hmhaga

I've just finished installing AST Sportline Is, AST top mounts front and rear, R180 diff and powerflex bushings (all rubber bushings gone). Now for the fun part - setup! Some question my decision to build a "track day weapon" of a wagon, but why not?

Rather than reinventing the wheel, I've decided to use some of 911's settings from the "perfect chassis" thread as a baseline. 335 mm ride height front and rear, 7 clicks front, 6 clicks rear?
As for alignment, I've installed the top mounts so that they increase both camber and castor at the front. Anyone who knows approximately the resulting max camber and castor angles when doing this? -It "looks" pretty nice... The plan was to run -2.5 degrees front and -2.0 degrees rear.

As for toe angles, what do you recommend? I've decided to try zero toe both front and rear. I see some recommending 1-2 mm total toe out at the rear, but I have a bad habit of being "overtaken" by the rear end (probably an even more likely outcome now with the R180).

If you have any track days aligment settings to share, please do so!

911

Remember i had 50/40 springs with those damping settings.
If you have 60/50 then go for 10/8 clicks from fully soft.

I have zero toe front and 20 mins in the rear toe in (iirc).
Caster is about 4 or 5 deg posative.

On radial tyres almost 3 degs neg camber all round.
I do not like the sound of toe out on the rear imho.

Remember the roll bar size/setting will have a big influence as well as pressures.(and change in pressures over track time)

You have come to the tricky part now!

harvey

iTrader: (48)

Is this purely a track car or a track and road car?
If the latter then as perhaps 98% of the time is road then extreme road settings would be best.
Here is what I suggest which will also result in better tyre wear.

IF THE REAR HAS TOE OUT IT CAN ONLY MAKE THE CAR UNSTABLE?NERVOUS. If it is a rally car you might consider this setting for flicking the car side ways before a corner by steering in the oposite direction to the corner and then turning into the corner with the rear coming our and the car rotating on its centre in the direction of the corner.
This style has no place in normal circuit or road driving where smoothness is the order of the day and while rock apes may look spectacular with the tail sliding about they are rarely faster.

Front Camber -1.75-2.0 deg.
Rear Camber -1.25-1.5 deg.
Give consideration to how stiff or flexible the sidewalls might be.

Toe : Always more on the front than the rear.
Front : 15'-20' toe in.
Rear : more than 5'-10'

Do you have facility to measure and adjust castor???

hmhaga

Thanks for your input! Think I'll settle for zero toe both front and rear then (except that I do ice racing in winter, where I do flick the car as Harvey describes to get the car sideways). My springs are 50/40 btw, and the tires are Proxes R888.

If it wasn't for the track days, my car would still be in stock condition. I've come to the stage where I've bought a Citroën Saxo VTS as a daily driver and a Porsche Boxster for the summer. So now my Impreza is finally free to become a dedicated track day car -with matching setup In short, "extreme settings"

To have some additional fun, I've decided to do all the setup and alignment myself. Nasioc 4 wheel alignment guide

I only have basic tools, but have sourced an angle meter from my father working with aircrafts. I spent half a day to get the front ride height and camber angles right, now at -2.6 deg (I gave up struggling with the last 1/10 to land at -2.5 deg). I tried plexiglass plates with lubrication in between to allow the wheels to move freely, this worked surprisingly well. I guess the worst part is to get the rear toe angles right...

hmhaga

I've finally finished setting up the suspension, at least version 1.0 beta
Doing this at home in the garage really was a tedious task, but it was fun and very educational. One funny thing was that I could push the car in all directions by hand power, so the plexi glass skid plates really worked.

-2,0 degrees rear camber didn't look right at all, so I set it at -1.5 degrees. During the test drive afterwards, the car felt nice and I was happy to see that the car drove in a straight line with the steering wheel centered. Now, time for a track day

911

Excellent. The 'string' method is actually used by Prodrive on Event too!
Saw the set-up last week.
Here is my car with 2.5 deg camber all round:
https://www.scoobynet.com/scooby.php...to&photoid=606