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Keith
Keith SuperDork
2/2/11 11:05 a.m.

This sort of stuff is fun, so I'm going to open it up to everyone. Besides, I might get some good info

I need to figure out my wheel/tire package for the Targa. The event is a tarmac rally, with surfaces that range from smooth and perfect to "you have got to be kidding me" with loose gravel on top. Temperatures could be cool, and rain is quite likely. The Toyo RA-1 used to be the go-to tire.

The car is a V8 Miata making around 400 hp with an estimated race weight of under 2500 lbs full of peoples and tools. Miatas use a tire that's around 23" in diameter. Rules are that the tire has to be DOT legal and have 140 treadwear, but both wheel and tire sizing is free. Due to the rough surfaces at times, a bit of sidewall compliance would be pretty useful and the sidewalls will have to deal with a pounding.

Suggestions? I have a pretty good idea already, but I'll be interested to see what other people come up with from a clean slate.

Gimp
Gimp Dork
2/2/11 11:12 a.m.

StarSpecs come to mind first.

mndsm
mndsm SuperDork
2/2/11 11:24 a.m.

1 time use? RE-11's. I would probably drop a few wheel sizes and run a slightly wider sidewall, like a 50 series.

Maroon92
Maroon92 SuperDork
2/2/11 11:26 a.m.

Round ones...

If RA-1s will last then you could probably make any of the good street tire class Autocross tires work.

You are allowed to use 6 tires right?

ZOO
ZOO SuperDork
2/2/11 11:26 a.m.

Keith, I've got a few freinds who have been running Star Specs and/or RS3s in similar weather conditions in ON, with great success. As you know, October weather in ON is probably similar to early September weather in NFLD.

Not sure about the loose, gravel surfaces, though.

I've been running R888s on my M3 and Miata, but I can't say I am as pleased with them as with the old RA1. I might suggest the NT01 as an alternative to the ones above, but I don't know their treadwear rating.

EricM
EricM Dork
2/2/11 11:36 a.m.

RE-11 has decent wet traction.

mndsm
mndsm SuperDork
2/2/11 11:46 a.m.

I would have to agree with the *Spec in most cases. But if we're talking about what amounts to a single use tire, I'd figure on getting the softest/stickiest you can.

John Brown
John Brown SuperDork
2/2/11 11:48 a.m.

I believe NT01 have a 50 rating.

What did last years winner use?

Soma007
Soma007 Reader
2/2/11 11:49 a.m.

Toyo R1R, it is the tire for cooler/wet conditions in the SCCA street tire classes.

I'd pick the Dunlop Star Specs second, Bridgestones third. The Hankooks are fast but like a little heat to work their best.

Keith
Keith SuperDork
2/2/11 12:28 p.m.

I guess I didn't phrase the question right.

What tire and wheel size combination would you recommend as well as the tire?

Not all tires come in all sizes. This is a problem. Someone give me a 245/40-15 set of Star Specs, I'll bolt 'em on tomorrow

I ran the 205/50-15 RA-1 in 2008, tire wear was basically not an issue although I was running much less power and torque. We're allowed 8 tires (that changed in 2010 along with the treadwear rating) and the car has to have a legal tread depth at the finish line. About 1400 miles of driving, 25% of which is closed special stages that can include loooooong straights. None of the R compounds have a 140 treadwear rating unfortunately.

There's some good info here, and you're helping me refine what I think I'll have to run. But I don't want to say exactly what that is in case someone comes up with an option I hadn't thought of.

Interesting note: apparently Dunlop has to sell 10,000 of each size per year to turn a profit. My offer to buy 12 of the aforementioned 245/40-15 Star Specs was not sufficient.

92CelicaHalfTrac
92CelicaHalfTrac SuperDork
2/2/11 12:32 p.m.

^I'd buy 16 245/40-16 Star Specs, if that helped.

dsycks
dsycks Reader
2/2/11 12:37 p.m.

RA-1s are a decent thought and the best all around street tire I have used.

For what you are looking for however, the best ALL AROUND tire I have ever used were the original equipment Yokohama ADVAN A046s that came on the Mitsu Evo 8s. I could carve corners on tarmac and fully barn storm gravel and yump small single lane country bridges with uncanny poise and composure.

They will only last you maybe 5000 miles at most in hard use but may be the PERFECT tire for an event like Targa.

Sadly, they are only made in 235/45/17 so they may not meet your needs. If they do however, try and find some used on EvoM or some such place and try them out before you spend the cash on new ones. They cost but if I were running Targa they would be at the very top of my list.

John Brown
John Brown SuperDork
2/2/11 12:55 p.m.

