NJ-GT

On the 997.1 GT3 and 997.1 GT3 RS, for track/street use on DOT-R tires:

Front: 100mm, -3.0 camber, 0.05 toe-out per corner, sway bar in the middle.
Rear: 120mm, -2.5 camber, 0.25 degrees toe-in per corner, sway bar at full stiff (if using 1st generation bar) or middle (if using 997 GT2 bar that supersedes the 1st generation bar).

This is a baseline, then start fine tuning from here, each car is different.

speedyralph

I would love to be able to start at that baseline, but I don't have suspension components to get those camber numbers..

I guess I could max both cambers then reduce the rear by .5?

NJ-GT

Yes, you do. The rear axle gets to -2.5 on the 997.1 GT3 at that ride height. At the front axle, just rotate the strut tops, and add 4mm of camber shims. You could also save on rotating the strut tops, and add 8mm of camber shims.

speedyralph

Perfect.

I could use the shims off these control arms from my other build and add them onto this car.

Would you know how many mm's are these shims?

NJ-GT

Those seem to be the Porsche OEM 7mm shims.

My RSS control arms (installed in the Cayman) came with a bag of shims, 8mm, 3mm, 2mm and 1mm per Lower Control Arm, a nice gesture from RSS.

Tarett engineering in San Diego sells shims for a good price.

With 7mm of shims as you have in those control arms, you still need to rotate the strut tops, or you would get to -2.8.

Rotating the strut tops is very easy:

1.- Disconnect the front sway bar
2.- Loose the nut connecting the front Lower Control Arm to the subframe
3.- Loosen up the three nuts on the front camber plates, but don't remove the camber plates. Use an air tool (I use an cordless impact drill) to remove the shock shaft from the camber plate.
4.- Now remove the camber plate
5.- Press out the studs from the camber plate and press them in using the unused 3 holes on the camber plate. You will notice with the camber plate on hand, that using the other 3 holes, moves the center bearing (shock shaft hole) closer to the car (towards the inside) increasing camber. There is an added benefit, you get to run wider tires without rubbing on the front fenders.
6.- Reinstall camber plate
7.- Attach shock to camber plate, use a floor jack under the front wheel carriers to help you move up the shaft through the camber plate bearing.
8.- Power tool to tighten the nut that holds the shock to the camber plate.
9.- Torque the LCA nut
10.- Reconnect sway bar

Now to the alignment rack.

speedyralph

Thank you very much for this info!!

Ok, so add these shims and rotate the tops. That way the alignment guy has enough to play with.

On my green car I bought the RSS control arms and yes, they are nice. Rodger at Orbit didn't like them though...

speedyralph

I forgot to mention that the knuckles rest on the point nearest to the bolt. Should it be there?

Mvez

I'm currently close to this setup, but am going to try the 100mm/120-122mm height. With more front spring, I need a bit more rake.

Front: -3.1 camber, Zero toe per corner, GMG sway in middle
Rear: -2.45 camber, 0.19 toe-in per corner, GMG sway in middle

NJ-GT

Yes, that's the right one, use the center hole, no need to use the eccentric hole.

utkinpol

You want car to as low as geometry of front arms allows you to go without having to utilize bump steer arms. It mostly depends of what uprights you have and some other factors. It is too much to type - search it or ask any mechanic who setups cup cars. Rear end is usually ends up set somewhat close to half inch higher than front depending of how corner balance was done and what aero setup is used on a car.

utkinpol

It depends of how his frame was welded - those are for basic caster correction. Best way is to ditch those pucks and put on solid steel together with adjustable fork arms

AGO

If you're not running toe in of about .20 to .25 on the rears maybe is something to check before changing the rake (it worked on my .2 GT3)... anyway you have quite a bit of expert setup options above to play with. Let us know which route you took...

997gt3north

I have had many alignments since I started in 2007 - I use the car to drive to the track, DE the car, drive home, occasionally take it for a spin. The alignments I've had:
- factory spec - car pushes - didn't feel good on the street
- factory circuit spec - car pushes, felt better on the street, eats rear tires inner edge
- (-2.7, -2.4, slight front toe-out) with GT2 bar middle, car very neutral with the slightest, slightest of rotation on exit - push totally gone, front tires not using outside edge, still slightly too much rear tire inner edge wear, car feels like a dream - absolutely like a race car
- (-2.5, -2.3, slight front toe out) with GT2 bar on soft, softening the bar from middle to soft takes away the slightest of rotation - either setting works, it is a feel thing, tires better, but still room for improvement
- (-2.3, -1.8, zero front toe) with GT2 bar on soft, better tire wear, car basically neutral - it is not an all out race spec setup, but it 100% works on big fast tracks like Mosport, works with various types of tires, combined with all the RSS rear suspension hardware and the re-valved suspension, the car is a delight to drive - extremely predictable

If I drove shorter twisty tracks, I would probably go back to GT2 bar in middle or maybe even hard - but I wouldn't recommend that to those starting out - if you are perfectly connected with your car and getting a lot of seat time, then there is something almost magical about the tiniest bit of oversteer at every track out point that allows the rear of the car to use every last mm of track surface - but for most people GT2 bar soft maybe middle is a better setup.

Nizer

+1

speedyralph

Whats up members!

Im doing the ride height thing now. Should I have a full tank or half tank of gas??

I know the manual says "full tank", but I've read that some people have done it with half a tank..

Thanks!!!!!!!
RAlph