Dave,
You wrote:
>I am researching the purchase of tires and wheels. I am hoping I can get some
>advice on the type of DOT approved autocross tire we should buy for the season.
>
>
>The car is a FFR Cobra Replica, 2200 lbs with about 400rwhp.
>
>Between the new G Force R-1's, Kuhmo's and Hoosiers or others, what would you
>recommend?
KUMHO'S!
We, Steve Hobaugh and Myself, ran 2+ sets of Kumho's (274/40/17 and
315/35/17) on the SS Corvette in '99.. After the first couple of events,
when they are slow until heat cycled, they get better and better until, at
about 2/3 worn, they are at their best. From there till we've corded them
they have worked well with only slight "fall-off" near the end. On a mixture
of mostly asphalt but some cement surfaces, we also had very good life. On
the two complete sets we put on 4400 and 5100 seconds of run time, or 88 and
102, respectively, 50-second runs. The third set are heading for about the
same life. They also work well in the rain with close to full tread. For
comparison, the previous tire wear experience I had on my '85 Corvette was
with an number of sets of both 275/45/16 Hoosier Autocrossers (bias ply) and
255/50/16 BFG 230's. Both of those tires yielded between 2400 to 2800
seconds of run time which included switching the Hoosier's inside-outside
half way through their life.
Later in the '99 year, we ran a set of Hoosier, autocross compound, radials.
After getting acclimated to the different responses of the Hoosier's (you
can drive them "harder", compared with the Kumho's) we felt they were
definitely the faster tire, probably on all surfaces in the warm summer.
Also, from having previously run Hoosier radials on the '85, they are not
good in the rain. Additionally, probably because they don't have a steel
belt, I'm told they won't develop enough heat on cold/overcast days to work
as well as the Kumho's. However, we havn't yet run them, under those
conditions, to find out for ourselves. Surprisingly, to us, at about half
way through the shallower tread on the Hoosier's, it looks like they will
last as long as the Kumho's. I say surprisingly, because from the experience
with having run several sets of previous generation Hoosier radials on the
'85 several years ago, they didn't yield any where near the wear-life the
'99 tires are producing.
I don't have any personal experience with the BFG G-Force. But, from
anecdotal information, I've heard, that for many drivers, they are hard to
drive on the "fast-edge". I've also heard some complaints about wear rates
compared with the BFG 230's. A key indicator of tire preference is to look
at the tire brands run at the Topeka Nationals. According to entry lists, in
'98 the BFG (probably mostly 230's with possibly some "saved" 226's) were
the dominant tire brand in stock and SP classes (on 58% of all the entrys,
73% stock, 24% SP). In '99, Kumho (38% total,39% stock,35% SP) and Hoosier
(33%, 24% stock, 52% SP) both were on more cars than BFG (27%, 35% stock,
11% SP). BTW, the numbers on Hoosier's are somewhat mis-leading since, many
of the Hoosier's on SP cars are bias-ply autocrossers, not radials. Also, my
guess is that some of the BFG's in '99 were not G-Force', but previous
year's 230's. Interestingly, for some reason, the majority of good '99 BFG
performances were on front-wheel-drive cars, and only a few of the larger
and rear-wheel-drive cars ran BFG's. For the most extreem examples: In the
combined DS/ES/GS classes BFG's were on 92% of entrys in '98 and still on
60% in '99. However, in the '98 class BS, BFG's were on 87% of cars and, in
'99, only 10% were on BFG's, with 55% 0n Hoosier radials..
The "bottom line, as the accountants say, is cost. The Kumho's are
considerably less expensive than either the Hoosier's or BFG's. However,
since Kumho is in the process of bringing out a "new" tire this year, supply
of available "old" and "new" replacement tires may be tighter than in the
past.
For some of us the real BOTTOM LINE is which are faster. For that reason,
we're going with Hoosier's along with a couple different rain sets on the
side.
Don
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