Need Alignment Spec recommendation

[sprp85]

Hi all,

I've recently finished installing Dinan plates and M3 front bits.

Now, I did the 3.5 turn method on the tie-rods to get it at least drivable.

As the above method was temporary, I am looking to get some recommendations on alignment spec.

The car is 128i.

Goal: Aggressive daily & occasional HPDE
Setup: Bilstein B12, full M3 front bits, Dinan camber plates.

(Rear is staying stock for now)

Of course, I will state "Max camber please!" but am kind of lost in terms of F&R toe + rear camber.

I've seen recommendations from 0 toe up front, slight toe in rear... to slight toe-out front, slight toe-in rear, etc...

I would love to get some ideas so I can get it aligned ASAP!

Thank you very much in advance,

[jcrane82]

All depends on how you want the car to feel. I personally like a car that rotates easily, so I will run zero toe in the rear and zero (or slightly toe out) in the front.

The handling balance is defined by all parts of the system:
-front/rear spring rates
-front-rear roll stiffness
-front/rear camber
-front/rear toe
-front/rear tire pressures

I would also not suggest "max camber". Max rear camber will induce major understeer, and not help the car to rotate.

[sprp85]

Originally Posted by jcrane82

All depends on how you want the car to feel. I personally like a car that rotates easily, so I will run zero toe in the rear and zero (or slightly toe out) in the front.

The handling balance is defined by all parts of the system:
-front/rear spring rates
-front-rear roll stiffness
-front/rear camber
-front/rear toe
-front/rear tire pressures

I would also not suggest "max camber". Max rear camber will induce major understeer, and not help the car to rotate.

Sorry, I should have been more clear; Max camber for the front

So 0 toe in front and rear will provide better turn in / mid-corner?

[jcrane82]

Originally Posted by sprp85

So 0 toe in front and rear will provide better turn in / mid-corner?

Yes, better turn in and more neutral than stock alignment. It is all relative though. Can't say for certain what your perfect alignment setting is since everyone's opinion on perfect is different. When speaking of alignments and handling balance, it is best to speak in terms of relativity. Toe in at the rear adds tendency to understeer. Toe out in the front adds tendency for oversteer. The tires sizes you are running also have a huge impact on handling balance. A staggered setup with have more understeer than a square setup.

I also believe the Dinan camber plates are non adjustable, so there isn't camber adjustment in the front. The only thing you can do is pull the alignment pin at the top of the strut mount and slide the mounts inboard as far as possible.

[joe86]

Camber: F 2-2.5 for street. R 1.6
Toe F 0.1 total toe in. R 0.2 total toe in.

[Suhb]

I've been through a number of alignment specs. My biggest recommendation is DO NOT RUN 0 TOE. You will get better turn in yes, and I saw the benefits in autocross but it comes with the trade off of instability. Especially if you street drive the car and have to do hard braking or an emergency stop, the car gains toe out as it dives and causes instability.

[The Wind Breezes]

My recommendation is step back and think about this for a sec. What is your goal here? You're already driving the car so hard on the street that you need more camber to corner slightly harder? That's really silly. Run stock camber to preserve your braking, tire wear, and the car's stock balance which is more than fine for the street. It's easy to rotate the car under power, so slow down focus on your line and put the power down at the right point!

For driving events sure add front camber but keep in mind those are won based on driving skill (and things like tires for auto-x) so unless you're already very competitive forget about the alignment and focus on the driving.

[Olgeezer1]

Well I settled on the 0 toe up front, slight toe-in at the rear scenario, with -1.5 camber front and rear for a 99% street driven car on a square tire setup. This after talking to several BMW alignment guys about how I planned to drive the car. Works great for my purposes, great handling, even tire wear.