them sag out and sit with negative camber. It also makes the toe in/out change when you get on the gas/brakes.

Is this Jeremy that I sold wheels to a couple months ago? My dad owns Wagon Works in Boise. Sorry if I'm mixed up.

Nope, I am not him. His car is handling very well, I did a ride along on one of his runs, and I couldn't believe how much grip his car has with the tires (RS2's) as compared to mine. I have a new set of full treaded tires that are sporty but deff not semi-race like his.

The rear on mine looks like it is pretty well within stock spec's, no sag or anything. And no darting either direction on or off the gas.

[my69baja]

Pete!! Steve!! Whats up guys! This is Jeremy. Finally made a STF account. First, Steve, the wheels fit perfect. Sprayed them silver to somewhat match the rears.

Pete, as far as I know, the best way to adjust rear camber is lower the rear. Since you are running stock height tires, you might try to lower it just a bit. Not sure how low you can go without rubbing. When I first set up my rear end, it was way way to low but had crazy camber. I re-indexed the rear up about 3/4" so she didn't scrape on EVERYTHING but lost some camber. For reference, I'm currently sitting at -2.8° in the rear.

As Bruce said, tilting the trailing arm assembly cw/ccw does adjust camber a bit. When it got lifted back up, I played with a cheap harbor freight magnetic dial guage so see the change in camber. From memory, the guage showed almost a degree difference. Took some pictures for reference later but ended up deleting them had too many pics on my phone and needed to clear out the junk.

If you need a hand/space, I have all the tools necessary and garage space to work. The Bilstein shocks might help with front grip. Help keep the back from squatting causing the front to lift. I've got KYBs now and would like to go stiffer. Maybe slightly stiffer torsion bars to help reduce squat on launch/tight corners. At the autocross we ran together, I had 3/4"bars front and rear. It was lifting the inside front tire really bad. For the hillclimb, put on the 12mm front bar and it felt more planted. We will see if it works on the tight auto x course.

Are you planning to run this weekend?

Jeremy

[my69baja]

They are Hancook Ventus RS3s btw. Have heard really good things about the Hancook V12s. Plenty of grip but more suitable for daily driving. There were a couple people at the hillclimb running them. TireRack is the place to go for cheap prices

[Steve Arndt]

Nice to see you here Jeremy.
Make a build / project thread for your car and racing endeavors.

I have a set of almost new rear IRS Bilstein shocks and complete 944 rear suspension for sale to any local racers.

[ps2375]

Are you planning to run this weekend?

Yes, I'll be there on Sunday.



I have installed the Bilstiens up front, added a caster shim and adjusted the front camber and installed the rear bar. On my drives on Dry Creek Rd and up to Bogus, the car is much more planted and the front bites way better.

[RHough]

I've been searching for details on the rear camber and toe adjustments on my Ghia for hours.

I assume getting the toe and the thrust line right is job one, then where/what/how do you set camber? 90% of the links I find are for lowered cars. I just want to set ride height and do a nice square four wheel alignment.

Speaking of ride height. What is it and where is it measured?

Cheers,
Randy