Cory M

Any issues with running Yoko 280/680 slicks on a 12" wide wheel. The recommended rim width is 11". Most manufacturers typically allow +/- 1" from the recommended size but I haven't seen anything official from Yokohama stating that. I'm racing on a tight budget and am looking at running used Cup tires on my older 911 GT car. I don't want to have to rebuild the rear wheels if I can avoid it.

jakermc

If you find the answer, I have a set of lightly used Yokos in that size available for sale. Might even have two sets, need to check.

jrgordonsenior

The 2010/2011 GT3 Cups have been running them on 12" rims for the past 2 years....

Cory M

Perfect, thanks.

mobonic

I have run them on 11" and 12", they seem to like 11" rears better but its a small difference imo

James-GMG

Cory,

We have run the IMSA spec Yoko on both an 11.5" and 12.0" rear and didn't see much of a difference in performance.

I don't see a need to rebuild your wheels at this time.

And keep in mind, we will have a lot of left-over 2012 spec Yokos from this year as we will run close to 70 sets of the season so we will have some nice used ones to consider.

Cory M

Thanks for all the info. My rears are 12" but fronts are 10.5-11" depending on the set. I put a 230 slick on one of the fronts and the wheel looked way too wide, I couldn't even fill it up with air. I am planning on converting one of my sets of front wheels to fit the slicks. I was going to reduce it to 9" but it looks like the new cups are running 9.5". Which size front do you think would give me the best compatibility with used slicks?

My main motivation is simply reducing tire costs by running used cup slicks when I can. I'm not sure if I'll be racing on slicks or DOT's this season. I'll have to compare the tire life, and performance change from the slicks versus the additional weight I'll have to carry. So far I've planned on sticking with DOTs because they last longer and I don't have to carry so much ballast. Yokohama has a nice POC contingency program but I'm not running a full season so I don't know how competitive I'll be anyway. I have bought my share of used tires in the past and it has been a mixed bag, some were great and others were junk...

James, I'll definitely keep you in mind for the tires. Good luck at Daytona.

jrgordonsenior

Cory if you're sold on running Yoko cup series tires then you're using 240 fronts so 9.5 should be the max width for that tire. If you're running Hoosiers I'd just use you wide fronts with the 12" rears and run their 255 fronts (which are really 275's) with their 305 or 315 rears. It really comes down to tire choice first andwhether you have the power to push the really wide tires. There's a point of diminishing returns with wide tires. JP ended up sticking with cup sizes on the Yellow Bee after trying both and he's got 400 to the wheels....

PS: Are you coming to WSIR with POC in Feb. If so and you're running a GT class PM me and I'll walk you through the paperwork. We're having our dyno out that Saturday....

Cory M

Right now I've got Hoosiers, Kumhos, and Nittos all mounted up in 275/285 F and 315 R. I don't make anywhere near the power of the Killerbee so I might actually benefit from the smaller tires. I think I'll pick up a pair of inner rim halves from Jongbloed and try it out.

Sent you a PM about WSIR.

James-GMG

Cory,

With the wheels sizes you currently run, I would seriously consider the World Challenge Spec Pirelli.
We run 18x10.25 fronts and 18x12 rears with their 275/645/18 fronts and 315/675/18 and they are awesome!

In fact, we set our own personal best lap time at Willow last December testing at the big track with a 1:19.1 which was .3 seconds faster than the bigger Michelin blue N1 slick they just came out with in the larger size for the 2010+ cups.

The Pirelli tire can take a beating and will last longer than the smaller Yoko. Trust me on this, I have race both and Pirelli's latest slick is very impressive.

I will have a ton of them as well as take offs from this season and they are cheaper than the Yokos!

I will be up at Willow on Feb 9th for our GMG Track Day (Open to all Porsches!) and then there for the POC weekend so let me know if you are interested.


Thanks,


James