Ok so getting my plan together for the spring. I run a slightly modified miata in NASA time trials. Nothing real crazy just built engine and other bolt-ons, no boost or anything quite that much. Anyway, I am trying to figure out which tires I want to run. I currently have hankooks z212's and they are just ok in my opinion. I have enough room within my class rules to run either NT-01's or toyo ra-1's. Although I keep reading about the new kook RS-3's and how they are much faster then the 2's and are supposed to be equal to NT's!? Now for the real question, how much faster would a full on race tire be vs. my RS-2's or even the new RS-3's. I am planning to run 225-45-15's. Does anyone have real data, not just opinions? I keep hearing two seconds sometimes three, but no one can tell me, yes I tried those and they did this! The tires don't need to last forever or be driven on the street. I am just looking for a good consistant fast tire that won't bite me to hard when I run out of talent.
Thanks for the help
Paul
Guess what's in the February 2010 issue of GRM?
"—Comparison of R-compound vs. street tires: What's the real difference these days? "
Ahhh, Keith you always give me something to look forward to! 
Damn it come on February...
I don't have real data that is comparable directly because of the time and other modifications between sets but I have used both the NT-01 and RA-1 in the size you are looking for. So, hard lap times aside they were pretty close, favoring the NT-01.
The NT-01 can be run pretty fast right out of the box without shaving because its tread design has huge blocks. I also think its why its a faster tire by a small margin - it puts more rubber on the road over its whole life. The RA-1 doesn't do that even when its shaved to 3/16ths until after a few sessions. So, when I was comparing the two the NT was quicker but the comparison was a different stages of tire life. I think 2 laps before they both cord they would be dead even as they both get quicker all the way to the cords. The two tires otherwise behave similarly (and they are the same compound so thats no surprise).
They don't bite, they come right back after you push them over the limit and they are long lived. They like a pretty wide slip angle which freaks some people out.
I'd buy the NT over the RA unless I was racing in the wet because I think its faster for longer of its overall lifecycle and its the same price. The RA-1 gets rid of water better but IMO that is its only advantage.
For the record, I did not like the 212s either - they were greasy and fickle to get the pressures right for their whole lives.
Someone in our club had the same question. Just bought RA1's and had the kooks. We run a fast autocross at a kart track. On the same day he hovered around 60 seconds with the kooks and with the RA1's unshaved he dropped to high 57's. This was in a mildly modified miata on a track we've used a ton, and had plateau'd at 60 seconds with the kooks.
As a club we figure the ra1's are worth 2-3 seconds at this ~60 second track versus even the newest breed of street tire(like the RE11, reo1r, dunlop star specs etc.).
I'm itching for the RS3s to come out in the size that i need.
I LOVE my RS2s, and i'm not sure if i can imagine what the improvement would feel like if it's as big as everyone is saying.
Of course, keep in mind that i'm on a hugely "over-tired" car, if that even exists.
How serious are you? From your post you sound to be more interested in having fun than that last 0.00000000000000000000000000000000000000000001 of competitiveness. I made a decision a few years ago, swapping R comps on and off at events was fine when I was 20 something, but being the cool side of 40 means one set of tires for road and track. Less work, less hassle, less time, less dirt, more fun for me :)
Keith wrote:
Guess what's in the February 2010 issue of GRM?
"—Comparison of R-compound vs. street tires: What's the real difference these days? "
Yep. And some guy named Andy Hollis did the driving. It's a good piece.
Adrian_Thompson wrote:
How serious are you? From your post you sound to be more interested in having fun than that last 0.00000000000000000000000000000000000000000001 of competitiveness. I made a decision a few years ago, swapping R comps on and off at events was fine when I was 20 something, but being the cool side of 40 means one set of tires for road and track. Less work, less hassle, less time, less dirt, more fun for me :)
Well there in a nut shell is my problem! That was my idea when I first bought the Z212's. One set of good tires not having to change them and so on... A good tire that might be a little off pace but close. Then it seems I am still off the pace about two seconds, and well the inner schumacher is gnawing at me. When I race I really do intend to win or at least have a shot. Not at all costs mind you, but just driving around isn't as much fun anymore. Thats kind of why I am hoping the new RS3's will be all they are hyped to be. If I can still run one set but be much closer to the r-comp times, i'm good with that. But if they aren't well then I guess r-comps are going to be a reality.
At my last event I was just under 2 seconds slower than the winning spec miata time. Car prep is similar with almost the same suspension, a little more engine, same brakes. The only real difference was the tires. I use spec miata times as the barometer since the guys who win in my region are usually SM guys who are also running TT.
"David S. Wallens said:
Keith wrote:
Guess what's in the February 2010 issue of GRM?
"—Comparison of R-compound vs. street tires: What's the real difference these days? "
Yep. And some guy named Andy Hollis did the driving. It's a good piece."
David any clues to the outcome? Don't worry we will all still by the mag, at least untill there are no more trees!
The way the dates on the magazines go, the Feb issue should be in the mail pretty soon anyway, right guys? I mean, I seem to recall getting an October issue in April or something like that.
I'm also in the middle of a tire buying spree. Rolla, Esprit. I'm thinking ZE912's for the Rolla, at $62/ea delivered from DiscountTireDirect. The snow tires are about to go on, so I have a few months to decide yet.
Feb 2010 mails on Dec 15, hits newsstands Jan 5. Basically, the month on the magazine is the LAST month it's available so you don't find a January issue on the stand in late February. With GRM's 8-issue year it can get a little weird.
http://grassrootsmotorsports.com/media/files/2010-grm-media-kit.pdf
Keith wrote:
Feb 2010 mails on Dec 15, hits newsstands Jan 5. Basically, the month on the magazine is the LAST month it's available so you don't find a January issue on the stand in late February. With GRM's 8-issue year it can get a little weird.
http://grassrootsmotorsports.com/media/files/2010-grm-media-kit.pdf
ok so only 49 more days till I get my issue. 49 48 47!!!!
Hess, the ZE912's are a darn nice tire. We put a set on my dads daily driver miata and I have them on my focus zx5. Quite, good ride, and yet handle well and give good feedback for an inexpensive street tire.
Now if I can only get David to crack a bit with some good data I can take a nap before I have to pick the kids up
I have the same / similar question... my 91 CRX runs on RE01's for auto-x (195 50 15's) I've been using a set of Azenis RT-615's on track (205 50 15's) even with their tendencies to get greasy as they heat they've done fine... a friend now has them... the question is what next...? go to 13's ( hoosiers 225 45 13's) like most CSP cars (where I would be for TT) or 14's like I saw on an OPM ITA CRX this past weekend or 15's like "paulmpetrun" was asking about..?
any opinions ?
