What I am always curious to hear is which tire was used on the car last. The
reason I ask is after 10-12 runs you really start learning the course and of
course you will have better times on your last runs. Was this part of the
factor?
Thanks
Kim Fine
#19 L1/DS
02 Subaru WRX
Date: Wed, 1 May 2002 17:39:12 -0400
From: "Ryan Jenkins" <jenkinrp@jmu.edu>
Subject: Kuhmo Ecsta V700 vs. Hoosier AS303 Comparo
>From the miata.net forums...
I had the opportunity to test the Hossier A3S03 against the Kuhmo Ecsta V700
at a Test & Tune event last weekend and thought I would pass along my
results.
The T&T was held at Grissom AirForce Base in Peru, IN on a smooth, concrete
surface. Air temps . were between 55 & 60 degrees, overcast with a dry race
surface. The test car used was a 99' Miata Sport with normal C-Stock mods
including RB 1 1/8" Front Bar and Koni Sports. Alignment settings were 1.4
degrees neg. front, 1.5 degrees rear. 1/16th toe out front, 1/8th Toe-in
Rear.
The course was approx. 40 secs long and featured two slaloms and several
mid-second gear sweepers. I ran 6 runs with each tire using the first run as
a
"warm-up" lap and then returning to the line. 6 to 12 minutes between runs,
roughly simulating a two driver car at a Divisonal or National level event.
Kuhmos:
The tires, even cold, launch and hook-up much better than the Hoosier under
acceleration. I had to use a very aggressive launch technique or lots of
clutch slipping to keep from bogging the engine off the line. The tires
comunicated well but, required relatively large slip angles to generate max.
grip. Braking performance was also very good and the limit was easy to find.
Hoosiers:
The Hoosiers need some heat in them to really launch well and even warm, I
found myself fighting excessive wheelspin with anything over 4500-5000 rpm
launch on this relatively cold day. The warm-up lap was pretty dicey with
lots
of understeer until about 1/2 of the way through the lap. Starting from the
second run on the Hoosiers grip level was noticeable higher and the
transient
response was exceptional.
Because of the lower rotating mass of the Hoosier and it's construction, it
is
more difficult to find and not exceed the tires max. braking ability.
Without
anti-lock brakes it is easier to lock-up and flat spot a Hoosier than the
Kuhmo.
Results:
Ok, enough analysis what did the timer say ?
Comparing the best two runs from each 6 run set, the Hoosiers averaged 1.1
seconds quicker. I was able to repeat my best times on each tire within a
tenth so I feel confident the results are vaild for my driving ablility.
A couple of things to consider, the Kuhmo's were heat cycled and run at full
(6/32nd) tread depth. Hoosiers start life at 4/32nds so some of the larger
slip angles and reduced transient response of the Kuhmo can be attributed to
this. Shaving the Kuhmo to 3-4/32nds would help and probably drop the run
time
by a few tenths.
I would also expect the gap to be narrowed on asphalt or dirtier surface
where
the Hoosiers compound generaly is not as effective.
Disclaimer: Your results may vary ! Please use this info. as one data point
in
your opinon of either tire.
Trent@TireRack.com
Kim Fine
Site Administrator
304-581-2663
304-581-2658 - fax
Make it a FISHY Day!
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