Alignment looks good Fadi except your rear toe which shows +12' left and +17' right. You want +17' both sides. Also check your monoballs for any play. Always align the car with 4 new tires. I would install new fronts as old tires can cause weird stuff.

As far as the vacuum pump goes, you want the 7GT2 pump, NOT the 7GT3 pump. They look the same but must be slightly different internally since they carry different part numbers.

 

Yes, good idea but already verified caliper and not stuck, we did brakes test too. Having IR meter so will try the test you indicated. thx !


That toe is one of the last 30 geometry setup we did ))) Yes not 100% the best way , but even when it was equal the behaviuor was the same. Also we tried some narrower Cup2 at some time and quite the same result.




BUT... HAVING NEW INFO

I managed to get in contact with my old mechanic, and seems the car had the same problem even before, more than than with the car suspended on the lift and front tires in the air if we were turning the wheels to the right, they were returning to the left, even on the street I remember that was a slightly turn to the left, but I thought was due to the sway bar or something else.

Seems the only thing that made the car go almost straight (very very low turn to the left) was to install the swaybar into different location/points left vs right

This was last year setup with H&R front sway, not installed GT3 oem sway and with the sway equally installed left&right the car on the elevator dont return wheels when turning right, they stay there not coming back to the left.

My next move will be to do the trick we used into our last setup, to use different install points left vs right and see from there. Surely this is not the cause, but a good workaround, will report back if not going crazy with this :P



For the pump, thanks for the tip, I think have copied/paste your setup )) some might have the 997 gt2 pump, have to verify

 

Hi Fadi,

I would check the front shock mounts. If these are still OEM, chances are that the rubber is broken and that the upper reference point is kinda moving.

Regarding your sway bar: you shouldn't have any binding in them with wheels pointing straight. Mount them with the car not on the lift or only on a suspension setup lift. There shall be no force necessary to mount the links. You can drive without sway bar and see if it contributes to the problem at all.

Your rear toe values are asymmetrical. This car really depends on a symmetrical toe setup, especially on the rear. In the front an asymmetrical setup will most likely result in a misaligned steering wheel and tire wear, but not like you describe.

Check the thrust line of your alignment (axle misalignment). Although your wheel base is close to OEM, left and right could be asymmetrical (left front tire a bit behind for example).


Andreas

 

Dear Andreas, good hints all of them, but the worst part is we have already passed/played wih all those tests/setups and no progress

We put the sway at the 3rd whole and respectively on at the second whole the other part, and the guys from the shop telling me the car isnt turning left anymore, that is weird as I dont know where this is coming from, and for sure we solved the effect and not the cause, but still the result isnt that bad.

Still having to sort out the 4460 - Pressure sensor and guess good to go out and play

My braking system has for now only Master Cylinder pump 997 and 997gt3 calipers running 380/350mm setup.

 

The aggressive left turn issue seems strange. Most of the common things that could cause this would happen in left and right turns. If a sway is binding disconnecting the front bar would fix the issue. Possible sway mount moving around?

 

Thinking about this issue a little more from an alignment perspective I have a couple of thoughts that may or may not be relevant.

If it is only in left turns then we can be reasonably sure that and toe or camber shifting that may happen would likely show odd characteristics in right turns also. Possibly what is happening is either your toe in the front or back is moving around causing oversteer in left turns and understeer in right turns. So that the issue is more evident in left turns even though both directions are affected. The same could be happening in camber I suppose. But given the history of our cars having shifting toe more often I would suspect that.

Also, even if you align the car that does not necessarily rule out a worn part that is loose and moving around in corners. And keep in mind that a camber shift usually effects toe too.

 

This is the final product, car is more stable and quicker almost everywhere now and more predictive after finishing suspension fine tuning, having a fresh set of slicks and going to smash my track record next year, all these if not going to change it for 991.2TTS as to be honest I find it very tempting with all new gadgets and having 2 kids now and might get back to a 4 seater

Weight is 3240lbs with 10/13 inch rims and tires (275/335), 380/350 brakes, including 100% full tank of gas and full tank of water/meth, full interior, 2 x FIA racing seats, full OEM carpet front and back and some add-ons like cup style floor boards, racing display etc, FIA certified fire suppression system, half roll cage, OEM battery, only missing - Bose and A/C. Can go maybe 200lbs less if giving up some gas, light battery, 1 seat and perhaps some of the interior or at least lighter carpet. Can still do carbon roof and rear gt3rs or cup windows to shred like 30lbs more on top, but car is really able to be street driven now as decided to keep for now the 996tt brake pumps to have psm on/psm off and psm fully off from in cabin switches

The video bellow shows the street trim of the car, for the track car has
- lowered setup
- modified joe tooth front lip to fit wide body kit
- 18" rims with wider tires (in the vid 245/305 R19 MPSC2 with huge spacers)


Hope you like it and open for any suggestion

 

Looks sick man. Love how it turned out

 

I don't see a video

 

Very nice Fadi!!!!

 

Hi guys,
i can get a set of rear brake calipers. They are red and seem to be for 997 TT/Gt3
I still use the stock 996 TT ones with 350mm rotors both 4 pistons.

99735242611 and 99735242511

these should be the ones with 34/34 piston area right?
thx

 

Looks perfect, use it in good health!

 

AFAIK all 997 rear calipers have 34/34 mm pistons. I have a set of those for sale. As well as some other brake stuff....and GT3 front uprights.

 

Can anyone confirm this?
Its a set of rear calipers from a 997 GT3 MK2. They are red colored, so not the PCCB ones.
If found these numbers for the 997 Turbo too.
97.352.425.99 & 997.352.426.99
They seem to fit.

Thx in advance!

 

Just found the info on page 8 in the thread.
So i bought the right stuff with ceramic inlays.

@ John: what about the use of different brake pads front and rear? You said with stock abs the use of pfc 08 in front and 11 in rear would good.
So the less agressiv pad is in the rear right?