I know the R brakes (even the steel) are larger. Does anyone know if you can fit 19" wheels to an R coupe?

 

yes

 

Thanks for the reply, but can you please specify which question you were answering? In the title, I asked if 20" were required. In the body, I asked if 19" will work...

 

The superperformance brakes that are "optional" on the V6S are standard on the R. The V6S can be fitted with 19" wheels in that configuration, therefore 19" wheels should also fit the R when those brakes are fitted.

 

The next question is surely why?

 

Less rotational mass, less weight, more sidewall space for track tires, and less expensive track tires.

 

I have often wondered if the V6 would work better with the standard 18" Velas, all other things being equal.

Effects of Upsized Wheels and Tires Tested - Tech Dept. - Car and Driver

 

Do you know if the 18" Vela would fit over the superformance brakes? I'd love to shave another inch if possible.

 

I don't know the answer to your last question as my base V6 came equipped with the std. brake package w/ the Velas. I stumbled across an opportunity to acquire a slightly-used set of silver 20" Gyrodynes on P-Zeros, which were sold by the owner of a black R-Coupe, who had to have the carbon fiber wheel option.

My perception is that my car handles better with the extra rubber, and ride quality is about the same, but that is, of course, very subjective not having done any comparison testing of any kind. I certainly like the look much better.

Nonetheless, after giving you a data point against going smaller, I would perhaps part with my perfect condition set Vela wheels and tires at a good price should you decide to go that route. On the other hand, I'm also inclined to keep them and possibly mount all-season tires at some point.

 

Sorry for my incorrect answer earlier. My dealer told me the large brakes were the reason 20" wheels are standard. One thing to check out is the actual wheel weight. They vary based on design, metal composition and method of creation. On my BMW M5 I know the 20" wheel is actually lighter than the 19" wheel for example. The best answer in your case is probably to get a lightweight wheel. A 19" BBS FI would dramatically reduce rotational weight.

 

Sorry, I don't know. The combo is not offered as a factory option, so the only way to find out would be measure or try them.

 

Although I currently have a F type R, I used to have a XKR and if I recall correctly the brake sizes are the same.
On the XKR I had 20" wheels, yet in the winter I put 19" wheels and taller tires (snows) on, so yes the 19" should fit.
You may wish to try the fitment on a front wheel with a 19" to double check.
Lawrence.

 

I just measured the clearance on my R. In the front, there is approx 0.6" clearance between the caliper and the 20" wheel. A 19" will *just* clear, but it would be pretty close - enough that I wouldn't do it. No way an 18" will fit though...

 

Less rotational mass? LOL. Come on. These rims weigh what, 30-35lbs? The car has 550hp? Have you actually done calculations to determine that yes, you need a smaller rim? Did you compare the weight from a 20" to a 19"? I mean, are you that sure that you need to take an already almost perfect automobile and downgrade it to gain time...

...what are you trying to do? Make the Kessel Run in 12 Parsecs?

 

Respect!
I think another user, MarcusXFR has previously pointed out the superior utility of smaller rims.
Personally I like the look of 20's, but you are right about the utility.
Props for bucking the trend.... It's good to be bad

 

Yes, respect--well said! And Scott is right. Sticky tires with a little more sidewall definitely work better on the track than the 20" "rubber bands," and 18" track tires are much more readily available. Rotational mass, which is unsprung weight, would definitely be less as well. Unsprung weight vs. that associated with the rest of the car is multiplied several times (I think at about 4x) in terms of a performance penalty

I've been in touch with him tonight because he has a track day coming up soon, and I offered my Velas here earlier. However, after looking at my car tonight, and as others said earlier, I don't think they are likely to fit. The clearance between the std. calipers and the 20" Gyrodynes is considerably greater than what I recall it being on the Velas.

Scott is doing the research.

 

Thanks, everyone! It seems that the 19" option is the way to go to gain a little more sidewall and save a few bucks on track tires.

As for the look of smaller wheels...who cares when you're on the track? I won't get into the logic of going to smaller than 20" wheels on the track, as Foosh just laid it out eloquently.

And thanks, Foosh, for all your help and even offering to sell me your 18s -- very kind. Does anyone on here ever refer to you as Chip Foosh?

If anyone has a set of 19s that they'd like to offload, shoot me a PM asap.

 

Good luck, Scott.