Another alignment question for front m3 arms

[Jez]

Firstly an apology, because this question has been asked over and over..and it's got to be more frustrating for the people answering it than for the people asking.

It seems the problem is that there are no "ideal alignment" settings. It depends on a few factors:

1. How you drive it
2. If you track it
3. If you've pulled the cambin pins out
4. If you have front camber plates
5. If you have any rear suspension mods

I'm about to fit the following on my E82 135i:

-Front M3 arms (wishbones and tension arms)
-Bilstein B12 kit, which has eibach springs and lowers the car about 20mm

What I'm hoping for here, is some suggested alignment figures for my car and my driving style.

1. I drive spiritedly on the roads...there are lots of windy roads around me and I'd like the car to have a good turn-in feel. But at the same time, I do a fair amount of motorway driving (straight roads).
2. I do not track the car, this is my daily driver
3. Yes, I plan on removing the camber pins
4. No, I will not have camber plates
5. No, the rear will be stock

When my car is slightly lowered and has the front m3 arms, people say any of the following:

-Align to standard E82 specs
-Align to M3 spec
-"Invent your own!"

Please can some of the knowledgable people on here provide suggestions on what may be best for my situation and driving style?

Many thanks,

Jez

[John_01]

Adding a little bit of front camber will make a nice improvement in handling. You can reduce the front toe-in to make the car feel more agile. Too much front toe-in basically kills steering feel and handling ability.

For the rear toe and camber, the stock setting is fine. The trouble is that it keeps going out of spec. The rear subframe is easily affected by bumps and knocks. Also the stock rear subframe bushings are too soft so the subframe isn't adequately located and it moves around in normal driving situations. If you want an accurate alignment you should upgrade the rear subframe bushings to M3 items or similar, and also get the alignment adjusted about once a year.

[Jez]

Hi John, thanks for your reply. What I'm really hoping for is some specs to give to a garage when getting the alignment done.

So perhaps so far, the suggestion might be:

Front
Camber - Max possible? (with front m3 arms and pins pulled out) - Maybe -1.5 degrees
Toe - ?

Rear
Camber - Stock
Toe - Stock

I'm eventually planning on fitting an M3 subframe but for now leaving the rear standard.

Thanks

[dtla1]

Front:
Camber-Max
Toe-0

Rear:
Camber- about .2-.4* less than the front
Toe- anywhere from 1/16 to 1/8 total (of an inch)

[John_01]

1.5 degrees front camber is quite generous already. Around 1.0 degree would be plenty for usage on public roads. Minimum toe-in spec for the front is normally around 0.1 degree per side. IMO, 0.05 per side would be a better idea. Zero front toe will also be perfectly fine too. 0.15 degree per side is the maximum of the adjustment range and that isn't what you want for good handling. I would ask for an adjustment range for front toe between 0.0 and 0.1 degree total toe (0.0 to 0.05 per side).

Rear toe is normally around 0.3 degrees total toe (0.15 degree per side).
Rear camber is normally around 1.7 to 1.8 degrees.

[dbronnik]

My preference for how you drive your car and your mods would be max camber and 0 toe in the front.

If you want the steering to be more responsive then you can add some toe out in the front (I run 0.05 toe in the front).

[MightyMouseTech]

Well, your front camber will be whatever you get with the mods, just push in as far as it will go when installing the struts.

Set your front toe to zero.

In the rear, just set it to stock.

Enjoy!

[Jez]

Thanks for your help everyone.

I'm probably overthinking this but would like to try to get it right the first time.

I've collated everyone's views. I'm not trying to start any kind of debate, but thought it would help clarify and then I can make an informed decision.

-All figures are in degrees unless given a " for inches
-I think I've got the conversion from inches to degrees correct



My questions are:

1. dtla - when you said 0.2 to 0.4 less camber on the rear than the front, did you actually mean less? ie. more negative camber, so I should have put -1.7 to -1.9 for the rears?

2. dbronnik - did you mean toe out or toe in?

3. Does anyone know the oem/stock alignment specs for the rear camber and toe? It's not easy to find online for the E82.
E92 on 18" wheels is Camber -1.3 to -1.8 and Toe 0.10 to 0.20 which can't be far off though.


Thanks again.

[135TX]

See signature for mods but this is my alignment sheet done at a performance shop.
I have dinan camber plates and alignment pins pulled, are roughly my differences from your setup.

Frankly go as negative as you can up front if you drive spirited tire wear won't be an issue.

[John_01]

I think all the comments in the thread so far are in pretty close agreement. You could take an average or choose any of them and you will be fine. However the rear subframe bushings are the piece of the puzzle that is missing. You will like it even more if you go ahead with the M3 rear end swap that you mentioned.

[MightyMouseTech]

The front camber really is the limiting factor. Until you are able to get to -3.0 or -4.0 for track use just enjoy what you have.

