64 replies to this topic

[luckymiata76]

On the surface it seems like we could save a ton of money on our tire budgets if we went with a 200 TW tire. For those of you that have run 200 TW in other series, what are the pluses and minuses?

 

Question #2-How about limiting us to 1 set of tires per weekend? Stickers for every session at the June Sprints isn't in everybody's budget. 

 

Jeff

#76 SM

[Jim Drago]

I believe Hoosier is working on a tire that lasts more sessions. I believe you are familiar with it. 

I have no experience on the 200 treadware tire. No idea if the first few cycles are still better? if so, probably no advantage. 

 

I think the performance of RR is a good compromise. 

[Martinracing98]

I am guessing a 200 TW rule would allow any tire that meets that criteria. I think any type of open tire is a bad direction. A 200 TW tire may still have a golden heat cycle as Jim indicates above. Some might lower rolling resistance as a result be better for Road America. Others better turn in as a result being better for Blackhawk. As a result we have to bring multiple sets to a track to determine the best tire for that track.

 

When a tire was picked for SRF they worked to get consistent performing long lasting tires. They also looked for tires that communicated well when they are about to lose traction even if they were a little slower. This made the tire better for the average driver not just the top drivers. Trading speed for almost anything else is not going to happen if we have to choose.

[OrangeCrush86]

I don't want to shave tires. Just sayin.

[LarryKing]

I vote for the SCCA going back to Toyo - RR for dry, RA1 for rain.

[Jim Drago]

 

 

When a tire was picked for SRF they worked to get consistent performing long lasting tires. They also looked for tires that communicated well when they are about to lose traction even if they were a little slower. This made the tire better for the average driver not just the top drivers. Trading speed for almost anything else is not going to happen if we have to choose.

You realize that the SRF tire is the same tire we are on now? the Sm7?  I have had several conversations as to the whys and hows.. But SRF is getting 15 plus raceable cycles on these tires and it is not BS..  It is same compound and construction. Different size on one axle and less weight with proper suspension.  "my belief" is that we have no suspension, we are using the tire as suspension, over heating and over working it. 

[davew]

I agree with Jim, we are overworking these tires. many reasons in my opinion; tires are too big and too sticky, wheel offset is too much, we ride the curbs too much, shocks are marginal at best, springs are too strong in order to compensate for the weak shocks.

 

So what can we do?

 

I see only 2 options. The first being a harder, smaller tire. This will save some people money. It will cost others money as a new setup is developed that works with a new tire, testing is expensive. This may also have the added benefit of saving some hubs and other suspension parts.

 

The other option would be a better shock. But this must be done in coordination (maybe not at the same time) as the new tire. It must be tested by multiple people so we don't have any unintended consequences. Price, repeatability, reliability, rebuidability and inspectability must all be part of the equation. And it must be done transparently and phased in over time. Probably a 3-5 year time frame. Known about and publicly tested in year 1, available for use in year 2, required at Majors year 3, required at Regionals in year 4. Non SM classes, such as SSM, SMT SMSE can do what they wish for their local classes.

 

Changing wheel sizes would be a big expense to the entire class. We consume wheels at a smaller rate than we consume shocks. Plus everybody has multiple sets of wheels, but only 1 set of shocks. Stopping people from using every inch of race track is not going to happen. Springs don't really wear out, tires and shocks do. Changing tires and shocks can be put into a consumable expense.

 

I am not on any committy, I know nothing more than what I hear at the track and read in the interwebs.

Just my 2 cents

dave

[gerglmuff2]

I am guessing a 200 TW rule would allow any tire that meets that criteria. I think any type of open tire is a bad direction. A 200 TW tire may still have a golden heat cycle as Jim indicates above. Some might lower rolling resistance as a result be better for Road America. Others better turn in as a result being better for Blackhawk. As a result we have to bring multiple sets to a track to determine the best tire for that track.

 

When a tire was picked for SRF they worked to get consistent performing long lasting tires. They also looked for tires that communicated well when they are about to lose traction even if they were a little slower. This made the tire better for the average driver not just the top drivers. Trading speed for almost anything else is not going to happen if we have to choose.

coming from where the 200tw rule was kinda first popularized (scca autocross), you do not want to go down that path for a stable class system. street tire companies phase in an out tires on a 2-3 year basis, and every year or two there is a giant controversy over what will be the tire to have. and its a big mess, and lots of testing, and alignment issues, and all manner of crap i am so happy to leave behind. it works reasonably well in autocross because the classes change every 2 or 3 years anyway, so everything is always in flux. #productionbasedthings. for spec miata, a nice, consistent, stable rules set, setups, alignments, costs etc etc all pretty well known at least on a basic level. every 2 years reevaluating everything because a new tire comes out would be really, really really crappy. companies also have supply issues from time to time, esp if word gets out that one tire is head and shoulders ahead of another, who wants to play that game? 

the only way to get around this, is to pick a 200tw tire, and just run that.  the upside is removing all the angst and crisis every time a new hot 200tw tire comes out, the downside is it will likely be shit, supply issues remain, and we will be slower. 

id settle for getting 10-12 good heat cycles out of the current tires, if hoosier can do that. id also be up for suspension changes to improve tire wear as well. a new shock would go a long way i think, maybe with slightly revised spring rates (700f, 400r?). id prefer not to trade off speed for wear. these cars are slow enough and i know everyone is like "well yeah, but its a spec class, we only race each other" and maybe that is true for the folks at the top, but the rest of us, bring these cars out to all sorts of track days, open classes, etc etc and would prefer not to be run over by everything all day.

[Bench Racer]

A. PURPOSE AND INTENT
The Spec Miata (SM) class is intended to provide the membership with the opportunity to compete in low
cost, production-based cars with limited modifications, suitable for racing competition.
The rules are intentionally designed to be more open than the Showroom Stock class but more restricted than
the Improved Touring class.

