signes

This is correct. Most recent alignment specs from Porsche for front and rear posted earlier are 1.5 +/- 0.05. My late April built car came in right on this.

Was out this weekend i don't see the need to go over 2.0. Outside edge wear is reasonable, although have a lot of room to push more. I am still in the stock middle front and rear bars and I will try going full stuff for the rear bar.

Macca

I run -2.2F/-2.2R currently and find it the perfect balance. Car has done its fastest every lap times with these setting and its also feels very good on the street. Under brakes works well and turn in is sharp. Tyre wear is good enough for the heat cycles I tend to replace the rubber at. All good....

Macca

Pete. You will find -2.0/-2.0 works just fine. Start at 25 and bleed down to 28 immediately you come in. If you can keep the tire between 28-30 hot front and 30-32 rear on the TPMS out there then I think you will get everything you can from those MPSC2 with these settings, likely less rub and more grip too.

For the MPSC2/Dunlop stock tyres I dont think its worth going crazy with geometry. Once we get some alternative options (RE71 etc) then I think it would be worth playing more...

Macca

I should be clear as I see Ive confused a few people.

I day -1.5 degrees for camber is factory. That is -1'30 seconds as per the book (30 seconds is hlaf a degree).

Its always important we speak in the same measurement language. Pete you are right -1'30 (i.e. -1.5 degrees).

If you say -2.0 then it is same degrees and minutes.

Here is the table I take this from (published by Porsche).

MileHigh911

I agree with Macca on SC2 tires and geo. Of course driver style matters too. I find my car best when front are 28-30, and rears are 30-32. Anything higher than 32/34 and the times go off, and the neutrality of the car begins to change. This is with my set up and my driving style. I think most here run a square camber set up, which is traditional for the 911, but I find the rear tires do not need the same amount of camber for even tire wear (rear steering). With the SC2, I want to use the outer tire, but not excessively. With too much rear camber, When the tire wear doesn't ask for it, I think you are using the wrong rubber of the tire (for SC2). For my 15 GT3, I have settled on running -2.5/-1.85 on SC2, with middle/middle bars, 1 mm front toe out per side, and 2 mm toe in rear per side. Even wear on all tires. I also happen to have an aftermarket wing and front dive planes, but I don't believe they come into play when corner speeds are below 90 mph. My car is very neutral. If I need more rotation, I'll trail brake to apex, and the cars post apex power down behavior displays neutral feel to track out. I can create oversteer when desired by varying inputs, but on its own, this chassis set up is very neutral for the 911GT3. One desires even tire wear to get the most from their rubber, and with the SC2, IMO, one doesn't want to over camber them, or they loose straight line braking and consistency of the grip for putting power down. I suspect Other tires would not be like that (as they would have the same compound across). I believe we all fight the balance of sway bar setting and camber settings for tire wear and handling characteristics because Porsche is using "soft" springs to make the PASM work. I think guys are going to full stiff bar to counter rubbing issues and outer tire wear, due to the front springs being too soft. Changing to a firmer spring rate would allow one to play with the bars for the desired handling changes, rather than as a band aid to cover tire wear issues and rubbing issues. I really just need to change to 19 inch wheels so I have access to the 265/325 set I want, with more choices of rubber besides SC2.

usctrojanGT3

What toe are you guys running on the front and back? A little toe out in the front and a little toe in for the rear? Car is going in to BBI in a few weeks before hitting the track in early Nov.

TRAKCAR

You are correct, I just read 1.3 somewhere but as you Point out minutes and its -1.5 degrees.

Seems like the issue is that the tires are only fast when not over heated and they like 30-34PSI.

On cold tracks in Europe they were so much better. There for example after ORouge I watched PSI drop on the long straight. Sebring has a long straight but PSI never goes down.

So even if i start at 23 and end up at 30-32 by the time they get to 30 they are cooked.

