Javelin
Javelin SuperDork
4/10/11 10:46 a.m.

The 225/45/15 RS3's came in (and the new ball joints) so it's going to the shop next week. What is a good alignment spec for a 944? Autocrossed once a month, street driven 500 miles a month (3-seasons only), run on RS3's all the time, so I can rotate the the tires and will already be on a short replacement cycle so let's err on the side of fastness.

Oh yeah, rear LSD and sport suspension (non-adjustable) if that makes a difference. It understeers bad now.

docwyte
docwyte Reader
4/10/11 11:00 a.m.

You need camber plates...

Javelin
Javelin SuperDork
4/10/11 11:46 a.m.

I don't have those yet. Does that mean I can just tell the shop "maximum camber"?

docwyte
docwyte Reader
4/10/11 8:47 p.m.

Try to get as much negative camber as possible in the front.

With camber plates I run -3.2 in the front and have my rear adjusted to get -2.x

I do run race tires though, that much camber would be excessive for street tires...

motomoron
motomoron HalfDork
4/10/11 8:56 p.m.

The best alignment is the one that results in nice looking wear and as uniform a temperature across the tire as possible. Pretty much any RWD car w/ IRS wants as much F-camber as you can wrangle w/ about a degree less R-. Zero front toe or a little toe out if it doesn't like to turn. No rear toe in or just a hair if you're having trouble getting power down on corner exit.

Then take temps and adjust the camber 'til you're as close as you can get across the tread.

On my M3 (e36) I run -3.2F -2.1R camber, no front toe, 1/16" side rear toe in. It works great everywhere.

Javelin
Javelin SuperDork
4/11/11 8:30 a.m.

Thanks fellas!

njansenv
njansenv HalfDork
4/11/11 12:57 p.m.
motomoron wrote: . Pretty much any RWD car w/ IRS wants as much F-camber as you can wrangle w/ about a degree less R-. Zero front toe or a little toe out if it doesn't like to turn. No rear toe in or just a hair if you're having trouble getting power down on corner exit.

Without wanting to go on too much of a tangent... Doesn't that vary significantly from design to design because of the the dynamic camber curves of the car in question? I'd be more inclined to agree if you said "Mac strut RWD cars"... but even there it's hard to have a hard and fast rule due to different suspension kinematics.

joepaluch
joepaluch Reader
4/12/11 8:35 a.m.

For autocross you might try some front toe out to help with turn in. I run zero toe on my 944 race car, but that is a different enviroment.

However max out the camber on the front to -2.0 or -2.5. The key is past -2 you may not get the same maximum as it depens on the tolerances in struts and so you will be limited by the smaller size.

In the rear rake makes difference. You can adjust rear the ride height by using the two bolts on the spring plate. These are large nuts. One is normal and the other is eccentric. The eccentric can raise or lower rear by 1/2". This will produce a noticeable diff in balance, but it also impacts camber so set the ride height and then do camber after. For my race car I run level front to rear, but I can also play around with spring rate and adjustble sway bars to achieve balance.

Our Preferred Partners
JEQzpV8ttkFpeSn16Ffu11Ty3Y7InyPL