Racing Tire Recommendations, Please

[trs]

toyo RA-1.

Apparently quite similar to the kumho V70's.

I also read a rumour on an american autocross board that the Falken fk451's are made from the same compound as the more expensive falken azenis rt215. By shaving them prior to trackwork you have a sticky tyre available in a whole bunch of sizes.

[5523]

I used both the Kuhmo Victoracer and the Toyo RA1 Proxes when I ran Spec Miata in Texas. Both tires seemed to perform well but there were definite trade-offs between the two. Kuhmos had a slight advantage in producing lower (better) track times probably because they heated up more quicly. The Toyo was less costly and lasted much much longer. On my 240Z ITS I run the Toyos because of price and durability and the hit to the wallet is far less when you need to buy only 2 sets of tires for a season versus 4 sets.

The slight performance advantage of the Kuhmo won't be realized with my skill level for another season or two anyhow.

Can't speak to the strengths/weaknessness of the Hoosiers.

Mike

[Brett240]

I ran the toyo RA-1 for a full supersprint season last year. they have issues when brand new, those tread blocks squirm around like crazy until they are worn down.

once the tread is worn down i found them pretty consistant through several races. they held their grip level up pretty well when compared to Yokahama's and bridgestones which lose their grip after a few races. (although these tyres had more grip and a softer compound then Toyo's to begin with)

[260DET]

Agree with Brett completely re the Toyo RA1, they do seem to be able to maintain their grip level through many heat cycles. Its a pity they have that blocky tread pattern though, it may be good in the wet but in the dry when new much sideways action, which then risks overheating and buggering them forever.

[SuperDave]

Agree with Brett completely re the Toyo RA1, they do seem to be able to maintain their grip level through many heat cycles...

I have a set of Proxes that have been idle for 8 years! They were brand new (shaved) but I blew up and haven't been back on the track since. How do you think they'll perform when I get them back out sometime in the next year? I wish I had packed them in nitrogen, but no, they've been in the attic and on a shelf in the garage the whole time.

[Brett240]

Old go karting trick - soak them in brake fluid for a while and they will soften right up. of course i cant account for the condition of the tyre carcass and how it will hold up on the track.........

[boltmans]

I haven't tried the Toyo's yet, but I did run both Kumho Ecsta V700s and Hoosier R3S03's (no longer available) last year during my rookie season and here is a brief dissertation of what I thought of them. I started with full tread depth heat cycled Ecsta's on a gamble that it would rain or be cold during drivers school, well it was sunny and hot, needless to say they were abused. I ran them two more weekends abusing them worse trying to find correct tire pressures. I then bought a set of shaved and heat cycled V700's. Dropped 1.5 seconds off my times without a setup change. After the 6th heat cycle on two tires, the tread splices started to split (one completely across the tread about 1/4" deep) and the the worse of the two also chunked :mad: . These tires were not abused, I had tire temps and pressures well within the range that Kumho recommended. They warn that this would happen to Full tread depth tires if you abuse them, so I am not sure why it happened to not shaved non-abused tires. Grassroots magazine did an article on this and says its OK as long as you keep an eye on it, but I don't trust that since I can't watch the tire splice as I am driving. Me and my car are worth too much to make that gamble, especially when the price for shaving and heat cycling is same as the price for the 03's.

Then switched to Hoosier 03's for last two races. dropped another 0.8 off my times. I was still adjusting the setup and getting used to the tires at the end of the season so I don't have any comments about number of heat cycles yet. Since the 03's are no longer available, not sure how good that information is as the rumor is that the '04s are better all the way around.

Take this info FWIW since it was my rookie season, Also I still have my original tires that have 20+ heat cycles that I use as backups/intermediates.

Bret

72 ITS 240Z

73 240Z

[260DET]

Didnt Kumho withdraw those V700's from sale for a while due to problems like you describe Bret? So your experience is that they are quick but fragile?

[boltmans]

They pulled the new V710's not the V700's for tread splice issues. The V710's are the Hoosier look-alikes.

My experience is when shaved they are quick espicially the first couple laps, but my belief is that Kumho has developed some quality issues. People used to claim that they would get 20+ heat cycles without any problems and now enough people have had problems that an article gets written in GRM, that's a little fishy. I am also a little sour because I tried contacting Kumho to volunteer my tire data and see if it was something I did, and they responded a month later with a name and number to call and after 10+ polite voice mails still no contact. I made it clear that I wasn't looking for freebies or anything, I was just after an understanding of the root cause of the problem, I guess that is the engineer in me...

That being said my tire choice for this year is to stick with the Hoosiers and live with the cost/durability. If cost were no object, I would get a set of the Goodyear DOT's and upgrade to 15"wheels to try out the Avon's.

If I were to go back to one of the cheaper tires I would be trying shaved Toyo RA1's.

[mayolives]

Check out Michelin's Pro Cup. They are fast, soft, DOT and last much longer than Kumho Ecsta V700, Hoosier R3S03, and most other racing tires. They are not inexpensive.

[SuperDave]

Old go karting trick - soak them in brake fluid for a while and they will soften right up. of course i cant account for the condition of the tyre carcass and how it will hold up on the track.........

I will check out the brake fluid softening trick. It would be cheaper than the commercial softeners.

The recent news about the dangers of older tires gives me pause, though. The rubber obviously breaks down or gets brittle over time. These older tires should be fine for autocrossing and maybe even solo I, but I might hesitate using them in a road race where they would really get hot. They are in excellent condition otherwise.

[sopwith21]

Keep talking, guys. This is really helpful and appreciated. I'm still researching, but I'm leaning toward the Kumhos or Toyos... probably the latter though my mind is still open. The Hoosiers are expensive and wear so much faster that I'm a little scared of them. I do need a full slick if possible. Dropping from 10 inches of rubber down to a DOT will cost me a considerable amount of time... more than two seconds off my lap times and I'm not going to be competitive in this class. So a full treaded tire may not be the thing for me.