2 or 4 wheel alignment on M Coupe?

Ok, I know this is another stupid question...

I know the rear has no adjustment that I can think of...

Do I need a 4 wheel alignment? Or can they just do a 2 wheel alignment?

I finally got the four fenders at the same height. That was a bit of work for sure. Adjust, put wheel on, wait, measure, pull wheel, adjust, replace wheel, drop car, wait measure...

I am measuring from the center of the wheel hub to the bottom of the fender.

Whats the benefit of adjusting caster? I have adjustment with the camber plates, but I dont know if I need to do anythign other than leave it all the way back.

I think the car off almost 3/8ths of an inch from right to left. Should I be concerned about this? I have the coil set at a different height on one side vs the other to compensate.

Anyways, thanks in advance for the help.

Reply » 2 or 4 wheel alignment on M Coupe?

Be careful of relying on fender heights to get the car's balance right. It is a real posibility that the frame, body and spring perches are off slightly. Even a 1/4 inche hear and there will change the corner balance of the car. You should really have the car corner weighted to make sure that the weight distribution at all 4 corners is within a 100 lbs or so - regardless of the axle to fender gap. Just about any race prep shop should be able to do that.

If you have an improperly cornerweighted car, your car will turn differently to the left and right. Typically more understeery one way and oversteery the other way.

Besides, it's pretty hard to look at both the right side and the left side at the same time.

That out of the way, the only factory adjustment is the front toe. Unless you add camber/caster plates up front and IE toe, camber adjustments to the rear....

You can probably get some movement out of the top hats and subframes, but not much.

Caster changes camber gain (or loss) as the front wheels are turned. More caster results in more gain/loss and will give a higher steering effort. It will change how the weight distributes to the corners during a turn as well as the bump steer effect. Longacre has some good tech articles on this topic. Targeted at oval racing, but the principles are the same. More caster is not necissarily a good thing.

http://www.longacreracing.com/articl...at.asp?CATID=2

My 2 cents.

Reply » 2 or 4 wheel alignment on M Coupe?

Ok, so I should just set all the coilovers to be the same? Even if they are off 3/8ths from one side to another?

Reply » 2 or 4 wheel alignment on M Coupe?

from speaking with a alignment guru in LA, you should check the rear alignment anyways b/c you want to know whats going with your car. What I also found out is the car sits naturally higher on the driverside by a tad. Once I got in the car, he said the alignment just lined up perfectly. Ingenious desgin? who knows

Reply » 2 or 4 wheel alignment on M Coupe?

Ummm, well.... it really depends on a lot of other factors. The shock towers could be off, the springs could settle differently, the springs could have slightly different rates.....

Only real way to set adjustable coilovers is to have the car corner weighted (or scaled).

Baring that, I'd set the coil overs the same for each side and at least you will be no worse then then you had stock springs and perches.

It only really matters if you drive north of 7-8/10ths at the limits of tire adhesion.....

Reply » 2 or 4 wheel alignment on M Coupe?

BTW did you:

a) Check with a person weighing about as much as you do in teh driver's seat? If not, the heights will be off when you are driving it.

b) Move the car back adn forth and bounce it front and rear before measuring? If not, the suspension wasn't truely settled.

Lastly - get it corner weighted, with you in it, that is the only proper way to set the spring perches. And the starting point for corner weighting is setting the ride height, so what you have done isn't totally wasted.

Page 1 of 2