LeVeeNRRR

Hi guys,

Just joined the forum and only had my 996tt for about 3 years. So recently been running into some tire/wheel fitment issues. I'm just trying to find a clear way out before the season starts and hoping if anyone had the exprience can give me a little insight on their thoughts. If you see I make any mistake or misspoken anything, please kindly points out, i am still relatively new to the track community. Thanks in advance!

I am going to list out the issues I am running into and the tought process along with my questions so for future reference, people won't be in my shoes hahah.

So I got Apex's SM-10 (18 x 9" et46 front, 18 x 11" et36 rear) freeflow wheel for my 996tt by going with Apex wheel's official fitment guide. I fitted a falken 615k 235/40/18 in the front and 315/30/18 rear (GT-2 fatorty size) with -1.5 degree camber in the front (no camber plate). I also have a KW V3 installed as well. The rear is perfect, never runs into any issue.

With this set up i have encoutered these 2 major problems:
1. 235 looks a bit stretched on the wheel. So when tire is cold (30-32psi) on the track, it will leak air under load (always the left front tire), and it is very dangerous because it will just all of sudden let go, tire pressure drops to 11 psi one time even single digit. The tires were put on by professionals and it happened 3 times already and did ruin 3 sets of my tires.


Just a little bit stretched


2. The wheel is rubbing kw suspension on the little pod that is stick out. This is just something i didn't even think of since that little side pod on KW v3 is tucked away above the breaks, when suspension is decompressed, it hits the wheel at the top.

So my question is, does anyone has even ran into similar questions? I thought about the following but couldn't decide what to do so if anyone has any prior experience, i will be greatly appreciated!!

1. Use 245/40/18 tires.
This should fit better with the 18 x 9 x et46 wheels. but the main problem with this solution is that it will be very tide on the fitment. or I would def need camber plate. But will the camber plate clear out the suspension hitting issue? If i add in only a set of 5mm spacer in the front, will that solve my problem without camber plate? I there anyway i can test it myself without putting significant money into it?

2. swithc to a 18 x 8.5 et45 wheels, this is a narrower wheel from apex on SM-10
This solution should make the 235 tire fits better but how much, will there still be any stretch? Also will this clear out my suspension rubbing? Also if I want to put a 245 tire on this set up, will the fitment work?

On current stage, I am thinking i should try putting in a 5mm spacer and get the 245 tire to see if that will fix the issue. if not, i guess i need more camber.
I also shot an email to Apex wheel to see if they have any recommendations.

But anyway, thank you all for your time!!

and ofcourse, a picture of my car hahhah:

993GT

the wheel is hitting the reservoir under compression???

LeVeeNRRR

when decompressed yes, right at the top of the inner rim, slightly rubbing the reservoir

Rubbing where the black line is

993GT

that distance between the reservoir and wheel should never change...is the damper loose in the upright?

theprf

Or the tire is flexing excessively, or the wheel bearing is shot, or the wheel is flexing.
How much space between the tire and the canister with the car stopped?

docwyte

Sounds like you've got a tire bead that isn't seating. Can you clock that suspension reservoir away from the tire?

s65e90

Something isn't right. The tire should not be losing air like that and the wheel certainly should not be hitting the strut resi. I have similar fronts and same suspension.

powdrhound

The distance between the shock reservoir and the wheel is "fixed" irrespective of shock compression. . The only way it could vary is if you had a grossly worn out wheel bearing or a bent wheel which allowed at the whole wheel to wobble.

Capt. Obvious

That tire is not stretched, it is perfectly within spec. You have another issue.

2fcknfst

1. 235 looks a bit stretched on the wheel. So when tire is cold (30-32psi) on the track, it will leak air under load (always the left front tire), and it is very dangerous because it will just all of sudden let go, tire pressure drops to 11 psi one time even single digit. The tires were put on by professionals and it happened 3 times already and did ruin 3 sets of my tires.

I have run into this exact problem before, either the Schrader valve is leaking/not seated correctly, or, you have a hairline fracture in the wheel - this is what I experienced, it was hard to locate, slow and would only go to 24/25psi and stop.