For street setup no need for camber plates.
With just 4mm shims i could go well over 2 degr.
Main issue is rear camber can't be increased to match the front dues to rear toe limitation.
So we had to dial down front camber to 2'10".
If you want to go for more camber - rear toe links are a must.
An then a bit more shims front and rear - i think you can get close to 3 degr.
More than that is required only you're a true track rat.

 

Correct, you can dial a lot of camber with just shims as long as you don't run out of thread on the inner LCAs....the issue with shims is that you are moving the wheels off center, the more shims you add you are also adding caster, and after 2.7-2.8 negative it can become a problem.
If you add a 265 tire you are also adding a whole 1" on section width.....you can say you are extending 0.5" the outer edge of the tire and getting very close to the edge of the fender....you will need to push that top of the tire back into the fender.
If you stay stock wheels-tires I did -2.5 /-2.0 with 7 mm front spacers and only shims....worked pretty good as a dual street/track setup.

 

Rear toe links are a given. I’ve battled the rear toe issue since the 986 so this retrofit was already in the mix. No warranty issues here in the US with that swap, not like what you have in Israel.

My target setup will probably be in the -2.0 front + 7mm spacers, -1.5 rear range for aggressive street use, depending on what John and team come up with at BGB. My main reason for considering the Motorsport camber plates is to optimize castor. If I can get -1.5 out of the plate and the rest from a small shim I’m thinking I’m in the sweet spot for overall geometry.

Maybe I’m over thinking it wouldn’t be the first time.

 

This is what i had with just 4mm additional front shims.
I didn't feel caster issues.
And i usually like reduced caster with lighter steering feel.

 

Note the highlight above. I asked earlier how much shim people were seeing from the factory but didn't get an answer. Of course I'll know when I get mine but that's a few weeks away. In all likelihood I won't need the camber plates but I've budgeted for them regardless.

 

here they said 7mm shim from the factory.
IIRC i had the same.

 

The front wheels are noticeably further inside the fender wells than in the rear. Just awaiting the addition of 5-10 mm of shim to make it look right and help balance out some the the car's OEM understeer. As you add more shim, you can balance the caster with the camber plates or use solid adjustable thrust arm bushings. The later are cheaper to purchase, much less expensive to install, and give you precise adjustment for the caster. They will also tighten up your steering since you are replacing rubber with steel....like on an RS car.

 

this is similar to my current set up WITHOUT any mods the factory set up I'm running now is 1.65 fronts and 1.85 rears you can get to 2's limit using the standard factory parts btw.

 

Question for people with about -2° front and -1.5° rear camber.
Did somebody play with front/rear bar setup? I am middle/middle but there is still a bit of understeer on corner entry. Corner exit instead is from neutral to mild oversteer with enough throttle. I think I might go soft front sway bar because I have a lot of caster and camber and tires might work very well. Does sway bars affect more corner entry or corner exit? I am worried that with softer front bar I might have the same understeer on entry and more oversteer on exit. Opinions?

 

I'm no expert, but I don't think you are going to get much more. If you go softer in the front or stiffer in the rear, you will induce more oversteer on exit. You will also lose some initial turn-in bite by softening the front sway bar. To me, it sounds just about where this mid-engine's car natural balance is at.

Any changes going forward will have a positive effect in one direction, but maybe not so positive in the other direction. There is a balancing act and anything you do will affect both the front end and rear end.

Sounds like you have a pretty good balance now, slight understeer on initial turn-in is a very momentary phase and maybe just adjust your driving style to it. I don't think you want to induce more oversteer into the rear on corner exit.

 

i went with both sways on full stiff.
but i had damping fine tuned using TPC's DSC.
no understeer for me.
actually quite oversteary - but manageble.

 

When I set the 981 GT4 track record at Watkins Glen in 2017 I ran full stiff rear, full soft front bars. TPC suggests the same settings when using their rear toe link or DSC. When first tracking the car I ran full stiff Front and Rear and didn't like it.

 

I just ordered adjustable Tarett endlinks so I can experiment w/ bar settings in smaller increments by having un-matched settings on either side of the bar. Next time I'm at a track I know really well I'm gonna try it out. My car as-is (with TPC offset toe links, and DSC Sport) is pretty close to neutral, but does experience some mid-corner understeer. However, the car is also nicely adjustable w/ throttle and subtle steering inputs. Maybe I'll end up where I started w/ the bars!

 

Don't know your driving style, but trail braking into the corner will pin the nose down with a little extra weight on the front wheels. This will give the car more front end bite as you enter the corner.

 

I actually think the GT4 could use a little extra caster. I drove one at a good pace this last weekend and felt the front-end and steering get a little too light for my liking after about 90 MPH. I think going to -2.3 ish negative camber with shims and allowing the caster to go a little more positive will be a great thing for high speed stability.