Keith,

I will suggest 255/40r17 front and 335/35r17 rear on custom built Keizers with a set of bolt on fender flares...

Per Schroeder
Per Schroeder Technical Editor/Advertising Director
2/2/11 1:23 p.m.

225/45R15 R1R on 15x8s?

Per

Giant Purple Snorklewacker
Giant Purple Snorklewacker SuperDork
2/2/11 1:30 p.m.

TOyo RA-1s with a little "140" hand-written on the side

Keith
Keith SuperDork
2/2/11 1:50 p.m.

So far, I'm digging the last idea :)

25" diameter tires (235/45-17, 255/40-17) are tough to handle on a Miata. The extra ground clearance wouldn't be a bad thing, but I've found in the past that I've had to restrict compression travel on the suspension to make them work.

At $325/corner, I'm not sure I could justify the A046. But I have to admit I'd never considered them. That's the sort of thinking I'd love to hear.

Right now, I'm thinking the same way Per is. A 225/45-15 wrapped around a 15x8 wheel. Most Miata track guys would put this on a 15x9, but that makes a pretty stiff sidewall. Going 225/45-15 means I'm restricted to two tires: the Toyo R1-R and the Hankook R-S3. Given the comments here, it's looking like the R1-R would be the pick of those two.

If I went with the Star Spec, I'd have to go 205/50-15. I could use my existing wall of 15x7 wheels, so that's a big savings. But that's a pretty small tire for that sort of power/weight ratio.

ManBearSTIG
ManBearSTIG Reader
2/2/11 2:04 p.m.

Keith, I think the R1R would be right up your alley. From running them this year in STS, they like light weight cars, don't like too much heat, and are great in the rain. I matched time with Becker's CSP Miata, driven by McCabe, in the rain on a set of scrubbed in R1Rs. They were on Hoosier wets.

The sidewall, also, has a bit of flex in it. So should be what you want there. We would have to lead the car a bit in transitions, but once set in sweepers, they had tremendous lateral grip. I was really impressed with the lateral grip they gave. And the bit of flex they provided was always predictable, and easy to adjust to.

Only thing they don't like, really, is heat. Once hot, they take FOREVER to cool down. But that doesn't sound to be a big issue for you in this event.

Not really sure how they handle big power (acceleration grip), never had any! LOL.

Of course, this is all for the 195/50-15. Not sure if there is/was too much of a difference in compound between them, and the 225/45. I know there was between the 195 and the 205.

imirk
imirk New Reader
2/2/11 2:10 p.m.

Aren't you sponsored by 949? Will they let you advertise a set of 6ULs?

Autolex
Autolex HalfDork
2/2/11 2:45 p.m.

I came here to suggest what Per already did... R1R's on 15x8" (6UL?)

unk577
unk577 New Reader
2/2/11 2:48 p.m.

Rumor has it there are a set of Hankook RS3 225/45/15's on a L33 car returning some impressive #'s and continuing to hold up to the abuse.

DILYSI Dave
DILYSI Dave SuperDork
2/2/11 2:49 p.m.

I like the R1R as long as you don't overheat them. Which you may with that much power.

Gotta ask - Why limit yourself to the stock wheel wells? That's my biggest "problem" with V8 Miatas - I just can't see trying to put all that power through a 23" tall 225. Tub it and put some 315/35/17's in there!

imirk
imirk New Reader
2/2/11 2:51 p.m.
DILYSI Dave wrote: Tub it and put some 315/35/17's in there!

Yeah! you're in the "Unlimited" class :P

Keith
Keith SuperDork
2/2/11 2:52 p.m.

I'm not sponsored by 949 Racing, but I was planning to talk to Emilio for his take. He's good on this kind of thing as well.

I ran this by my contacts at Tire Rack, and they came up with the same suggestion - they don't sell Toyos, so their tire of choice was the Hankook "and be conservative in the wet".

I'll take another look at what I'd have to do to squeeze a 25" tire under the car. I got creative on Elvis a while back and made it work, but going back to 23" tires illustrated very nicely what I'd had to give up. Still, I can be a little more creative on this car than I was then and I can (have to) run a higher ride height. Unfortunately, it's a higher ride height that doesn't come with a matching increase in suspension compression travel.

NY535iManual
NY535iManual New Reader
2/2/11 3:01 p.m.

Keith - Do you have a build thread going for the Targa V8?

itsarebuild
itsarebuild Reader
2/2/11 3:20 p.m.

do they all have to be the same tire brand and size?

ie could you go with a very sticky set for the warmer days with the best roads and get another wet all season-ish tire to go thought the really wet days and possibly mount just before the finish line for the tread depth requirement?

i dont know all that much about the targa except the last televised one i saw had at least one day with major downpours....

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