I've always wanted to try a set of slicks. These should be a decent step up from the 225 nt01s. Hopefully they last more than a few sessions. Anyone drive on a set of r80 or r100s?

 

I'm curious as well. I'm sure you saw Dean's comments over on m.net.

Let us know how they hold up, once I finish stuffing the V8 in my car I want to give those slicks a try.

 

You're an *******.

 

Seriously, **** you, I hate you, I want those.


Based on the reading I did a while ago on Porsche forums, you should expect to get ~7-8 cycles out of them, they won't get greasy when it gets hot, and they are god damn fast. Like, 1 second faster than a Hoosier A6, so 2-3 seconds faster than an NT-01.

 

This is why you get hit with 30 points for these in NASA

 

Awesome! and I was excited to finally be picking up a set of A6's... you bastard

 

I would like to know how those work out as well. Looking at the NASA TT rules though they are not even an option for me since they add soooo many points to my car that I would have to add more than the allowed ballast limit to keep from breaking out of my class.

 

I have those tires now. When I spoke to hoosier they said it was designed for a 8" rim for some class that I can't remember. They said 9"s or 10"s would be ok. Based on specs the 9"s are a better match. Hoosier states for optimum performance stay within a 1/2" of thread width. The thread width for the 245's are 9.4". I have them mounted on 9" rims and they fit perfect! I was going to run the 275 R6's on 10" wheels but after testing the 245 R80's at Infineon we found that they were 3 seconds faster than the 275 R6's (near the end of life) on a V8 Miata. The 245's on a 9" wheel needs only a 5mm-8mm spacer for the front so fitment is easier too.

According to my research the R100 tires have similar life to R6's. R80's slightly less than R6's but more than A6's.

 

After putting about 5 hours of track time on my nt01s this weekend and nearly finishing them off, I'm having second thoughts on waiting for the 15x10s to try the r80s. That, and the r80s smell awful and my garage stinks now. I wonder if I'll have to pull my 95's fenders for 245 on 15x9.

 

I see no advantage going to a 10" wheel vs a 9" for the 245 Hoosier. If anything it will be a disadvantage because it will pull the section width 1" wider increasing frontal drag.

For optimum performance Hoosier states tread width +- 1/2". The 245 at 9.4" is a closer fit to a 9" rim verses a 10" rim. Add to the fact that Hoosier told me they designed it for a 8" wheel makes the 9" a no brainer. I live in the San Rafael if you want to see how they fit in person.

 

Thanks. I decided to go ahead and get them mounted on my 15x9s later today. Now I need to convince Dean or someone else to heat cycle them during a session since I won't be at the track for a while.

 

LOL....Dean would love to he is the one who heat cycled mine and compared them to the 275 R6's.

 

Got them mounted up today. They all wanted the weights on the outside which is annoying because my caliper gets real close. After trying to decide on whether to flip the tire or put the weights on the lip or in the middle of the wheel I let the shop put them behind the spokes since I'm using a 5mm spacer. If they don't fit I'll pull them off. The tires are nice and light. Looks like they save around 4lbs each give or take some because of the lack of precision and other variables (silver gen2 15x9 w/ hoosier vs bronze gen2 15x9 w/ nt01 vs moderately worn nt01).

 

I have been seriously contemplating building a new car and eliminating my street drivability requirement. It would be an NA built around 23.5 X 11 R16s. or maybe 23.5 X12 R 16s. A track beast that also wouldn’t make many compromises to run in Solo in XP other than retaining a lexan windshield. They are only 1/2 “ bigger diameter and but wider. Seems about right. I know they work well based on seeing Ron Bauer running them on his NC DP Miata that will likely redefine how fast the DP class is.

This car Im thinking of building would incorporate tubbed inner fenders and most likely drop spindles. A seriously well thought out cage integrated into a structurally lightened chassis Simi tube frame maybe move some stuff around to optimize weight distribution. I’m getting some take off tires in a couple weeks to start playing with and am sort of looking for a cheap mostly straight chassis to start hacking on.

Bob

 

I think I'd rather have 1" of "stretch" than 1/2" of "stuff".

 

You would rather have 2" of stretch vs 1"? Hoosier designed the tire for a 8" rim.

 

You've left this part out the last couple of times, and it's fairly important. If Hoosier designed the tire to fit and work on an 8" wheel because that's the max width for a racing class (taking a shot in the dark here - SCCA T3), it doesn't mean that the tire won't work better on a wider wheel. Hoosier's recommended width range is 7-10" for that tire, the tread width is 9.4", and tires pretty much always work better with a very slight stretch. Just looking at Mike's photos it's pretty easy to see that there is some sidewall bulge with the 245 on a 9" wheel, and I'd put down on it being faster on a 10" vs a 9" wheel.

 

They definitely have some bulge in the sidewalls. I can get better pics of it tonight when I see how they fit on the car.

My thoughts are to break them in on the 9s and maybe put 1-2 sessions on it and then move to the 10s when they get here. The 9s should be an easier fit on my NA so that gives me some time to pull the fenders.

 

Bob that sounds like it is going to be a seriously fast car if/when you build it. Holy sh...

 

Will it be stiffer on a 10"? Yes. Will it be faster than 9" wheel? I don't think so when talking about stock bodywork. That extra 26mm will be hanging on the outside if the car exposed to air. It's going to come down to the lessor of evils. I feel the 245 is better suited to the 9" rim on a stock body. The only way to find out is for someone to do the back to back testing.