[dtla1]

I meant what you have in the table there. And yeah, I think we are mostly in agreement here.

[Jez]

Thanks again for your responses. A few more questions:

135TX, thanks for posting that, it's really heplful and shows I'm doing in the right direction.

1. John, are you suggesting toe out on the front? (ie. negative toe, like 135TX's settings). I currently have it listed as positive toe, but think you may have meant toe out for better cornering?

2. What effect does rear camber have? dtla, is there any reason you're recommending slightly less negative camber on the rear?

Thanks again guys

[dtla1]

Rear negative camber helps with grip around a corner and will in turn provide more even tire wear.

[dbronnik]

Originally Posted by Jez

2. dbronnik - did you mean toe out or toe in?

Toe out

[TheBreeze]

I've been running 1/16 toe-out front and 1/16 toe-in rear for the past 3 years and have really enjoyed the result. Nice turn-in but still stable in a straight line. I run -2 camber all around, though I've been toying with the idea of reducing rear camber to -1.5 or so. I run Michelin PSS tires, just replaced to a new set. Got 15k out of the set, and still had maybe a 1-2 k of life left. The rears wore completely even all the way across, while the fronts had all kinds of rubber left but wore more on the inside.

[Jez]

Thanks for your help everyone, I'm almost there but can't decide on front toe.

Here's where I am:

Front
Camber: max, ie. -1.5
Toe: Really not sure. Very few people seem to run toe out, or negative toe. However...in some places I'm seeing recommendations of up to -0.28 degrees of toe out on either side... (which equates to 1/4", stated in this thread: http://www.1addicts.com/forums/showthread.php?t=576477)

M3 OE spec is a small amount of positive toe, something like +0.02 to +0.15 on either side. There's a lot of conflicting advice around on toe in/toe out and the amount to have. Should I just specify M3 spec for reasonable wear, handling, straight line stability, etc?

Rear
Camber: -1.7 to -1.8 (M3 spec has greater rear negative camber than the front)
Toe: +0.1 to +0.2 (about M3 spec and general consensus)

Tempted to go for an alignment and just say E82 spec with max front camber or M3 spec with max front camber and both will probably be about the same.

Only question really is front toe in or out. If I go for toe in then I'll just ask for an M3 spec to avoid the hassle of questions from the techs about why I'm requesting special settings.

Again, thanks for your help. Probably overthinking this, but a search shows I'm not alone!

[dtla1]

Remember that asking for a particular car's specs actually allows for a range, which is usually pretty large, to be applied. See the member above's photo of their alignment results and you can see the specified range listed above the actual.

[John_01]

IMO, slight toe in or close to zero toe is a logical choice for a new suspension upgrade. Apart from that, I don't think that toe out makes much sense for a car that is only used on public roads. You can do it, but it will make the car feel a bit twitchy and affect tire wear. IMO It would be better to wait until you finalised the rear suspension upgrade. I track my car and I'm personally not a fan of front toe out. I'm not saying it bad or wrong as other people like it. I'm just saying you don't need it on a dedicated road car, especially if you are still playing around with other suspension changes.

[Jez]

Thanks everyone, and yes you're right dtla, there is quite a large scope for variation if I just specify M3 spec, which is a good reason to narrow the bands a little.

I think I'm going to go with the following:

Front Camber -1.5 or max negative
Toe +0.03 to +0.08 each side (Decided I want slight toe in for better stability during motorway/straight line driving, and more in line with M3 spec)

Rear Camber -1.7 to -1.8 (M3 spec, about average)
Toe +0.05 to +0.1 each side (M3 spec is supposedly +0.025 to +0.075 on either side according to http://forums.m3cutters.co.uk/showthread.php?p=1032861)

Could increase toe in a little but should probably stop worrying about it no ha.

Thanks again for your help everyone.

[MightyMouseTech]

Here is my current alignment.

Have M3 front arms and Dinan plates. The rear I am using middle of the range for the 1M.

[dbronnik]

Originally Posted by John_01

IMO, slight toe in or close to zero toe is a logical choice for a new suspension upgrade. Apart from that, I don't think that toe out makes much sense for a car that is only used on public roads. You can do it, but it will make the car feel a bit twitchy and affect tire wear. IMO It would be better to wait until you finalised the rear suspension upgrade. I track my car and I'm personally not a fan of front toe out. I'm not saying it bad or wrong as other people like it. I'm just saying you don't need it on a dedicated road car, especially if you are still playing around with other suspension changes.

Have you personally tried running 0.05 toe out?

I run 0.05 toe out and I wouldn't call it twitchy at all, but it does help the car with turn-in (as compared to 0 toe), which is why I recommend it for the OP's purposes. I wouldn't recommend anything more than 0.05 toe out for daily driving though.

I do agree that it's best to leave this fine tuning until you've finished with other planned suspension upgrades to help isolate variables.