suggestions on rear camber setting

[91Saleen#15]

I'm running an 89 325is with an S52 conversion. On the fronts I have 285x18 hoosier a6's. On the rear I have 315x18s. shocks are dual adjustable Konis. Any ideas on rear camber setting will be appreciated.

[RoccoB517]

Granted I run 225/45-15's but here are my alignment specs for your reference:

Front:
3.5 Degrees camber
0 Toe
9.75 Caster

Rear:
2.5 Degrees Camber
1/8" Toe In

I run 800# rear springs and 600# front with Koni single adjustables set at full stiff in front and 2 turns off of full soft in rear (exactly middle setting between soft and hard). I also have no rear sway. Ride height is maxed out low in rear (GC coils) and 1" below max height in front.

I've had great success with this setup on the track. For autoX I'd start by suggesting some toe out in the front, and possibly going to zero toe in the rear.

Hope this is of some help.

[Chris916]

^That's a very good starting point. I'd suggest about 3/16" out in the front. It will help your turn in quite a bit. However, if it's mainly a street car, that may be a bit too much.

I also run about 4 degrees of camber up front and tire wear/temps are bang on.

[91Saleen#15]

How much power do your engines have?

[RoccoB517]

Around 220 at the wheels. Car weighs about 2500 lbs.

[RoccoB517]

I also run about 4 degrees of camber up front and tire wear/temps are bang on.

Yeah, the difference between 3.5 being awesome and wanting 4 degrees is very dependent on the track. Honestly, I feel like 4 would be better for AutoX. However, one rule of thumb that always seems to pan out for me is 1 degree difference between front and rear. That seems to keep the car very balanced.

[Chris916]

Yup and it's all about driving style and comfort as well. You need to play around with what works for YOU best.

I run a stock s52 so probably around 220 at the wheels as well. The car is 2300lbs dry. I'm also on 255's so not quite as large as you lol

[TobyB]

One other thing that will affect the camber is the tire fit on the rim. If it's squeezed or stretched, that chages things. Coming from the old ITB world with narrow rims, I found
we used more negative camber than anyone else simply because the damned tire moved
around so much. Going to a wider rim reduced the need for static camber significantly.
Also, tire sidewall height affects it, too... taller seems to want more.

t

[91Saleen#15]

Here is an update:

I went to from 3 degrees to 1 degree camber in the rear and feel that the car's handling is much improved. I find that I can get away with being more "ham-fisted" with the throttle. Before if I wasn't very, very careful getting back on the throttle after a corner, the car would break loose and get tail happy. The car seems to be much more forgiving now.

[TobyB]

You took camber OUT? As in, stood the tires PP?


t

[91Saleen#15]

You took camber OUT? As in, stood the tires PP?


t

Right... the car was holding corners great with 3 degrees, but the contact area in the rear was too small and the engine was overpowering the wheels and breaking loose. A better driver might have been able to be quicker in the car by handling the throttle better, but having more traction in the rear works better for me.

[Madhatter]

I once told people to run the front toed out and reduce the rear camber and people thought I was some crazy fool.

I have never found a lot of negative camber in the rear to be an advantage in most rwd cars with any moderate amount of power. The 1 degree rule is a good start point, but I've found suspension setup and tyre choice makes a huge difference and you can pretty well throw that rule out the window a lot of the time.

A lot of the E30's I've seen are run way too stiff (the rear in particular). If you turn up with 700+lb springs, rock hard dampers and the biggest bar you can find, im not really surprised it's a little twitchy and unsettled over bumps. If you take a temp probe and have a look at their tyres when they come in, you can really see where it's riding. Bit strange when you have all that rubber to help with grip levels and you only spend the majority of the time on 1/3rd of it.

[91Saleen#15]

I once told people to run the front toed out and reduce the rear camber and people thought I was some crazy fool.

I have never found a lot of negative camber in the rear to be an advantage in most rwd cars with any moderate amount of power. The 1 degree rule is a good start point, but I've found suspension setup and tyre choice makes a huge difference and you can pretty well throw that rule out the window a lot of the time.

A lot of the E30's I've seen are run way too stiff (the rear in particular). If you turn up with 700+lb springs, rock hard dampers and the biggest bar you can find, im not really surprised it's a little twitchy and unsettled over bumps. If you take a temp probe and have a look at their tyres when they come in, you can really see where it's riding. Bit strange when you have all that rubber to help with grip levels and you only spend the majority of the time on 1/3rd of it.

I think you're right. I didn't notice any problem with bumps, but the car was easy to get loose if you came onto the throttle too hard after a corner. I tried a few times to feed the throttle in with better touch and was able to control the breaking loose, but overall I was slower than when I came on harder and broke loose half the time.

I haven't been able to tell whether I have to hold less speed in the sweepers. It seems pretty much the same, but my shifts to second gear seem to unsettle the chassis less than they used to. I used to have to be careful about shifting while turning, but it's less of a problem now.


I'm running 800 lb springs in the rear, but shock settings are full soft. The rear sway bar is not excessively large and I've toyed with unhooking it completely. Right now I have it on the weakest setting.

The car in my signature is not the car I am running now. The current car sits quite a bit lower because I have trimmed the fender flares off both front and rear. This car is converted to 5 lug and running ten and a half inch wide 18 inch corvette speedlines. The tires are currently 315s in the rear and 295s in the front. I just bought a new set of Hoosier A6s that are 275/30R17s front and rear. I'm looking forward to see how they run.