Dan J.

Hi,

I've searched threads and wanted to see if someone could share their experience on this.

I'm running CCW 10.5" x 17" rear wheels and Hoosier 275/40 tires on the rear of my stock fendered, late offset 944. I need to remove the wheel and check backspacing/offset - not sure what it is.

With my current ride height and alignment (-2.75 deg camber) there is approx 1-1/4" space available to the fender (not yet rolled lip) and less than 1" gap available between the inner tire and control arm.

The specs from Hoosier say the total tire width = 11.25" and the Nitto is listed at 12.48".

Anyone out there running 315 17" Nittos on the rear? If so, what backspacing and width is your wheel?

I want to confirm before ordering tires. I'm not finding 275 17" Nittos available right now and would like to try the 315s if they will fit.

Thank you in advance!
Dan.

odurandina

you're going to be close. i'd go for it. that size tire is ok for your rim. you might end up needing a 7mm spacer. if you run a spacer make sure you run longer studs and have them milled to 7 mm over stock. if you were to buy a typical 315/35/17, it'll get very close to the fender (because it will be about 25.7"), and require rolling the fender... if you get something used, they'll be at least 3/8" of an inch shorter.



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Red1

Not yet. I have the wheels to do it (17x11.5) but couldn't find 315s when I needed tires.

Dan J.

Well, the next time you need tires at America's tire the 275s cost $202/ea and the 315s are $223/ea and both sizes are in-stock.

Dan.

Yarf

Dan

That is a lot of tire, tell us about your car.

Dan J.

Well, after several years of tracking mostly stock 911 variants, I bought a junkyard-bound 944 NA non-sunroof coupe and over the past year have rebuilt it with a turbo tranny, solid bushings, big brakes, cup suspension and an LS1.

The project has been a huge challenge from the start, and I just got it running a few weeks ago after 10 months of working on/off weekends and evenings. Early results are promising though. As others have reported about v8 conversions, this thing really pulls.

For tire/wheel options, I have a set of Cup 1 9 & 7.5 x 17"s that have 225 & 245 Nittos. That combo worked well for my 964, but it's not enough rubber for this car. I'm going to sell those wheels and go with something bigger.

In the short term, I picked up a set of CCWs and am shopping for tires. I heard and have read that 275's all around work well on 944s, but may want to try 315's in the rear.

In talking with the tire shop, they will try 315's for me if I agree to pay a restocking fee if they don't fit.

In eyeballing the way the current Hoosier 275's fit, the extra width of the 315 is going to be really close.

Thanks in advance for all the information - Rennlist has always been a fantastic resource and I have a lot to learn about the 944 world.

Thanks,
Dan.

docwyte

I have a LS1 951. I run Toyo RA1s 275-40-17 on Cup 2 17x9 all the way around. I ran one track day with this motor in the car on them last fall and it did fine. I've since swapped cams and added a bunch more power and am curious to see how the 275's handle it.

TonyG is running 315's on widened Cup 2's, so 17x11. I know he's using the factory 930 spacers in the rear, but I don't know what offset he ends up with...

TonyG

I run 315's on the back. Actually... I run 315's on all 4 corners :-)

The backs are factory Cup 2 wheels, 17x9 55mm offset which were widened on the inside 2", then using a factory 930 1" rear spacer to push the wheels out.

With -2.5 degrees negative camber the fenders had to be rolled and pulled slightly.

275's are for girls. A 315 is a mans tire.

TonyG

docwyte

How are you fitting the 315 up front?

How much pulling on the rear fenders did you have to do? Mine are factory rolled already...

Dan J.

I have a set of 345 Hoosiers on new CCW wheels sitting in my garage right now that are going on a friend's C6 Z-06. Now that's a tire. Looking at those got me thinking about the 315's for the 944.

Just posted my Cup I wheels for sale. It's too bad they never made those in wider sizes than 9.5" because I've had several sets over the years and like that look. Besides they are really easy to clean. I thought about having the Cup wheels widened but I think at this point I'll use the CCW's I have now and I pick up some wider 17"s when the time comes. I'm thinking after-market will be lighter than the Cups anyway.

I ordered both 275s and 315s and will try each next week. The tire shop will charge me a small restocking charge if the 315s don't work out. The 315s should be about 1.25" wider section width than the current Hoosiers on the car. It'll be close but worth trying. I don't mind rolling the fenders because it's a track car - I don't have time to fiddle with different offset/spacer configurations right now.

Headed to T-Hill next weekend and it will be the first outing for this car and my first time at that track - so there are lots of other little details to sort out between now and then. Down the road I may go with wider front fenders and rear flares, but for now I'll be plenty busy learning the car as it's currently set up.

Thanks for the input guys.
Dan.

TonyG

The hot setup is a 315 square. These cars need more tire in the front than they do in the rear. Especially if you run a wing.

And the setup for a 315 square is very different than a 275/315 setup.

TonyG

TonyG

For the front... > 1" wider AIR fenders :-)

The for the rear, just get a heat gun for the paint and a fender roller. Disconnect the sway bar and use a floor jack to push the wheel all the way up to check for rubbing.

You don't need much pulling on the fenders for clearance if you have a neg -2.5--2.75 camber. But the trick is to have a wheel with the correct offset. My setup puts the inner tire within 1/8" of the inner fender. Same deal for the front... I have less than 1/8" between the spring and the rim. But it doesn't rub, and that's what matters.


TonyG

Contadino

What does it take to run 9" Cup 1's in the front? I have a stock '89 turbo.

TonyG

I don't know the offset of a 17x9 Cup 1 wheel. But I suspect it's probably the same as the same sized Cup 2 wheel, which is a 55mm offset.

If that's the case, with a track alignment... meaning -2.5 degrees of camber... , you can run the 17x9 wheel with a 275 tire with no problem on a stock front fender, assuming you are using an aftermarket coil over strut (the small diameter spring is the deal which allows it to fit).

TonyG

docwyte

Just negative camber and 5 lug nuts. I'm running stock '89 front suspension with camber plates and -3.2 camber and the 17x9 ET55 Cup 2's with 275's fit perfectly.