The Definitive Alignment Guide for your E36 M3

[ScotcH]

Good stuff. A few comments.


There is no such thing as "front body roll" vs. "rear body roll". The car is one piece - they roll together. Reducing total body roll will reduce understeer due to, as you point out, reduced positive camber in the front in turns (the fronts gain more positive camber in roll and lose more grip than the rears because of the McPherson struts)

HOWEVER, increasing only the front roll stiffness with just a bar tends to *increase* understeer if not for the reduced roll. The end result of whether you get more or less understeer depends on other factors such as tire characteristics and grip available.

So it is much better to upsize BOTH front and rear swaybars.

The is good in theory, however, it does not work in practice on the e36. Many race cars (including both of ours) run a big front bar, and NO REAR bar at all. The bigger front bar increases front grip, and the no rear bar keeps inner tires on the ground during cornering. It works. The big caveat here is that the suspension itself needs to be properly setup before this works ... usually the rear springs need to be stiffer than usual (we run 800 front, 950 rear, but that's probably a bit much in the front ... I'll be trying 700# this year).

Now for a street car, I would certainly recommend replacing both bars. The overall reduced body roll feels quite good for spirited driving.

As for the rest of the write-up: Bravo! Great info, and very accurate for anyone who wants a good alignment for the BMWs. Of course after a few track sessions the best way to tune alignment is by measuring tire temps, but the starting points you posted are excellent.

[BXMPWR]

What is the average cost for an alignment. What do you think is fair/reasonable. NYC area if that matters.

[JETninja]

$120......

[subrahman]

Wow - thanks for the writeup!. I started running (slowly) in STU in WDCR last year and am just starting to work on my car. Its hard to find all of this information in once place..

[kosta]

cool thanks

[Jason C SBB]

The is good in theory, however, it does not work in practice on the e36. Many race cars (including both of ours) run a big front bar, and NO REAR bar at all. The bigger front bar increases front grip, and the no rear bar keeps inner tires on the ground during cornering. It works. The big caveat here is that the suspension itself needs to be properly setup before this works ... usually the rear springs need to be stiffer than usual (we run 800 front, 950 rear, but that's probably a bit much in the front ... I'll be trying 700# this year).

Now for a street car, I would certainly recommend replacing both bars. The overall reduced body roll feels quite good for spirited driving.

As for the rest of the write-up: Bravo! Great info, and very accurate for anyone who wants a good alignment for the BMWs. Of course after a few track sessions the best way to tune alignment is by measuring tire temps, but the starting points you posted are excellent.

Fine, but there is still no such thing as "front body roll" vs. "rear body roll". Tuning with no rear swaybar works with stiff rear springs (as you pointed out), or with lots of front negative camber.

[ScotcH]

Fine, but there is still no such thing as "front body roll" vs. "rear body roll". Tuning with no rear swaybar works with stiff rear springs (as you pointed out), or with lots of front negative camber.

Yup ... we run -4 in the front As I pointed out, you are absolutely correct that eliminating roll is good, and beefing up both bars does that very well on a steret car.

[techron]

good stuff! thanks for the pointers on the alignment. I always wonder how much camber was too much for the street or canyon but i guess if you eliminate the toe up front ur good to go. I have been wanting to increase from 1.5 to 2.5 neg up front but my friends were saying it was to aggressive for DD. SCREW THEM lol...

[oraph]

nice write up

[Jason C SBB]

My gut feel is -2° is the max one might tolerate on the street....

[99E36M]

How much toe and camber would I gain after adding a .120" shim to each side? I know I should get an alignment after adding the shims but wonder how bad it would be...

[joenationwide]

My gut feel is -2° is the max one might tolerate on the street....

I know you are quite knowlegeable about suspension setup. I would believe -2 is max for a miata on the street. But I think you'll find the macstrut based bimmers really need at least -2.5 deg up front to get adequate front grip. Coupled with 0 toe there should not be significant inner tire wear.

How much toe and camber would I gain after adding a .120" shim to each side? I know I should get an alignment after adding the shims but wonder how bad it would be...

My guess is you'll gain approx -1.2 deg more camber. You'll also introduce some toe out (if you were originally at 0 toe). How much I'm not sure. I wouldn't suggest it is not insignificant. Certainly worth an alignment afterwards.

[JETninja]

My gut feel is -2° is the max one might tolerate on the street....

Did you read my Posts? (post #10)

-2.5 camber 0 toe Font
-1.5 camber 1/8th toe in Rear

I do 70m a day, almost 50k since I bought the car 3 years ago this month. I love this setup and have no plans to change it. Right now car is on stands as I replace all the outter rear ball joints, the rtabs and rear bearings, then it'll go in to EF1 in Long Beach for an alignment, to the same old specs.

[bmwpowere36m3]

I DD my car with:

Ride Height
Front: 13"
Rear: 11.75"

Alignment
Front Camber: -3.2
Front Toe (In): 1/16" Total
Rear Camber: -2.2
Rear Toe (In): 5/32" Total

No problems and handles great.

[chrisria]

You guys sound like your well versed on this subject:what specs for a completely stock ,street only,daily driver?

