Alignment specs

#1

Hey guys, would appreciate advice on setup. I recently took car for alignment analysis. Here are the numbers. I did not have them make any adjustments yet. Wanted some input. I’m a noob at this aspect. Which ones need adjusted; how much. I did read the post about rear camber & toe. Is it out enough that I should go to eccentric RTABs.
thanx,
tom

Front left camber -2.7° Front right camber -3.0°
Front cross camber 0.2°
Front left caster 8.6° Front right caster 8.5°
Front cross caster 0.2°
Front left toe .10° Front right toe .12°
Front total toe .22°
Rear left camber -2.3° Rear right camber -2.0°
Rear cross camber -0.3°
Rear left toe -0.11° Rear right toe 0.01°
Rear total toe -0.10°
Thrust angle -0.06°

#2

The front isn’t bad but I have to say I do not like the rear. I am assuming that the rear is toed out because of the negative (-) symbol in front of the number. The toe numbers look like they might have been measured in inches not degrees but I could be wrong. I am new to spec e30 but I do have experience setting up bmw suspensions for track. I have an e30 and an 36 track car. This is just my somewhat educated opinion on the subject and you will get a lot of different feedback the more you ask. But here it goes;

This is a very condensed version of alignment angles. Alignments are very specific to driving style. Your camber all the way around looks good, 3-3.5 degrees negative up front is probably ideal as is 2-2.5 negative in the rear. The toe is what really differs with different driving styles. Front toe is easy, usually people like 0 toe up front to not scrub off any straight line speed but a little front toe out (negative number on most alignment machines) does help a little with turn in (about -0.03 to -0.06 in per side). Rear toe is more important to me. I like to set up my cars with a little more toe in. About 0.09in per side. I do this because it helps the car be more predictable and stable when the rear end gets loose. Some people who have very good car control might opt for less rear toe or even no rear toe (0in).General rule of thumb; toe out in the rear will make a car more prone to oversteer, toe in will make the car easier to steer once oversteer is induced.

Please take this advice with a grain of salt. This is just my opinion. You will probably get many people who will recommend different settings. I am trying to help but my driving style my differ from yours. If you have anymore questions please feel free to ask.

#3

Tom, I agree with Antz it is all good advice. Get the rear toe fixed either through an eccentric bushing or if necessary make sure nothing is bent. My right rear was badly toe’d out and I had to get it straightened at the frame shop. It was a bit of handful with the toe out especially in high speed corners.

#4

From the look for the specs. I do not think that anything is bent. It is very common for an e30 to have toe out in the rear after being lowered. The fact that both sides are very similar is also a good sign. The adjustable bushings from AKG motorsports are very nice. You can never rule out bent components especially in a race car, but I would try the adjustable bushings first.

#5

Many thanx. Exactly the type of info I was hoping for.
Dumb question - what should be the orientation of the eccentric RTABs to achieve less negative toe on the left rear? Note that the right rear is a positive .01°. Is this OK? And yes, the printout had degree ° symbols, and not inches.
Also, since you say neutral or slight toe out is optimal for the front, do you think I should get that changed since it is slightly toed in?
thanx again,
tom

#6

tomzzy wrote:

[quote]Dumb question - what should be the orientation of the eccentric RTABs to achieve less negative toe on the left rear?
[/quote]

Don’t know

tomzzy wrote:

[quote]
Also, since you say neutral or slight toe out is optimal for the front, do you think I should get that changed since it is slightly toed in? [/quote]

Yes

#7

tomzzy wrote:

http://e30m3performance.com/tech_articles/susp-tech/ecc_bush/ecc_bush.htm

Check out the graph on page 4.

#8

Elephant4 is correct, get the front toe changed as well. I would recommend 0 toe up front since you had toe in before. If you go with the AKG adjustable bushings then there is only one way to install them. They also give you a certain range of adjustment from where the car currently is, so you should have no problem getting less toe out and hopefully some toe in.

As far as the angles measured in degrees, I measure toe in inches when doing alignments so those are the specs. I know. You can either ask you alignment person to do the same or trust that they know how to convert the angle to inches for you. If they are using a computerized machine they should be able to change the specs to read toe in inches.

My friend Sean just installed a whole bunch of parts including those adjustable trailing arm bushings on his car and has a tread up about it on a local bimmer website.
http://www.baybimmerz.net/forums/showthread.php?t=1258

I hope this helps.

#9

OK, I’m starting to figure out that camber up front should be about -3deg. and toe ZERO.

…and for the rear, -2 to -3deg camber…

For us “string alignment” types, what kind of toe in are we looking for in the rear? …in mm.

I use 2mm IN per side on my 911 and it works well…what should I shoot for in the E30?

Also, not much talk about CASTER settings up front, my general rule is to keep the #s somewhat even, my 911 has 6.5 left and 6.25 right so I left it alone…again, what should I shoot for on the E30?

Thanks in advance for any help.