ace37

Trying to see what wider tires people are using on the TT/TTS and how it's working out.

Questions:
For those using 12" wide rear rims, what tire type and sizes are you running?

For those running factory sizes on 12" rims, any issues?

Background:
I was looking at getting a set of rims for my incoming TT so I can have a snow tire and wheel set and a summer tire and wheel set. I'm not sure which set the OEM wheels would be used for, and at this point I'm going to just wait until the spring.

It looks like there are three main tiers for 911 TT/TTS wheels:
1. ~$10k premier forged coated/painted pocketed wheels with certifications. Lots of great wheels and the very lightest weight options seem to be in this range.
2. ~$6-8k forged wheels that may or may not include coating and certs. Lots of great wheels and very lightweight.
3. Cast $2-3k "flow forged" wheels that occasionally have certs and a coating. Not super light but not super heavy either. Reasonable way to mount winter tires.

The thing that surprised me was a lot of options, even at the top price point, are sold in 20x12" rear sizes rather than the OEM 11.5" rim width. The reason that surprised me is because the 305s are at the wider end of the rim recommendation on the factory 11.5" wide rims, so they're getting a bit stretched on a 12" rim. (Tire rack and my dealer advised against it; perhaps they're just being cautious.) It would make a lot of sense to go to 12" widths if there were good tire set options in 315/30R20 or 325/30R20 sizes, but a bit of searching left me scratching my head as there really aren't a lot of tires out there in those sizes... not everyone is running trofeos.

SilveRT8

X2 for that question !

tommyboy214

I ran into the same question when looking into a new set of rims. In the end I just pulled the trigger on a set of BBS FIR 9x20 and 11.5x20 and will use the stock set up for tires.


I am cross posting http://www.6speedonline.com/forums/9...-rear-rim.html

on the 6speed I asked LunarX, who is knowledgeable on wheels and tires.


Hope he doesn't mind me sharing the information
------------
Originally Posted by lunarx
Hi,

For the fronts, its a no-brainer to go w/ the 9".
I always pitch the 255-35-20 tire, for a 9" wheel.
A 245-35-20 is silly small for a 9" wheel.
You did not ask about offsets, but I feel a 46-48 is about where you want to be (for front 9").

For the rear, I was also contemplating 12"+.
Unfortunately for an AWD Car the 315-35-20 is too much of a diameter difference, to subject the center differential to.

305-30-20 would be crazy stretched on a 12".
With AWD you don't need a wider tire, so the prudent thing to do is keep the 305-30-20 on an 11" or 11.5" wheel.

If you had RWD (no center differential concerns) you might be able to entertain going 335-30-20, which is what I was considering.
I believe it would fit with a 12" & 80mm offset.
Not sure if anyone has done it though.
In the end, I think it adds a-lot of weight, so its too much for my weak NA S to spin.

Although a Turbo could handle it, the extra traction of AWD makes such a big rear tire unnecessary.

Ideal is 315-30-20 on a 12".
However, I only know of Track Tires being available in those sizes.

With RWD I would do 315-35-20 on a 12" but also bump the fronts to 265-35-20 on a 9.5"
That's the setup that I am considering (for down the road).
I just cant advise that for an AWD car, since you need to keep F/R rotation ratios, within an acceptable range.

Another thing to keep in mind is that the P-Zero Tires don't look as stretched as the PSS, if that means anything to you.

Hothonda

Tom...Not understanding the 65-67 rear offset quoted....

OEM is 56. Those ↑↑ numbers tuck the wheel in lots...I would be going the other way.

OEM w/56 with a 15MM spacer = 41 which seems more logical.

Mistake?

What are the BBS front & rear offsets?

tommyboy214

Honda was a mistake and I pulled that section. The BBS wheels i went with have a ET48 for the front and ET46 for rears.

On another note alot of folks go with the 325 rear as well with the 12 inch set up.

Hothonda

↑↑↑ Sounds perfect Tom.

I'm close to doing a similar set up.

THX

tommyboy214

Honda almost pulled the rigger on these but in the end wanted the BBS.

https://rennlist.com/forums/parts-ma...s-sensors.html

ace37

What tires are being used in the 325 size? Trofeo Rs?

tommyboy214

I believe folks run the P Zeros too in the 325

Karl911

I have been running 265/35/20 325/30/20 MSC2 on stock rims for about 1 1/2 yrs on and off the track, absolutely no issues,well a little inner liner rubbing on lock to lock turn, and I am lowered too.

PTGFAR

GT3 comes with 305/30/20 on 12" wheels.

ace37

Thanks, glad to hear a good experience.

Interesting - did not know that. It sounds like in part my dealer was being conservative then!


I was thinking 265/325 MSC2s might be nice but if a 12" rear rim width will support either those or the stock sizes it's a pretty easy decision to go with the 12" rear rim widths.

Thanks all for the contributions and information!

Randyc151

Karl, have you found those tires to be scarce? Seems like TireRack is always out of stock.

PTGFAR

I checked with Michelin on the recommended wheel size for the MPSC2 in 305/30/20 and they said 10.5" to 11.5" width. It's interesting that Porsche chose to use a 12" wheel.

abiazis

My 2017 Turbo S has 11.5 inch rims in the rear? Were 12" optional?