2016 981 GT4. Stock suspension except DSC controller, with max camber (-1.7 ish/-1.5). I use Sport Cup 2s and experience what most others do...the outside edges wear. Whenever I measure temperatures across the tires they do not seem to be overly out of whack. If I go to something like -3 front and -2.5 rear, will that provide more grip in turns? I'm not concerned so much about tire wear as Cup 2s do last quite a while for me. I'm interested in more camber if it gives me more grip and enables me to carry more speed.

I've read the track wiki over and over. Lots of different opinions and a couple posts suggesting camber will not fix Cup 2 edge wear. I usually do my own work, but am thinking to get someone to do this suspension work and it ain't cheap!

 

Depends how fast you are currently, but certainly more camber will make the car capable of lapping faster, yes. What're you running the sway bars set to? With your alignment on stock suspension, I think full stiff on the rear, and between medium and soft (ie. medium one side, soft the other) on the front is likely best. Plus or minus half a position depending on preference. The stock medium/medium is way too understeer biased. Try that first if you're not there.

But yeah, more camber is helpful. I went from about where you're at to -3.9° front, -2.5° rear (9.5° caster, -0.1° total front toe, 0.3° total rear toe), along with slightly stiffer springs, and 19" wheels (9" fronts). Altogether was good for a little more than a second around my local ~1:20 track. Car feels much a lot better too; much less scrubbing of the front tires. (Even after balancing with the sway bars as mentioned above, which helped a lot, I still felt like it was scrubbing a lot on the stock setup, hence outside edge wear.)

 

Thanks for the reply! I'm med-med on sway bars and will move rear to hard. It seems in my recent reading of threads on this topic having the rear on hard is the way to go. Should have done it before now.

I reached out to GMP (in Charlotte) about more camber and their solution was Tarett LCAs front and rear and they recommended adjustable rear toe links as well. I did not specifically ask them about caster, but it seems a lot of people add camber plates as well with some people mentioning better caster control with those.

 

Why tarrett arms, doesn't the gt4 already have adjustable control arms? Should be able to add at least a degree all around for basically free. With how the front swaybar works with the super stiff mount bushings, I don't think the "half step" settings are a good idea. Either leave it middle and stiffen the rear or put the front full soft.

 

Why tarrett arms, doesn't the gt4 already have adjustable control arms? Should be able to add at least a degree all around for basically free. With how the front swaybar works with the super stiff mount bushings, I don't think the "half step" settings are a good idea. Either leave it middle and stiffen the rear or put the front full soft.

All in all it might not result in a noteworthy time improvement but it should make the car feel a bit better and be at least a little easier on tires.

 

The GT4 has split lower control arms so you can add motorsports spacers to add camber, this will push the track width out for each mm of shim you add and once you go beyond 2ish deg camber you'll lose ability to keep caster in check in the front and very quickly will lose adjustment to keep rear toe in check. you need rear toe arms, front thrust bushings (additional caster adjustment) and then you can get -2.5 front and rear, beyond this you'll want upper strut mounts which will gain you 1deg of additional camber and more clearance. win win using the strut mounts from dundon, tarret...

 

I would reach out to Brad at Digital Chassis in Durham. He certainly is the Porsche alignment expert in the triangle. There is definitely more time to be had from an aggressive alignment. Going to monoballs can help too. Walking a fine line between street comfort and track performance if you push too far.

 

Thanks for the recommendation James! I definitely would prefer local and Durham is perfect. I will call Brad!

 

Yeah, the alignment I mentioned above was done with front camber plates, thrust arm "pucks" (caster adjusters), adjustable rear toe links (I went with the TPC offset ones), and a shim kit. I also got adjustable tie rod ends, but I'm not certain whether they were necessary given I got most of the camber with the plates. I don't think aftermarket control arms are necessary if you're getting camber plates. (As mentioned, I got to -4° in the front, and I don't think you'd want more than that.)

 

Looks like you’ve gotten the camber question answered buuuuut my $0.02 is not to chase tire temps or use them as the primary indicator to change setup. For sedan based cars (meaning not a race specific “formula” style chassis), you’re never going to get even temps across the tire face. Watching wear patterns is a better idea and something you’re already taking note of.

Side note: adding camber at the front should add more front grip an hep turn in a little… you might want to hold off on going stiffer on the rear bar at the same time you bump up front camber. If you decide to do them both at the same time, just be aware the car may feel a little more pointy.