So, im rubbing in the rears w/ 17x9 +40, 255/40/17. Im rolled on all 4 corners, and i rub when i hit dips, fronts are ok tho. Should i mess with the stock adjusters to get more camber? Any specific alignment specs would help any would greatly be appreciated.
Thanks

 

As much camber in back so you will not rub.
or
More rolling and pulling.
or
overfenders.
or
park it at car shows

 

what are you currently at for camber? that would help determine where you should go. if you are only at -2 out back you culd probably add in just a bit more and be fine. If you are already at -3 or more. I would look to roll and flare a bit more. Or go to a 245 tire.

 

17x9 +35 with Michelin 245 PSS tires at 1 finger gap and -2.7 camber and some toe dialed in. I don't rub and might go with 255 tires next.

Edit: Rolled and Tab relocated in the rear btw. Just rolled didn't work for me, I had to relocate the tab, that did the trick.

 

Do not go to wider tires just because you can. Tires need to match your rim width. A fatter will bulge instead of the slight stretch you want. Bulge will kill your handling, riding on donuts.

From Urge Designs:

Match your tires with a slight stretch

Another thing to consider is tire width. Many people believe that wider tires improve grip. However, this is not true. You need to fit your tires to your wheels so they have a slight stretch. Fitting the widest tires possible on specific wheel sizes will deaden response and cause the car to roll due to unsupported sidewalls. Additionally this will decrease the performance and function of your dampers as you introduce a major damping mechanism into your system. Extra tire width is not used as the tire is pinched; creating a muffin top close to the wheel lip that is not in consistent contact with the ground. It’s important to note that none of the racing series above use tires that are wider than the wheels. Every team has their tire widths matched to the wheel width. On TV you will noticed a slight stretch of the tire as the wheel is slightly wider than the tire.
URGE designs has experimented with multiple sets of 10.5” and 11” CCW’s to get the offsets and backspacing perfect for the S2000. With little to no front fender modification you can run 9.5” front wheels with 245mm tires. For S2000s that visit the track more often we recommend 10.5” wide front wheels mounted with 265mm tires. You’ll need to modify the front fenders with a big flare or replace them with at least 25mm+ over fenders. If you’re willing to go all in with 11” wheels, we recommend that you have at least +50mm front fenders and +25mm rear fenders and suggest running 295/30 tires

 

Yep, generally speaking you want to match to the nearest mm without going over, the rim width to the corresponding tire width to maximize the performance handing and grip of that specific tire choice. For example. 225/9" 245/9.5" 255/10" 295/11.5". This is especially important on a 17" package where there is more sidewall and therefore more inherent sidewall deflection. On an 18" you can generally drop the rim width .5" with the same corresponding tire width outlined for a 17" ( assuming your dropping the tire series as well for shorter sidewall and same overall diameter)without compromising the max performance.

 

So sticking with my current setup is best?

F17x8 with 215
R17x9 with 245

 

That would be the ideal mates yes. You can up size to a 225/255 stagger for some marginal grip increase, but at some sacrifice of handling precision, if that’s a worthy trade off (which usually it is for track) After that, any further up sizing on these rim widths for the sake of grip would be diminishing returns, the deminished handling aspect goes without saying.

 

OP, are your rears rolled and tabs relocated/trimmed?

 

Yes, screw moved out to 1/2 to 1" out i believe. I found out my rear bumper fender (trim after bumper tab/screw) is what was making me rub badly. So I trimmed off alot of the rear bumper, to where there is almost no rear fender bumper left. Im not rubbing as bad, with getting aligned to -3.5 for the rears and raising the car to about 1 finger gap.