In preparation for the coming track season I had my dealer increase the negative camber as I had a lot of tire chunking last year.
How much camber are other people getting out of a stock 981? I presume I'm reading the paperwork correctly, and that they were only able to add in another -.5 degrees in the front. I was thinking I saw others getting closer to -1.7 in the front.
I got -1.75 camber in front with the X73 suspension. I've heard PASM will get to -1.50 in front. I'm a bit surprised you can't get at least -1.0 in front with the stock setup.
My Porsche dealer could only get -1.4 front out of my X73. I then took the car to a race prep shop (going down the slippery slope) and he was able to get -1.7 by "trying harder". Apparently there are a few additional adjustments that can be done to get the max camber available and the dealer just didn't want to go through the effort.
I started off with the race prep shop. People I'd been going to for a while. They managed -1.5 front (X73) without problem. I meant to ask what the max they could have managed was, but didn't.
Negative 1.5 degrees on Front with PASM... tech said "there was a little more, but not much left"... so perhaps it might have gone to -1.7. Beyond that, would need camber plates.
Going by tire temperatures alone, the -1.5/-1.8 camber we've got is a bit much for the track, though not excessively so. The camber is about right for autocross.
Just like dynos my experience shows that various shops give you various Neg Camber results, you cant quite compare directly.
A race Porsche shop here in Sydney (many Carrera Cup cars go there) use a Flat patch concrete base on their wheel alignment equipment. Then use lasers and fishing wire to ensure car is perfectly flat and stable prior to alignment. As they are on the other side of Sydney I sometimes use a Race Suspension shop around the corner.
Their readings differ quite a bit from the first in regards to the readings they provide - They use a traditional light style alignment equipment in this shop. Like you see in a lot of shops.
How much? Depends on the tires you choose, your suspension setup and ride height, your driving environment (street/track) and your driving experience. Camber and toe are also inter-related so if you can manage a little toe-out in front, you can find a bit more negative camber. It's complicated.
My car is currently running about -2.5 in front, and -2 in the rear. Stock shocks and springs, GT3 LCAs, dual purpose running RE-11s and NT-01s.
My shop got -2.0 in the front and -2.4 degrees in the rear with a stock X73 suspension. On 235/275 (F/R) Nitto NT01s the fronts are getting pounded and I'm getting clear understeer at the limit. I'm hoping the move to 245 width front tires next time I buy tires will help mitigate this some. The shoulders of the front tires look like the tire could use a bit more camber, alas its not going to happen without suspension hardware changes.
I know that X73 alignment specs specify more negative camber than the other suspension systems, but I am wondering if X73 is capable of more camber than the other suspension systems.
And if so, is it a function of different alignment-specific components, or is it just because X73 rides lower and therefore flattens out the lower control arms more, bringing them more parallel to the ground and thus moving the lower pivot further outboard.
Just lower. The lower you go, the more negative camber is available. Go too low and you run out of toe adjustment and generate bump steer. I personally think the X73/Cay R ride height is close to optimum for Cayman suspension geometry.