Originally Posted by Rebelracer568
Think im going to try some ra-1's they grip well and have pretty good life.
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Toyo makes some of the worst R compound tires around. Seriously - ask any racer who is stuck using them in a spec or tire spec'd class (CMC, AI, Spec Miata, etc). The only racers on Toyo tires are ones that
have to be on Toyo tires. I have been labeled a "Toyo Hater" by some, and I was even tricked into buying a set of Toyo R1Rs on our Mustang (shown below). Horrible pieces of sh!t that had terrible grip and horrific wear. They were the slowest in our private tire test in May 2011.
The RA-1 makes about the exact same grip as many of the modern 140-180 treadwear "Extreme summer" tires but has worse wear. I've tested RA-1s back to back against Yokohamas, Bridgestones, Hankooks and others, with data logging and timing equipment, and they were not any faster in any measure except wear. We raced in Street Touring classes for years, and would often switch to R-compounds at events to see back-to-back differences. We tried RA-1 tires on 2 different occasions, but were faster on street tires. We have done many tire tests over the past decade. RA-1s are at the bottom of my "recommended tire list".
The very very bottom.
Now, autocrossing comes down to two main things: weight and tires. For the most part you cannot lower weight from an S197 enough to make a radical difference in times. These are big, heavy cars, and we're pretty much stuck with 3400-3600# curb weights. But we can do something about tires. My advice: GO AS BIG AS YOU CAN AFFORD. You can never have too much tire in autocrossing, or tracking, in an S197.
The widest wheel that easily fits these cars front and rear is an 18x10, with the offset around +43 or so. Anything wider either A) doesn't fit or B) will need different front and rear offsets. And by "fit" I mean it fits under the stock fender contours. Vorshlag pioneered this fitment several years ago.
Kumho V710 R-compound tire in 315/35/18 on Forgestar F14 in 18x11" on 2013 GT, lowered 2.5"
One of the more popular set-ups we sell lately is an
18x11" Forgestar for $350/each. It is light, it is very wide, it is the proper diameter (18" - just big enough to clear the 14" brakes, and nothing more) and it fits under the stock fender contours with nothing more than a little negative camber up front. These will not rotate front to back and have significantly different offsets on each axle.
305/650/18 Continental Slicks on a 11" forgestar F14
These 11" wide wheels will work well with a 285 to 315mm wide tire. One of the popular sizes to use with it is the 295/35/18, and another is a 315/35/18. Not a ton of choices in those two sizes, but there are some good ones.
http://vorshlag.smugmug.com/Projects...heel-teesting/
The gallery above shows some of the wheel and tire testing we've done on S197s. Dozens of different wheel brands and widths we have tested, including wheels we had custom built to fit these cars. That 18x10 ET43 came from us, on a run of wheels we made 100 of to get them out there, which everyone later copied.
We've stepped up to a 18x12" wheel on both ends on our TT3 Time Trial Mustang, and flared the fronts for use with up to a 335mm tire. We usually still run on 315/30/18 Hoosier R6 or A6 tires, though, as they are much more common and easier to get. Plenty of grip. For a mostly street car I'd use a ~180-200 treadwear 275/40/18 on an 18x10" and be happy.
Note: the 18x10 "drift" wheel is a cheap and
super heavy wheel that is shunned from virtually all S197 racers. Absolute boat anchor wheels... but they are super cheap, so street guys flock to them. Not racers - way too heavy. Adding rotating inertia like this is extremely detrimental to competition use.
Cheers,