GC8 STi with Group4 and XRD bars

[hamish_richmond]

Alignment query.

I have a Ver6 Sti (MY00) with a swag of Whiteline bits including Circuit Spec Group 4's, alloy links, HD mounts, XRD front and rear bars and loads of bushes.

I also have some custom strut tops deisgned for max castor on the front and camber adjustment on the rear. On the track I use a Bridgestone semi slick tyre.

I have recently complete some diff upgrades and I'm restarting the alignment from scratch, since the car now handles much better with just a baseline configuration. My only criticism is that there is a hint of understeer and turn-in could be slightly better. How can I best acheive this from my baseline settings?

FRONT
Height 345mm
Camber -2.6 degrees
Castor +7 degrees
Toe 0mm
B/R 7 clicks (half firm)

REAR
Height 345mm
Camber -2.2 degrees
Toe 0mm
B/R 14 clicks (full firm)

I would guess that lowering the rear 8mm would help and possibly 1mm REAR toe-out. I don't want to disrupt the rear too much, so if lowering the rear will improve turn in by itself then that's all I'll change.

Also, should I avoid running any rear toe with a plated rear diff?

Thanks,
Hamish.

[Whiteline]

Hamish,

I would start off with either lowering the rear by 5-10mm to provide a slight rake difference. This will provide a slight increase in steering turn-in.
I would also recommend backing the rear shock adjustment off, you should not need to have the rear shocks adjusted any more then 3/4 of the maximum setting otherwise the shock will be over powering the spring and effecting the vehicles handling. I find that the front shocks generally need to be approx. 2 clicks firmer then the rear.
Keep in mind that the shock absorber only needs to control the springs oscillations.

As for wheel alignment settings, you may find that with a plated rear diff you will need to run either 0 toe or slight toe in on the rear, as over-steer on exit is a common complaint of people with plated diffs.
Keep the alignment as is to start with and make changes as required. Try and limit making any changes to one thing at a time to limit any confusion, it also makes it easier to back track and identify what is causing any problems.

I hope this helps you.

Cheers
Wayne C

[black03sti]

G'day Hamish, what are your bars set to?

Cheers,
Shane T