Getting this back on topic...

54 entries in '10 Nats for STX, and only 6 RX-8s with 7 drivers.

I'm used to being in the majority when I drive a Mazda at a national event. I guess we'll see what kind of smack-down occurs.

 

Yeah, I thought there would be alot more of us out there in the STX field this year, seems like alot of people are still in the development stage, while the BMW's have been here for a while.

 

Yeah, I'm still way underprepped to consider making the trip. Next year...

Best of luck in Lincoln folks. It's nice to see STX leading the ST classes with the highest number of entries!

 

Thanks, Chike.

Has anybody read the latest GRM? They tested 3 sizes of Star Specs on their STR MX-5 project car, and the lighter, narrower, shorter tire (245/40-17) was quicker than both the 255/40-17 and 255/35-18 sizes they tested.

I do believe the 245 had the lightest wheel in the test, so perhaps it was a bit unfair, but it is an interesting result.

 

I found that result interesting as well. Won't change my tire size choice but definitely provides an interesting data point.

Next season I'll be back on 255's, however, I plan on giving the Star Specs a try. While the RS-3's are great in the dry, I don't feel they are the best tire for a "single driver" car over 3 runs. 1st run is a throw away, and if you happen to be in a large heat (or run on a cooler day), all of your runs could end up being throw-aways!

 

Agreed - you can't map the specifics of this test onto an RX-8. Reading the article, I got the impression that both of the 255s were just too much tire for the MX-5. The RX-8 is heavier and more powerful, and I suspect a 245 would get overwhelmed & overheated on a typical course in typical summer conditions.

Although, on a short, super tight course it just might be the better tire. Or maybe at cooler temps, etc.

FWIW, we did an informal test of the 265 Bridgestones vs. some 255 Yoks. The Yoks were practically brand-new and shaved, on light 17s. The 'stones had a good amount of heat cycles & wear on them, although still not optimum tread depth, on my 18" SSRs.

The course was very non-technical and easy to drive consistently. My last two runs on the 'stones in the morning were within .050 of each other, if I recall correctly.

In the afternoon, I could never quite match my times on the 255 Yoks - I was about .2 slower than my morning times on the 'stones. But, that could have easily been driver fatigue (it wasn't the first time I was slightly slower in the afternoon) or maybe I just wasn't pushing the Yoks correctly. But, while the test was imperfect and inconclusive, I'm fairly confident that there isn't a half-second waiting for me if I simply switch to 17s (we were hoping, though - who wouldn't want to find more speed in a cheaper tire?).

The only really obvious difference to me, subjectively speaking, was that I liked the braking better on the 18" 'stones.

 

Seems like the Dunlop's are somewhat the opposite for me. This past weekend out of 6 runs, my first run of a 42.8 +1 was my fastest scratch time. I was running consistant 43.0's the rest of the day.

I'm not sure if the tire's are getting too hot, it was about 90 degrees outside, or if I just have my pressure's off.

I usually start at 36 all around, fronts get to 40-41, rears usually 39. I'll lower it to 39F/37R and keep it there. The car feels better once I do that but the times do not show it...

Discuss!

 

Feel & times are not always the same thing. Stopwatch does not lie!

But, at nats, please keep them at the higher pressures, for sure! j/k.

 

Very interesting result indeed. I agree the test was imperfect (would have been better to test the same tire in the 265 and 255 sizes), however, I'm not surprised to hear that you found braking better with the 265's. I also would expect the 265's to feel crisper in fast transitions as they have the shorter sidewall. I'd expect the 255's to be faster in acceleration zones as they are shorter than the 265's.

Btw, I agree 100% on your thoughts about running a 245 on a RX-8. The larger 255 would definitely provide more heat resistance and the RX-8 already gets a huge gearing advantage from running a 255/40/17 over our stock tire size (~4%).

P.S. Quite frankly, I'm enjoying running my RX-8 in STX so much that I may stick with this car & class for another 2 years.

 

Mike,

One reason the Star Specs do so well in the wet, is that they work well with little to no heat in them. If I was running Star Specs, I'd spray them...often. I haven't driven an RX-8 on them, but I have driven a STS miata, and I also found that they worked best for me, with a small to moderate amount of heat in them. Once they started feeling hot to the touch, performance and times fell off noticeably.

You may get some use out of the following info... While Andy Hollis tested these tires on his ST Civic si, this data could still serve as a useful starting point when deciding what pressures to run. He posted this info on miata.net after the latest GRM tire test:
Link: http://forum.miata.net/vb/showthread.php?t=386891

 

Holy Bananas batman! 39F/37R? Wow, I'm really surprised Mike! I'm running the 255/35 star specs and I'm running 29F/32R and the car feels perfect. Very neutral with a touch oversteer at times, and the tires never give out. I run the tire pressures you mentioned on like...the street. lol.

 

hm. When I go below 35 on the Star Specs. They get really screechy and i can feel them roll over alot. The steering gets very vague. Couple other guys up here run 38-40 as well.

 

Really? Wow. When I chalked it I'm getting zero roll-over at those pressures and if anything the tires feel great. Unless I'm doing something wrong, I dunno.. I mean they feel much better and seem to be pretty good. Anything else you guys recommend I do for testing then since I have a test and tune tomorrow, other than the chalking?

 

When I ran 255 17 star spec I ran at 35/33 and liked how they felt.

 

have you checked your tire pressure gauge recently?

 

+1 Once a season, I always check mine against a Longacre gauge. Mine has always been within 0.5-1 psi.

 

Or camber/toe settings, or spring/bar rates, or weight/balance, or grip/cornering load, or ....

If you're not seeing edge rollover then certainly dont go chasing your tail over some unreferenced number on teh intrawebz furrem ...

 

lol I guess I just wanted to make sure is all. This is only my 3rd year running, most of you guys have been doing this for a long time.. Not to say you guys are old or anything

But yeah I'm not seeing edge roll-over at all. Seems to be pretty spot on with these settings so I dunno. And yes, I check the gauge twice a season and it's pretty spot on with two other gauges I match it against.

 

Pictures from my last event..

 

hey everybody im new on this thread! ive been running cs/bs for about 2 years now and im looking into going with stx next year. ive spent about a week reading all the posts you guys have made and its really informative but i have a few questions. im looking at coilovers but noone seems to push any brand in particular and i havent seen anything about tein. any reason why? once again thanks for your time and answers!

 

^Tein's are just fine...If you don't want to get a trophy at nationals. If your looking to be competitive, you should at least fork out the money for the Bilstein PSS9's.

 

^Agreed Mike. If I had to summarize the coilovers that active STX people who've posted in this thread are using (or were previously using), the brands would be as follows:

• AST
• BC Racing
• Bilstein PSS9's
• Endura Tech
• Fat Cat Bilsteins
• Koni DA's
• KW Variant 3's
• Moton Club Sports
• Stance

I've probably missed a few, but you should get the picture. All of these would do fine on a local/regional level. On the national stage, some are better choicesthan others.

--Chike

P.S. FWIW, some systems like the PSS9's, Fat Cat Bilsteins and AST's are *modular* and you can upgrade your coilovers down the road as money permits (e.g. go from a single adjustable to a dual; add remote reservoirs, etc).

 

^Great driving today Chike. I drove like crap, car was very pushy. Going to make some changes and see how it works out tomorrow.

 

I have a set of Bilsteins for sale that will be better than the teins.

 

uh-oh ........