Originally Posted by Protocav

63 offset is perfect, just remove the 5mm spacer from the hub. -3.4 sounds like way too much camber in the rear, and I don't think there's much benefit, unless you are running slicks. I'd put 1 full degree of positive camber back in. My tires wear perfectly even at -2.5.

Sounds like the front is ready for a big tire, but if you put a 275 on a 8.5" wheel, it will fit really bulgy and fit improperly. I'd put a 9 or 9.5 up there for the appropriate tire. That being said, I've been very happy with a 9" front, and I even run a huge front sway bar, softest rear bar setting and a squatted rear. Essentially, I'm searching for rear grip because I trail the car a lot, and on paper the car should push, but it doesn't.

Caster should be 7.5-8 regardless of ride height because it centers the wheel nicely, but over 8 almost guarantees that it's going to rub in the front.

I don't know what my official frame-measured ride heights are, but the ground to fender arch center measurements are 25.5" in the front and 25.75" in the rear. This equates to very little rake (probably 10-15mm), as I felt rake only contributed to the rear end coming around.

Originally Posted by CosmosMpower

I'm running Pirelli DH but I can back off rear camber, I just did it to not have too big of a split between F and R. I need to find some front 9 or 9.5" wheels, when I ditched my CCW's and got the OZ's I didn't realize the fronts were only 8.5 and I was running 235 or 245 so I didn't really care. I just checked and it seems all the OZ porsche wheels are only 8.5 not available in 9"

I'll back my caster down to 8 as well, remind me when reducing caster how does that change the other alignment settings like toe or camber (if any)?

Originally Posted by CosmosMpower

Holy crap 1.5 seconds faster? I think I'm going to have to do some experimenting soon. Problem is not sure if there's a common Pirelli DH in 275/335

Originally Posted by powdrhound

In as Pirelli DH, I run a 275/645-18 and 315/680-18, standard 7.2Cup tires. In the NT01, I have switched to a 275/35/18 and 325/30/19. This gives me almost the same diameters as the DH.

Originally Posted by CosmosMpower

I run the 315/680/18 paired with a 235/245 and it's not bad, with the 305 the rear is a little looser than I like. How is the balance with the 275/645 and 315/680 DH? Does it have too much oversteer? I already have my front bar at full stiff and my rear bar 2nd hole from full soft. I'd be worried that adding that much more front grip without a 325 or wider would upset the balance.

Originally Posted by powdrhound

Since those are 7.2 spec tires, it's set up per the 7.2Cup manual but with a bit more camber both front and rear, -4.1/-3.5. Car is a 996 but suspension is essentially 997Cup but with lower roll centers. Suspension set up naturally depends on many variables to get you to your end goals. I'm on 1700/1800 lb springs but will be stiffening the front another 100lbs and rear another 200 lbs. Front bar is middle on a 5-way and rear is one from full soft on a 4-way. Balance is neutral with a touch of understeer on entry. The extra 100lbs of front/rear spring split should dial that out. Here is a video to give you an idea of the balance. Car is very easy to drive..

https://www.youtube.com/watch?v=Gx2xbkR7VLQ

Originally Posted by CosmosMpower

Thanks for sharing, our setups are apples and oranges. I'm on a completely stock 997.1 GT3 suspension. I'll report back once I find some 9" front wheels and try the 275/315 setup or maybe 325 if it fits.

Originally Posted by powdrhound

275 on a 9" wheel will not work, The tire will be way pinched and roll over. It will perform far worse than a 235 or 245 on a 9. In order to get the benefit of the wider set up, you have to do it right. For a 275, 10" wheel is key, a 9.5 at a very minimum.

Originally Posted by CosmosMpower

I can't even find a 9.5" front GT3 wheel, which wheel do you use?

Originally Posted by powdrhound

BBS E88 18x10 fronts. You can build the E88 as a 9.5 but if you're gonna do that you might as well do the 10.

Originally Posted by CosmosMpower

Big $ any other alternatives? I'm accustomed to 2k a set OZ's lol

Originally Posted by powdrhound

Unfortunately not that I'm aware of..

Originally Posted by CosmosMpower

Looks like Apex has a SM10 that's pretty cheap in 18x9 and 18x12.

The 18x12 rear is 65 offset which with the factory 5mm spacer is 60 which is perfect. The front is 46 offset, is that too low?

Originally Posted by powdrhound

18x9x12. What size and brand tires are you looking to run?