Rules pages 55-56 TIRES

[mattd]

I guess the only question I would have is - what problem are we attempting to solve? Fixing a potential point rating issue with the BFGs and Hankooks as Stephen posted, or something else?

I am the only person in T40 to run Hoosier R7s (as far as I know) - How I ended up there is that I thought about chasing power and weight (even bought and subsequently sold at a loss several thousand dollars worth of power adders) but thought that trying a low power (and relatively high weight) Miata build that accentuated suspension and tire was the way I wanted to go. The fact that I am the Hoosier guy didn't result in me crushing T40 - in fact if you look at the results there is all kinds of diversity all season (except for one particular BRZ ) and super competitive results throughout. Subjectively, I am down on power based on how some of my competition pulls me on the straights - objectively I am down on power via the dyno pulls I did before I selected this strategy.

So...not surprisingly, I tend to agree with Jeff W "The tire is part of your build trade-off."

[TXBDan]

Seems to me like it'd take a lot of time and money to conduct accurate tire testing for points assessment. How do other sanctioning bodies do this? Can we get/use their data?

[Dtangard]

Here is the NASA breakdown:

A. TIRES:
1) The following DOT-approved R-compound tires: BFG R1S, Goodyear Eagle RS AC (auto-
cross), Hoosier A7, Hankook Z214 (C90 & C91 compounds only), Hoosier Wet DOT (if
used in dry conditions—see section 5.6) +22
2) The following DOT-approved R-compound tires: Hoosier A6 +17
3) The following DOT-approved R-compound tires and those with a UTQG treadwear rating of
40 or less not listed otherwise in these rules: BFG R1, Goodyear Eagle RS, Hankook Z214
(C71, C70, C51, C50), Hoosier R7, Kumho V710 +10
4) The following DOT-approved R-compound tires: Hoosier SM7 +9
5) The following DOT-approved R-compound tires: Hoosier R6, Hoosier SM6 (note:
Continental Tire Sportscar Challenge EC-Dry tires (225, 245, 275) OK) +8
6) The following DOT-approved R-compound tires: Toyo Proxes RR, Hankook TD,
Pirelli Trofeo R +5
7) The following DOT-approved tires and those R-compound tires with a UTQG treadwear
rating over 40: BFG Rival S, Bridgestone RE071-R, Maxxis RC-1 (examples: Kumho V700,
Kumho V720, Michelin Pilot Sport Cup & MPS Cup 2, Nitto NT01, Pirelli PZero Corsa,
Toyo R888, Toyo RA-1, Yokahama A048, etc.) +4
DOT-approved (non-R-compound) tires with a UTQG treadwear rating of 120-200
(examples: BFG g-Force Rival, Toyo R1R, Dunlop Direzza Sport Z1 Star Spec,
Bridgestone Potenza RE070, Kumho Ecsta XS, Yokohama Advan A046 & Neova AD08,
Hankook R-S3) +2

[jeffw]

Keep in mind a NASA point isn't the same as a COM point.

[peejay]

Interesting that NASA puts the RE-71R(200TW) and BFG Rival in the same bucket as a NT01(100TW). Sounds like I picked the wrong "do all" tire.

[SandyClam]

Keep in mind a NASA point isn't the same as a COM point.

Certainly, but it's interdasting to see how they group the tires.

[dinoracer]

Why not lower points for the lesser tires rather than raise the points for the faster tires? Thus giving the cars running slower tires other options to drop the times. Once you have gone to purple crack you never want to go back LOL.

A few points back to folks in the same class on a lesser tire probably won't mean much. They don't want to spend the money on Hoosiers, and they probably can't make to many more changes to their more mild race car or street car to compete.

Paul G.

I’ll take those points, i can think of a bunch of things I could do with them.

We had a good discussion in the Rules committee meeting the other night, everyone should stay tuned on this subject as we continue this discussion both here and in committee.

[paultg]

Why not lower points for the lesser tires rather than raise the points for the faster tires? Thus giving the cars running slower tires other options to drop the times. Once you have gone to purple crack you never want to go back LOL.

A few points back to folks in the same class on a lesser tire probably won't mean much. They don't want to spend the money on Hoosiers, and they probably can't make to many more changes to their more mild race car or street car to compete.

Paul G.

I’ll take those points, i can think of a bunch of things I could do with them.

We had a good discussion in the Rules committee meeting the other night, everyone should stay tuned on this subject as we continue this discussion both here and in committee.

I'm not saying i won't take them ; just not sure what it will really mean if up against a car on Hoosier H20s or R7/A7s still. Whatever you guys come up with it will be fun to watch how things shake out next season.

Paul G.

[SandyClam]

A few points back to folks in the same class on a lesser tire probably won't mean much. They don't want to spend the money on Hoosiers, and they probably can't make to many more changes to their more mild race car or street car to compete.

Paul G.

I’ll take those points, i can think of a bunch of things I could do with them.

We had a good discussion in the Rules committee meeting the other night, everyone should stay tuned on this subject as we continue this discussion both here and in committee.

I'm not saying i won't take them ; just not sure what it will really mean if up against a car on Hoosier H20s or R7/A7s still. Whatever you guys come up with it will be fun to watch how things shake out next season.

Paul G.

So does this mean you are going to drive next season?!?

[paultg]

Whatever you guys come up with it will be fun to watch how things shake out next season.
Paul G.

So does this mean you are going to drive next season?!?

I did say "watch" but I do hope to be at some of the events, and to be driving.
I keep plugging away at the new job so we shall see how it goes come spring time.

[6PAK72]

FWIW, having driven NTO1 and RA1 back to back, the RA1 is a superior tire under both initial grip and heated grip - at least for the weight (2500) I’m running.

The NOT1 is a dog. I’d rate it with the BFG.

I’m also on the fence about the R7 vs. the SM7 vs. the A7. I ran SM7 and R7 back to back last season several times, and I don’t think the R7 is the advantage that some think it is. The A7 may heat faster, but in hot weather, it’s definitely not faster than the R7, and may be slower than the SM7.

There's a tire selection/driver selection deviation here, for sure, but I think the R and the SM are a lot more similar than our points call it.

[paultg]

FWIW, having driven NTO1 and RA1 back to back, the RA1 is a superior tire under both initial grip and heated grip - at least for the weight (2500) I’m running.

Humm, I've experienced the opposite with my '91 which was 2400-2450 lbs. I prefer the feel of the NT01 on the car; it seems to just perform out of the gate until done. With the same size RA1 they were squirmy at first until the tread wears down (so they don't feel as good for a bit); and I don't think I was ever faster on them when comparing to the NT01. I really think they are the same tire, and it's a matter of preference on what feels good to the driver. But give the NT01 more points back.

Paul G.

[6PAK72]

forgot to mention the RAq was shaved.

[SandyClam]

Shaved RA-1s are way different than full tread depth, fo' sho'. In fact, I swear they get faster (at least, they used to anyhow) the more you run them, with the absolute best grip *right* before they cord. And the cords have decent grip, too!

[6PAK72]

Agree. Last weekend of the season at Palmer, the RA1's were getting me mid-1:49's. The SM7's get me the same number. RA1 is a wonderful tire - so wonderful I think it needs a point or two above the NTO1.

Anyone have any feedback on the R888R?