 

Step 1 to removing some equipment failure cost for all the membership racing Spec Miata would be to spec different tires (Ideal, usable cycles until core showed) which would use the same rims we have now. It wouldn't take one year to make the point on equipment failure costs spiraling downward. Back in the day we didn't have all these equipment failure costs (once the upper shock mounting issue was resolved, thanks FatCat/SMAC/CRB). Likely the same people would win, that's not the point of this thread, is it.

[casercrowell]

I'm a fan of 1 set a weekend. Shout out to Preston and Michael Carter for making this work at Roebling Road a few weekends ago. An agreement was made between all drivers that we would run the same tires on Sunday that we had ran on Saturday. This allowed for great racing on Sunday as well as an extra race for me this year. 

 

Not sure how we would make it work as a series? Tire branding? 

[OrangeCrush86]

If the tire is being over worked why doesn't the Toyo suffer the same problems? Not being a smart ass, but it's close to the same size.

[Bench Racer]

If the tire is being over worked why doesn't the Toyo suffer the same problems? Not being a smart ass, but it's basically the exact same size.

 

Check the exact Toyo your talking about, likely construction/sidewalls are different and durometer test it and the Hoosier S7 and the answer will bit you in the a$$. Point being at the get-go Spec Miata didn't have the parts failure issues. 

[FTodaro]

I have also read that the TW rating is not comparable between manufactures. I recall seeing that there is no real objective standard to measure that against, so my point is an open tire with just a TW limit is not workable, plus why would you want open tire, i would suspect less or no contingency with that program.

[davew]

I would not be in favor of an open tire, talk about an arms race. But a more durable tire (higher tread wear rating) would be great.

 

I am not 100% sure, but I think tread wear is a set standard. How a tire is sized (205-50x15) is not a standard. Stack 4 Hoosiers along side 4 Toyo's of the same size and you will see a big difference

[gerglmuff2]

UTQG is kinda subjective. autocross uses it, along with a threat of being put on the exclusion list to keep it fair. as to if it works or not, that depends on who you ask. 

the UTQG is based on a test of tire, they wear a tire and compare its wear to an artifact tire (with supposedly a 100 score). and then they extrapolate that wear. ie, if the tire wears faster than the artifact tire by 2x, its a UTQG of 50, if it wears at half the rate, its a 200 etc etc. as you can imagine this is not a super great test method or rating system. tire companies can also fudge the system. its pretty common knowledge that a lot of the older 180tw tires were not changed at all when they were bumped up to 200tw tires. companies can always advertise there tires as wearing faster than they really wear, but not slower, so they can hedge there bets. we have no idea how close to a "true" 200tw we are basically. 

wear is pretty subjective too. the current two big dogs in the 200tw area are the bridgestone RE71R and the BFG rival-S v2. some say the BFG is faster, esp on concrete, but they are also more expensive than the bridgestones, AND they last about half as long. as stated they are both 200tw. 

its also of note that in the early days of street tires in autocross there wasn't much separation between the time trial and HPDE guys street tires and the street tires for autocross. but now we are seeing separation where the bridgestone is quicker in 3 laps than the hankook RS4, but it also overheats much easier, and gets slower faster. we are seeing the tire needs/wants of autocross and HPDE/time trialers/crapcan racing starting to separate out ... with autocrossers wanting a tire that doesn't need any heat at all to work, to time trialers wanting more heat capacity and wear. so we could find ourselves in a situation where we qualify on one kind of 200tw tire, and race on another (depending on race length). depending on how the rules are written, we are at the whim of the execs of the tire companies. 

street tires is a swear word on roadraceautox.com for a reason ... its a whole mess. it might be marginally cheaper, but the silver bullet or holy grail to save racing its advertised as in some circles, it is not. its messy, any way you go, its just messy.

[Jim Drago]

I have also read that the TW rating is not comparable between manufactures. I recall seeing that there is no real objective standard to measure that against, so my point is an open tire with just a TW limit is not workable, plus why would you want open tire, i would suspect less or no contingency with that program.

this is all just talk as our tire will be Hoosier in SCCA for awhile and Toyo in Nasa for a long time.. 

 

But to play along.. You could NEVER run an open tire with XXX treadware.. Before long, certain XXX treadware tires will be substantially better than others.. 

[OrangeCrush86]

Check the exact Toyo your talking about, likely construction/sidewalls are different and durometer test it and the Hoosier S7 and the answer will bit you in the a$$. Point being at the get-go Spec Miata didn't have the parts failure issues. 

 

 

How much slower is a prime Toyo vs a sticker Hoosier? 2%? 4%?

 

Unfortunately I threw out my last set of Toyos so I can't measure the size difference. If someone can supply measurements I would be very interested how much wide an SM7 is.

[LarryKing]

 

our tire will be Hoosier in SCCA for awhile

 

Why? If the majority SM memberships demands to return to Toyo is the club obliged to do so?

[LarryKing]

 

How much slower is a prime Toyo vs a sticker Hoosier? 2%? 4%?

Same driver at Mid-Ohio pro course. April NASA (Toyo) race best time 1:42.8; July SCCA (Ho-Hos) Mid-Ohio race best time 1:42.5. Yea, I get ambient temps are a factor.

 

Again, if everyone is on the same tire of what possible relevance is "fastest tire?"

[gerglmuff2]

the top crop 200TW tire right now is $144 a tire in 205/50r15 (BFG rival). and it likely wont last longer than the current SM7 under race conditions. 

would it be cheaper? yeah, marginally i think it would. 

worth the PITA and loss of control? mmmmmm, i do not think so.