I have used 275/40 -17 race tires (both Hoosiers and Kumho Ecstas) on stock 17 x 9 " rims and the results have been disappointing. The 9" wide rim is definitely too narrow to use the tire effectively.

So the obvious choice is to go to 315s on 17 x 11s but my concern is that the supply of 315s may dry up. I run my car in Solo 1 which means the average " run ' is about 10 miles with some practice sessions being significantly longer during a day leading to at least 100 miles over 6-7 heat cycles per day. This # of heat cycles ruins Hoosiers in short order. At tire rack the other 2 tires that come in 315/35-17s are the 032 Yo mamas ( which are too slow for competition use and weigh a ton) and my favourite Kumho victoracers which are fairly resistant to heat cycle degradation. Problem is the Victoracer is Kumho's "old" race tire and the new V710 is projected to have a significantly shorter track life.( The dreaded Ecsta V700 doesn't come in 315 sizes) Kumho is not answering my questions as to how long they plan to continue making the victoracer. Both Toyo and Hankook would be acceptable tires but come in 275s or 335 sizes.

At issue is that if I buy 17 x 11s will a 275 work that much better on an 11" rim that a 9 " rim to make it worthwhile? Would it be worthwhile to buy the sig cheaper and lighter 17 x 9.5 rims with a 36 mm offset thereby maintaining the widest track measurements or will this 9.5' rim only provide minimal improvement? OTOH surely a 275 on an 11"rim should be held very well, maximising contact patch.

 

I first ran 275 Victos on 17x9 wheels and like you thought wider would be better. I made the jump to 11" AFS wheels courtesy of getting very lucky on ebay and mounted the 275 Victos to those wheels to finish using up the tires. I thought the handling increase was very noticeable but I would say the 11" wheel is as wide as you want to go. The sidewall was bowed out to the rim. After a few track days I finally got some 315 Kumhos on the car and noticed another huge handling increase.

Don't forget the new 710 may not last as long as the Victos but in a 315 size they should be almost 10 lbs. lighter per tire and my understanding is they will cost about what the current Victos do.

 

I'm with Mike. While a 17x11 will definitely improve your handling over a 9" or 9.5" wheel with a 275, go ahead and maximize your handling by going to a 315.

I understand that Kumho is going to continue the V700's at least through this year and even make a few changes to them.

I know from a reliable source that the new Hoosiers have increased the number of heat cycles from around 10 to almost 16, a pretty significant increase.

Nevertheless, I'm pretty sure I'm going with V710's this year just because of cost.

I found this on Tire Racks site:
http://www.tirerack.com/tires/tires....del=Ecsta+V710

And unless it's a mistake, it's a 315/30-17 not a 35 series.

 

This is from the Tire rack site re the new 710s

"Achieving the best performance requires that fresh ECSTA V710 tires be used as their performance level will drop off after a typical race weekend’s use."

Seems like old Hoosier life expectancy or worse. This is why I am concerned re keeping a supply of reasonable 315s.

 

Yea, fast tires don't last long!! You'll still be able to get the V700's though, so if you're not concerned with the ultimate grip you can go with those... and they're cheaper!

 

You could also consider the Nitto 555 RII. They are coming out with it in the 315 size by this spring so I hear. I used them in the 275 size and thought they were a good overall tire and would last many heat cycles. They're also cheaper than the Kumhos IIRC.