ja78911sc

I have two sets of D90's 7's & 8's and run 225/245 16's on my 964. We all know 16's in a R compound are becoming more difficult to find--limited selection.

The pricing is better on the 16's when compared to 17's.

I follow almost every tire thread and I have come to the conclusion that I am the only guy running 16's on a 964

This leads up to my question. Will I benefit now changing to 17's--better handling, grip, etc. on the track?

The 17" wheels I have will accomidate 225/255 tires (i am a wheel hoarder--avatar pic ). Based on this, I feel like a change will only effect my wallet. Doesn't seem like much of a upgrade.

Thanks for any input.

J richard

I ran/run up to 245F/295R 17s on my 964s I think the sweet spot is 235F/275R in 17. I like the 18s better but the wheels get heavier and the cost goes up. I think you're on borrowed time on 16s. If you had some really nice lightweight 16s I would hesitate but hell, D90s? The 964 is about the most flexible platform in terms of wheels I'd start looking for some 17s and move on...

Ps: I run 8"F 10"R wheels...

ja78911sc

J Richard, I agree on the borrowed time when it comes to 16's. The 17's I have collected are 993 cup II's and the width will not allow for the larger sizes you listed.

I have a friend running 18" 245/295 on CCW's. I can't justify 3K for a set of wheels. The D90 is a good budget wheel and at this point don't see much gain changing to the 17" cup II's--until I have no other options.

Greg Phillips

There are lots of 17" options.
You can get 275/40/17 on the 9" Cup 2's
You can also look for the 7.5" Cup 2's (or aftermarket) and get 235 or 245 on them.
Some people also use the 8 inch cup 1's on the front rather than the rears they were designed for.
Greg

J richard

^^^this

If this is for DE then by all means run your D90's and save the money, but if you are time trialing or racing you are leaving time on the table with the 16s. The 17s are cheap! If you want 18s the turbo twists, sport classics, or narrow spokes are all available to fit, and they are all OEM quality, and can be found around a grand.

ja78911sc

Thanks for the input guys!

Greg, with the 9" cup 2's (55ET) and a 255 on the rear the tire is dam near rubbing the oil line with around -2.0 camber. Did you have more neg camber or maybe you are actually referring to cup 1's (aftermarket) with 47 ET and a 275?
Thanks, Jim

Greg Phillips

Actually my experience with the Cup 2's are on a 928

But I do run 275 rear and 255 front on my 911SC (with rolled fenders)

You may need spacers to get the clearance needed on the inside or use some of the other Porsche (or aftermarket) wheels with less offset.
I was commenting on what tires fit on the 9" rim and I have seen RSA drivers using that size.

Greg

KaiB

Either you're rubbing the oil line, or you're not.

If not, why worry.

ja78911sc

Agree, but my concern was that a 255 on a 9" (ET55) is almost rubbing so a 275 on the same wheel will most likely rub?

ja78911sc

Greg, thanks for the info. I do have a aftermarket 17" 9 (47 ET).

Is there anyone running a 275 on a 17" 9 (ET47) wheel on the rear of a 964 that can give me some feedback on clearance? Thanks!

race911

I forget what offset I actually ran on the two RSAs, but they were the old Cup 1 replicas everyone had back in the Olden Days. 275-17, with a 1/4" spacer. Yes, longer studs too.

As far as the 225/245-16 thing, yeah we ran those in the before-the-Olden Days when the 964s came out, with the '90s BFG R compound (the Groove Of Doom tire that we ran at ~20psi). You could never keep the rear tires on the car at even a little more than pony trot pace. So I'm not sure what point there is with running those 245s at a ~3200 lb. on-track weight.

ja78911sc

Ken,

Thanks for the input. I did a little more research, prior to your post, and this backed up the spacer and longer studs with a 275 you mentioned--replica 17" 9's (47ET).

245 in the "Olden days"

I just converted to a smart phone six months ago. I am usually the last to update.
When I purchased the D90's, they included a brick phone with the purchase

Jim