*Newbie Knowledge - Forget horsepower –it’s about grip.

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*Newbie Knowledge - Forget horsepower –it’s about grip.

Post by M20_fever » Tue Dec 13, 2011 6:44 pm

Forget horsepower –it’s about grip. Want to take a second or two off
your times – upgrade your tires. Can’t upgrade because of class rules?
Learn how to optimize them. There is probably more time to be
gained by the average racer in tires than any other part on the car.
Tires are your connection to the track and without good tires all the
horsepower in the world is useless.
Run the stickiest tires you can. There’s a wide range of difference in
performance “street” tires. One number you should look at is the
UTQG. Uniform Tire Quality Grade Standards (UTQG) was originated
to provide consumers with useful information to help them purchase
tires based on their relative tread wear, traction and temperature
capabilities. A lower number mean a sticker tire and unfortunately,
one that wears faster. For example:
There’s more to selecting tire than this number but it gives you a
starting point. If you’re a high speed autocrosser and you’re running
280+ tires there is likely time to be gained in new tires. Note that in
the GCR, tires with a UTQG of less than 140 will “cost” you 3 classing
points. That’s more than changing cams or running an open exhaust
(2 pts). There’s more to a fast tire than just the UTQG like sidewall
stiffness and other factors but these tend to be more a matter of
feel than something that can be measured. This is where you start
talking to other racers for feedback.
In wheel to wheel you may be required to run a certain tire. For example,
Spec Miata must run a Toyo Proxies RA1. In other classes you
have more flexibility. For many of us flexibility = tire budget. Hoosier
R6s are faster than Toyo RA1s. No disputing the fact. For me, the
cost difference is $160 versus $230 a tire. Beyond initial cost, it’s
important to understand how long the tires last. In R compounds you
need to think in terms of Heat Cycles. A heat cycle is when the tire
goes from cold to hot and back. Each practice, qualifying session or
race is a heat cycle. Some tires “wear out” heat cycle wise well before
they physically wear out. This doesn’t mean they can’t be raced on –
just they have lost their maximum grip. RA 1s are known for their
longevity and are less heat cycle sensitive. Hoosier are said to be at
peak for 12-16 heat cycles. Keep track of heat cycles. Some people
use a tire marker and market heat cycles in the inside of the tire. Many
race tire manufacturers / sellers have a “care and feeding” document
on their web site like this one at tire rack (http://www.tirerack.com/ images/pdf/war ... OOSIER.pdf). Read it.


note:mention of point assessments for Midwest Counsel, check your clubs GCR for equivalent assessments.
Midwestern Councel C Prepared class champion 2012
North Suburban Sports Car Club C Prepared class champion 2012
HSAX Instructor

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Re: *Newbie Knowledge - Forget horsepower –it’s about grip.

Post by ten2doyle102 » Tue Dec 13, 2011 8:39 pm

Nice little write up right there!
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Re: *Newbie Knowledge - Forget horsepower –it’s about grip.

Post by Rick » Sat Dec 17, 2011 1:01 am

Yes excellent points made. Tires/suspension/weight reduction and then HP last.
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