[sirius600]

I DD my car with:

Ride Height
Front: 13"
Rear: 11.75"

Alignment
Front Camber: -3.2
Front Toe (In): 1/16" Total
Rear Camber: -2.2
Rear Toe (In): 5/32" Total

No problems and handles great.

Hmm, how much does ride height affect the alignment settings you might go for?

[RRSperry]

I just got an alignment yesterday, after installing GC shims, and getting new tires. The old tires wore well, and evenly. Needless to say the rear toe and camber were a bit off.

I sat in the car during the alignment to act as the weight.

My suspension setup is H&R OE Sport springs, Koni inserts and shocks, UUC bars, (not that they make a difference. lol)

Front camber was -1.5 L, -1.7 R. 1/16" in, castor was fine.
Rear set to -2.5 L,R. 5/32 in total.

The rear before setting was -1.5L, -2.3R, and about 1/2" toe in...lol I guess I didn't get the RTAB consoles back where they started, but that is what alignment is for... It really didn't feel that bad driving to the shop.

Got charged a whopping $89. The guy that did it is a Multi time SCCA Regional Champion, (MARRS) in BMW 2002's, E36's, and Corvettes, so he knows these cars.

[savage217]

I DD my car with:

Ride Height
Front: 13"
Rear: 11.75"

Alignment
Front Camber: -3.2
Front Toe (In): 1/16" Total
Rear Camber: -2.2
Rear Toe (In): 5/32" Total

No problems and handles great.

What is 5/32 in degrees? I was suggested by many people to do 1/8 inch in. Not sure what that is in degrees. My rear camber is -2 and fron is-2.5, thanks.

[Patrón]

excellent thread, thanks for taking the time to put it together.

[bmwpowere36m3]

Hmm, how much does ride height affect the alignment settings you might go for?

Well in the front (w/o camber plates) you'll keep gaining negative camber to a point as you lower the ride height. However with camber plates its not an issue... currently I'm just running the OE strut mounts swapped with the GC CO's and that netted me -3.2 degrees camber up front. In the rear (w/o camber arms) again you'll gain negative camber as you lower and with the "stock" adjustment you *might* not be able to adjust all the negative camber gain you got. Also you limit the amount of toe-in, I believe, available as you lower it.

However, if you don't go to any extremes... you should be able to get a reasonable alignment. Note that I don't have any aftermarket "camber adjuster". I was able to achieve those numbers with the OE Strut mounts, OE camber arms, etc... Rear camber arms anyway are usually used to ADD negative camber out back, not take it out.

If I wanted less camber up front I would need to install camber plates, because even if I raised the ride height the camber wouldn't change a whole lot or I could "un-swap" the OE strut mounts.

[bmwpowere36m3]

What is 5/32 in degrees? I was suggested by many people to do 1/8 inch in. Not sure what that is in degrees. My rear camber is -2 and fron is-2.5, thanks.

The "toe" settings are in inches, so 1/8" ~ 5/32"

[sisomphonE]

explaination on caster?

[99MPower]

Front camber was -1.5 L, -1.7 R. 1/16" in, castor was fine.
Rear set to -2.5 L,R. 5/32 in total.

your camber settings should be reversed

I've found through a LOT of auto-x that anything more than -2.2 rear camber gets very tough to put the power down, even with a full soft rear sway, and -4 front camber, as I start oversteering, and the back wants to come around on me

side note for sway bar settings...

FULL stiff front sway bar
FULL soft rear sway bar

i run

street
-2.5F 0 toe max caster
-1.8R with 1/8" toe in

track
-3.5 1/16 toe out max caster (automatically toes out with camber change, PERFECT
-1.8R camber with 1/8" toe in

auto-x
-MAX front camber with 1/16 toe out (usually about -4.2 front camber for the plates)
-1.8R camber with 1/8" toe in

full stiff front sway
full soft rear sway

hope this helps

[bmwpowere36m3]

explanation on caster?

Castor, only applies to the front, is the angle the steering pivot axis is "tilted" from vertical. Its what pushes the wheel forward into the bumper of some M3s when people install mismatched LCA & LCABs. So they gain a lot of castor...

It allows straight-line "stability" and helps the wheel "gain" camber when turned, like going thru a turn.

Don't really worry about it, just try to maximize it (a high positive castor 7-8 degrees) Your limited in what you can adjust anyway with camber plates... Auto-x guys try to maximize camber at the expense of some castor and track guys don't need as much camber so they maximize castor.

[sisomphonE]

Castor, only applies to the front, is the angle the steering pivot axis is "tilted" from vertical. Its what pushes the wheel forward into the bumper of some M3s when people install mismatched LCA & LCABs. So they gain a lot of castor...

It allows straight-line "stability" and helps the wheel "gain" camber when turned, like going thru a turn.

Don't really worry about it, just try to maximize it (a high positive castor 7-8 degrees) Your limited in what you can adjust anyway with camber plates... Auto-x guys try to maximize camber at the expense of some castor and track guys don't need as much camber so they maximize castor.

sweet. thanks!