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Need experienced circuit racers' opinions regarding tire sizes

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Old 09-01-05, 02:05 PM
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Danny Popp of ASP fame runs 18s on the front and 17s on the back of his Z06. It is just something you have to work on for your application.
Old 09-01-05, 02:18 PM
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Originally Posted by finky
Danny Popp of ASP fame runs 18s on the front and 17s on the back of his Z06. It is just something you have to work on for your application.
That is to run a 285-30-18 up front due to it being shorter than a 275-40-17. Then run a 315-35-17 in back. Carl
Old 09-01-05, 03:28 PM
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I SEARCHED

Anyone have a pic of a chunked tire?
Old 09-01-05, 03:42 PM
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Originally Posted by DamonB
I've driven on many tires and I've helped and instructed many drivers on many tires. No ifs ands or buts about it, beginners learn more by starting on street tires. They are much easier for the beginner to understand because their level of feedback is slow and honest and allows them to really feel what the tire is trying to say through the car. Sure they'd go faster around the corners if on race tires but they'd be terribly under driving the car because they don't understand how the tire communicates with them in different situations.
That's exactly what they told us at a track driving school that I attended.

Originally Posted by peejay
also disagree with using street tires on the track. They are NOT cheaper than R compound tires! I have seen street tires destroyed during an open track event, in less than one day. They cannot handle the heat, and so they chunk and basically the tread comes apart.
In my experiences using fairly poor tires on a course known for destroying tires (lowish speed), you're only going to get about a day out of street tires if you're on for say 6 hours total. Guys like 23racer and 01racer have said that they only get one race per set of R compounds whereas they can run a whole bunch of races/days at Mosport. I'm sure they're loading the tires more, but on the same token their superior driving style and ability likely equalizes much or perhaps all of that difference.
Old 09-02-05, 12:08 AM
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Originally Posted by finky
Danny Popp of ASP fame runs 18s on the front and 17s on the back of his Z06. It is just something you have to work on for your application.
Popp's setup is that way for other reasons. R-compound tire selection has dictated that particular choice. The 30-series tires available in 18" sizes have better transition and turn-in response than the 35- or 40-series tires available in 17" sizes. Like wise for the rears, the 35-series 17" tires provide better traction than the 30-series 18" tires.


I'll join in on the bandwagon for street tires .... you always know when you've exceeded the limits on street tires. That's not always the case with R-compounds ... as mentioned, they tend to mask a lot of driver errors. Furthermore, R-compounds push the car harder ... meaning you'll need to start thinking about brake pads, fluids, engine cooling, etc. Anyhow, my advice would be to stay on street tires until the car and you are one. Tire sizing is irrelevant until you're able to consistently drive at the limit on track.
Old 09-08-05, 12:13 PM
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my two cents

1) I'd run the widest tire I could fit on the stock wheel - 245/45/16

2) As an experienced track rat, instructor, and racer I can say with great confidence that a street tire is going to be easier to learn (& recover on). They "communicate" a lot more and they lose grip much more gradually than r-compound tires. If you plot the grip vs slip angle curves, the grip level on an r-compound tire is much higher, but drops off fast. Anyone who has pushed the limits on a set of Hoosiers knows what I am talking about.

That..and if you go off...you'll be going 5-20mph slower. That can make a big difference on the outcome

3) Any new driver destroying a decent set of performance-oriented street tires in a day is probably driving way over their heads.

- Phillip
Old 09-08-05, 01:37 PM
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Originally Posted by itr_hybrid
3) Any new driver destroying a decent set of performance-oriented street tires in a day is probably driving way over their heads.
Meaning what, overdriving? That's probably fair criticism, but the word "decent" probably didn't apply in my cases.
Old 06-01-06, 12:07 PM
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hello all!

well i just took my FD onto the track for the 1st time. again, it's a bone stock FD w/ only eibach springs, running on crappy 4 season goodyears. MAN! all she wanted to do is understeer!

I've been trackin for years, all kinds of drive, but this is the first time w/ an FD. I've tracked an FC for 2 years, w/ bone stock suspension (20 years old), rear-toe eliminator, and s-03's. and its behaviour was EXTREMELY predictable; the *** would start to come out everytime i trail brake a little too hard. very easy to drive.

the FD, on the other hand, always understeered during turn in. mind you, the track i was on is mostly slow, tight, honda-style turns. but i couldn't believe how much the FD wanted to understeer during turn in. Is this normal? have any of you been on the track w/ a bone stock FD running on 4 seaons?

btw, my FD is a 93 touring.

Thanks guys!

Howi
Old 06-01-06, 01:16 PM
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Originally Posted by Howi
hello all!

well i just took my FD onto the track for the 1st time. again, it's a bone stock FD w/ only eibach springs, running on crappy 4 season goodyears. MAN! all she wanted to do is understeer!

I've been trackin for years, all kinds of drive, but this is the first time w/ an FD. I've tracked an FC for 2 years, w/ bone stock suspension (20 years old), rear-toe eliminator, and s-03's. and its behaviour was EXTREMELY predictable; the *** would start to come out everytime i trail brake a little too hard. very easy to drive.

the FD, on the other hand, always understeered during turn in. mind you, the track i was on is mostly slow, tight, honda-style turns. but i couldn't believe how much the FD wanted to understeer during turn in. Is this normal? have any of you been on the track w/ a bone stock FD running on 4 seaons?

btw, my FD is a 93 touring.

Thanks guys!

Howi
Doesn't sound normal to me, the first 3-4 times I went to a track in my 93 touring I was on 7 year old uniroyal tigerpaws. As far as I remember its balance was pretty much the same as on my current set of yoko a032r's and my hoosier rs04 (or whatever the number is). I have to be really heavy on the brakes way too late to get it to understeer, otherwise it tends towards oversteer in almost all conditions.

Have you had it aligned to common specs and checked your tire pressures?
Old 06-01-06, 02:27 PM
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I haven't run with (suck-in-)all-season tires on the track, but with Bridgeston S02-PP's (245/45r16) and stock suspension and power, my car has always been fairly neutral.

I wonder if the fronts were getting greasy from hard braking and turning - was the course fairly tight?

You said that you had Eibach springs? What rates were you using F&R?

-bill
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