alexb76

Not sure, will measure and let you know. But if you have Sport PASM, you're probably already lower 10mm vs. mine (997.1 PASM). I know that at my height installing the aerokit or GT3 bumper scrapes all over the place and that's about 0.5" lower.

EDIT: Sorry, thought you got 997.2 Sport PASM, but it sounds like we're both 997.1, will let you know how my ride height is.

RonCT

Ken, when I tried Damptronics, we went down about 3/4", which would be about the same as -10mm from 997.2 Sport PASM height.

KeninBlaine

Right on. My installer and I agreed this morning that we'd try 3/4" and see how it looks. Will see tomorrow.

johnwb

I see a lot of references to what the front camber setting should be, but not much on the rear.
I have a stock 997S that will see about 6 DE days this season. I'm going to have an alignment done next week and will ask the tech to give me as much negative camber in the front as he can. I understand from these posts that it won't be any more than -1. What is the best bet for the rear wheels? Thanks.

alexb76

Take a look at post#23, that's Porsche recommendation. I'd go with the Performance settng.

johnwb

thank you

mdrums

Keep the front to rear camber with in .5 degrees of each other. With stock suspension on a stock PASM car around -1 is all you can get. This will help you a lot at a DE though....so if you get -1 up front stay at -1.5 for the rear.

once you get more experianced with your car you can add GT3 lower control arms up front and these will aloow up to have much more camber up front. Then you can dial in more front camber than the rear. This will free up the feeling of the car even more added much more grip to the front end.

KeninBlaine

I had Damptronics installed on my car this week, and had the alignment set to ROW Performance. I had the car lowered about 5/8", so the top of the front fender wells are now about 25 3/4" and the rear wells are about 26 3/4". While a little lower would look more aggressive, this height seems good for a DD. Plus, there is a chance the car may settle a little over time.

The alignment is now as follows:
Front toe: +5'
Front Camber: -3/4 degree
Rear toe: +20'
Rear Camber: - 1.5 degrees
Corner balance: 49.8%

My installer said that with the lowering of the car, the -3/4 degree front camber was the minimum achievable (he would have preferred -1/2 degree). I can't believe how much better the car feels and handles now. The steering is much more responsive. The suspension is slightly firmer, yet still compliant and comfortable. In sport mode, it doesn't feel as "jiggly" as the old sport mode felt, so I find it better.

acadian_dad

Sorry to resurrect an old thread - but curious about your comment of keeping the rear numbers within 0.5 deg of the fronts ? Presumably this is a balance thing ...

I recently had my '05 997-S Cab in for an alignment - I found I corded my rear Mich Sport Cups at the outer shoulders long before the rest of the tread was getting used up ... I mean right at the shoulder - the zig-zag pattern on the outer tread block was still intact.

This was after two long days of open lapping at Calabogie (newish track with fairly abrasive pavement and tends to be rough on tires) as well as a PCA DE at Mosport and another one at Watkins Glen (neither of which added any significant wear to the tires). I run the tire pressures at 34-35 hot ... which seems pretty typical for MPCSs so I don't think it was due to under inflation.

The front camber was -1.2 and the rear was -1.7 ... couldn't add any more front camber (am looking into the GT3 control arms but haven't done that yet) but in the rears they upped the camber to -2.3 to improve the wear ... but this means I now have a pretty serious offset between front and rear camber unless I put in the GT3 control arms. Am I going to be looking at some serious under or oversteer with this setup ?

In terms of putting in GT3 control arms - is there anything else required or recommended other than the two control arms per side ? New ball joints or tie rod ends or anything ?

Mike in CA

FWIW, Michelin recommends 32F-36R hot for the MPCS. You might find this info from Michelin interesting.

http://www.tirerack.com/tires/tirete...nd_Feeding.pdf

acadian_dad

Yes - that's a handy resource. I guess I should have reworded my statement to be that I know a bunch of guys running about 34-35 hot without seeing the kind of wear I was getting.

atr911

Understeer. With the added neg in the rear you're going to hook up like nobody's business back there and it will actually INCREASE your front tire wear in the front by ploughing you through corners. The problem with running R compound tires without LCAs or Camber plates is that the outer shoulder of an R comp is designed to be very grippy/soft and most R comp manufacturers recommend fairly drastic negative camber numbers (slicks are even worse).

Adding neg in the front isn't usually to bad for tire wear as the weight up front is much less than the rear. Negative camber in the rear is going to increase wear exponentially. The GT3 track cars that are driven aggressively found that even on 100% track use, at -2.4 degrees in the rear, they wore rear tires too quickly on the inside. For a street car I can only imagine that you're going to slaughter your rears with all that negative out back.

I have two tires on my counter at the shop that I used for less than 5000 km on the street (90%) and track (10%) with -2.3 in the rear and. You should stop by and take a look. Might even get a chance to see my new state of the art, flush mount alignment rack being installed.

ADias

Is this tire pressure recommendation independent of vehicle type ?!?

utkinpol

i have ruined set of hoosiers in same exact way having -2.3 front -1.9 rear camber with gt3 lcas.
problem is not with camber alone but with amount of sway and very soft springs PLUS soft sidewalls on those tires. bumping pressure up helps a little bit but you loose optimal sweet spot for traction.
now i run on kumho v700 which have square very stiff sidewalls and there is no damage to edges at all. it works properly with stock springs.

ultimate fix is what i get right now (car in the shop) - 600/700lbs springs and JRZ RS shocks. sliks in general require non-stock stiff suspension when car is pushed a lot in the corners.

complete suspension rebuild is about of $10K job, 996 gt3 LCAs are $600 for pair - that gives appx idea of a range here. If you are serious about going away from stock suspension - consult with a good builder in your area. I would simply try better tires first, like toyo RA1.

atr911

For my Hoosiers they do have a recommended pressure but if you call them they'll tell you to run a little more in the rear (36-38 rear and 34-36 front).

It is true that with the rear weight bias the tire pressures should be a little different than the 'assumed' front engine.