245

For DOT tires
Road Race and Autocross
275/35/15 Hoosier, and rumor has it that Goodyear is going to start making that size in road race and autocross compounds as well.

245/40/15 Avon makes a tire that size for Lotus I believe and it looks like a race tire that could be usable as a street tire similar to a Toyo R888 but difficult to get in the US. Rumor is a couple other tire manufacturers may be tooling that size as well. I think that size would stretch nicely on a 10" wheel.

Non DOT race tires
Hoosier and Goodyear I think both make tires that could work on a 15X10 with workable outside diameter I think.


Overall Diameter is key. Cutting and flaring for width is easy but much bigger overall diameter and your into tubbing the fender wells to retain sufficient suspension travel for a proper handling car. Probably want drop spindles as well.

Bob

I have done fairly extensive clearance and articulation studies on my car which is set up pretty well and determined I need an ET of 20mm for proper clearance on the inside both front and rear. So 5mm spacers for me with the 15X10 6UL’s.

On the front it hits the bump on the inner fender around the shock top. Peeled off significant chunks of the inside corner of the front tire in a high grip sweeper when I tried spacers to an ET26 with the 9” wheels. In the rear actually the sidewall of the tire hits the frame just above the shock top where there are two bolts heads sticking out at full bump with ET26.

Note: Using NB rear knuckles will have an eqivelent effect as adding 5mm spacers for the rear. The geometry of the knuckle pushes the wheels out 5mm more than the NA.

My suspension setup is -2.8 in the front -2.5 in the rear. And I use all the available bump travel the NA chassis has to offer with my currently tuned for maximum bump travel custom DIY shock tops. I also use the 2.25” springs like the XIDA and no problems there.

My Double adjustable XIDA’s show up next week. Happy birthday to me.

Bob

CAD rendering from a few months ago. Color is off a bit but you can see the slightly concave face of the 10.

http://949racing.com/15x10/15X10_6UL_590px.jpg

Wheels still scheduled to arrive in August? If so, any idea on early or late? :bowrofl:

Hoping so. We'll see.

Oh and thanks for quoting the pic. I dig that.

Hmmm....I'm gonna need a sarcasm meter on that one. I hope they come in my car should be finishing up by then. BTW I actually like that color on the pic above:makeout:

Dear God I can just see the clubroadster post.

"Can I haz 195/50/15 on the 15x10 6ul"

"Bro you'll have Mad stance yo."

*

Damn. Nice job Emilio.

Updates on delivery status?

delivery status? they havent been produced yet as far as I'm aware.

suppose to be here in August. I would think still two months out.

Assuming you didnt read the first post..."August delivery" Why put that if they haven't been produced yet?:jerkit:

Some last minute design tweaks delayed things a bit. Sometimes the FEA tells you its perfect but a weakness is uncovered in destructive testing. Microscopic suff you need dye penetrant and x rays to detect. Still made our weight target and the wheels will be bombproof. I'm happy. At the beginning of the year, we embarked on a project to make all the 6UL's stiffer, more bend and crack resistant. Raised the max load rating, updated the certification. The 15x10 is the first of what you might call gen 3.

Best guess is wheels arriving in my warehouse mid September sometime. The OGK is gonna look pretty intense with the 10's and 245's.

Care to share what the weakness was. Just curious. If you cant that is understandable.

hurry up I cant wait to replace my spinwerks wheels!

That I even share that we found a weakness is more than any wheel manufacturer will ever publish. That's enough info.

Getting world class strength to weight ratios for the 6UL is an iterative process. Designing and manufacturing a heavy wheel to pass is easy. The 8 and 9" 6UL variants were no different. Several iterations before we reached the targets we set for those Gen 2 sizes back in 2008. The 15x10 is effectively a gen 3 design. The things we experimented with and learned here will gradually be incorporated into the 7,7.5,8 and 9" variants.

Once upon a time I remember you saying that the Avon 245s were only good for a couple of track days at the most. Do I remember this correctly, or have things changed?

I only tested one set 5 years ago. It's a super soft tired intended for a 1300 lb car, no steel belts. I doubt they'll be any faster than a 225/45 Hoosier A6 on a 9. Tread life wise, you'd be better off with 225/45 NT01's on 9's.

When the new 245/40 DOT race compound radial hits the market early next year, it will be the tire to have for those that don't want to run 275 R6's but need more grip that 225/45 NT01's on 9's.