My next Sebring event: same tires (10 track sessions and daily driving) so they will go off, but I will set camber to -2 pressures at 28-30 cold and go 10/10 on lap 2 like I dis yesterday with cooled down tires at 25PSI.

I only have no rub, so maybe 1mm lower all around.
Just to see if any rub at all.

See what that does first, next step would be to mess with toe;
A little toe out front might not be felt much in the car with this litttle camber. The rear is very solid.

But a thought on that as well; Some testers have said the car is too loose in short tight corners, I think it could be due to no down force but also the RWS going straight whenthe driver rotates the car as you normally would and stand on throttle with the wheel straight or a little opposite lock. Look at my T7 the more I drive the car through the hairpin the earlier I could go for throttle while not straightening the wheel all the way. I was playing with it so almost drove over the dirt at the exit but another thought.

If all this works in the 90F heat running 2:16/2:17's then I should have a solid setup at Sebring this coming Winterfest / 48 hours..

TRAKCAR

Agreed. Porsche is smart and I first want to feel it out on my own before I start all over with springs. Plus these are great tires for driving home

Now more oem changes and a VBOX.
One day; Springs, Li battery and Dundon headers...

Zero toe front and -1.5 each rear.
I see what BBI does and it looks awesome, locals here have done all that as well but I have no track feed back ...

Plus; Cups are too fast to play with and you pass everything else as it is, except maybe a Viper so why not for now stay oem and fully warranties?

TRAKCAR

PS I'm sitting at a red light on my way to work.
This car is awesome. The only rattle is the tic tacs in the door.
Even the brake pads are quiet and clean

Started it inside the garage door closed.

Not a puff of smoke. Didn't use any oil yesterday

Joe731

Just confirming, with 2,000 gentle (under 4k rpms miles) I took my car in for a track alignment. The pre-alignment measurements were -1.7 front and I think -1.4 rear. I will check next weekend on rears.

I am running -2.5 all around, 9 degrees of Castor and Toe-out of 0.5MM each on front and 2.0mm in on the rears.

Seems to work pretty well. I have tried different tire pressures at different times and cannot say that I have it all figured out yet.

To me, it seems like they like 29-30 hot when newer, but as they age, I have found that a little more pressure 32-33 gives me more grip. I suspect is has something to do with the rubber hardening over heat cycles, but I would have thought it would go the other way. Nonetheless, the data does suggest more pressure as they age. Thoughts on this?

usctrojanGT3

I'll just have them give me a touch of toe out in the front and some in the rear with about -2.5 camber. I'm going to put Brembo slotted rotors, RE10 pads, and Endless fluid and see how things go.

Are you running middle/middle on your sways or middle (front) and stiff (rear)? I definitely don't want a tail happy RS.

What sway bar settings are you running?

Joe731

Medium in front, Full stiff in rear

TRAKCAR

I would love to hear what you think of full stiff front as well.
Dropped off my car yesterday to get setup changes made, will go back late this month to try it out.

Joe731

I have not tried front full stiff, but will play more with it at WGI next season or perhaps VIR and Sebring this winter.

I wish I could remember where I found this, so I could give credit where it is due, but I like this POV on Sway bar settings.

SWAY BAR SETTNGS: START WITH THE END WITH THE PROBLEM FIRST

Soft Front Bar
• Increases front traction of the car while decreasing the rear traction.
• Increases the roll of the car.
• Over steers the vehicle.
Stiff Front Bar
• Decreases front traction of the car while increasing the rear traction.
• Decreases the roll of the car.
• Under steers the vehicle.
Soft Rear Bar
• Increases car roll.
• Decreases front traction while increasing rear traction.
Stiff Rear Bar
• Decreases car roll.
• Increases front traction while decreasing rear traction.
• Increases Steering sensitivity during high speed cornering.
As even minor changes can have sizable impacts, it is suggested that any adjustments to sway bar suspension are done with great care and if possible, using professional tools.

Mika911

^^

Are you mixing up under and oversteer regarding the front bar?