Anyone in CS or AS using Hoosier 255s?

[rgodby]

Hi All - It's been a while since I saw any conversation on these. Anyone adopted these tires yet? Early indications in the spring from mainly the RX-8 community suggested serious cupping could occur without higher inflation. Since then I have seen or heard little. Has anyone noticed at national events they have been at what people are using? Nat events out here have been sadly lacking in Solstice participation. How about other events? I did read that Hoosier was looking into posssible issues early on but never heard if any tire manufacturing changes were made. Anyone know anything? Grassroots Motorsport has a test on the 255s vs 285s on an 18x8 wheel on an RX-8 this month. Unfortunately they included no tire inflation info but did find the 255s could be faster. From that I take this article to mean they could be at least competitive. Any one have any experience on the Solstice? I am particularly interested in CS results as it is almost time to make another dreaded race tire order...

-rob godby
Laramie, WY
2007 Solstice NA (Zok)

[AlanBDahl]

On the GXP the 295 is the tire to get hands down. They are a lot easier to mount than the 285s, stick like glue and wear nicely. Haven't seen either of our local NA drivers try the 255s yet so I can't give you any data on them, sorry.

[snaponbob]

At the 2007 and 2008 Solo Nationals I did not see ONE set of 255 A6s on ANY Solstice. Alan is correct about 295s being the correct tire for the GXP, but most of the 2.4 Sols had 285 A6s. There is a guy on sccaforums.com trying to sell a new set for under list so you may want to take a look at that. Crank in some negative camber and you are set for Solo.

[acrace]

FWIW - Rogers/Harvey on their RX-8 ran the 285s at the Peru N.T. They're the ones who did the test in GRM.

snaponbob - the reason you didn't see any 255s at the '07 or '08 Nationals is that the size was just released for this season. But I agree, using the 295s for the GXP and the 285s for the NA cars is the safe decision when it comes to buying tires.

[MTA]

AlanBDahl: What sizes are the 2 NA's in your area are running?

What am I missing in the differences between the 285's and 295's? Is there a different construction? Per Hoosier data the 285 is: .4 shorter, .1 wider, min. rim width asks for .5 more, and both the 285 and 295 weigh 24 lbs. and both cost $320. On paper it would seem that the 295 is the best choice.

rgodby: If you are looking at the new 255's then the taller (.7) and same width 275 would be a tire to consider the expense of being 1 lb. heavier.

How long has the 275 been around and how come there isn't more interest in the tallest A6 available in Solstice sizes? Granted the 255's and 275 are .6 narrower than the 285 but at 10.3 wide you have a pretty good footprint and save weight on each corner.

[rgodby]

Thanks for the thoughts guys. I have trolled through the forums here and elsewhere and there just isn't a lot on anybody using the 255s on the Solstice I could find. The reason I posed the question is that I actually have a nice new set of 285s ready to go but wondered if for my second wheelset I might try the 255s instead of getting my usual 285s since the tires on those wheels are kaput. Having a set of both sizes I could see as an option depending on the course. It seems to me that the 255 could have advantages in places and the 285 elsewhere might be advantageous depending on the course. Of course, I would have to keep my driving consistent enough to really see a difference...

Hopefully that answers the question about why I didn't look at 275s. I thought the 255s could be different enough to create a tire option instead of having two sets of the same wheel/tire.

I may still try the experiment since it seems there is no info out there.

[snaponbob]

Originally Posted by rgodby Thanks for the thoughts guys. I have trolled through the forums here and elsewhere and there just isn't a lot on anybody using the 255s on the Solstice I could find. The reason I posed the question is that I actually have a nice new set of 285s ready to go but wondered if for my second wheelset I might try the 255s instead of getting my usual 285s since the tires on those wheels are kaput. Having a set of both sizes I could see as an option depending on the course. It seems to me that the 255 could have advantages in places and the 285 elsewhere might be advantageous depending on the course. Of course, I would have to keep my driving consistent enough to really see a difference... Hopefully that answers the question about why I didn't look at 275s. I thought the 255s could be different enough to create a tire option instead of having two sets of the same wheel/tire. I may still try the experiment since it seems there is no info out there.

There is probably "no info out there" because people, over the past few years, have done the math and gone for effective WIDTH. The taller 255 will present a negative result with acceleration while being ONE INCH narrower than the 285. Having just switched to 315s from 295s rest assured that extra tire patch absolutely makes a BIG difference.

[rgodby]

I see where you are going Snaponbob and I really do appreciate your experience. If it were only that easy to select a tire for a stock class car though. Rim width is limited to the stock 8". The Hoosier 255 was made from an existing tire by taking the carcass and widening it, so the stated aspect ratio is too high - it is really more like a 28 or 30, certainly not a 35. Hoosier indicates from their stated measures that the 255 is only .7 inches less in width, but of course the 285 is very rounded on the 8" rim while a 255 is less so. The 255 is lighter. Bottom line, the tire is a tiny bit shorter and effectively should be about the same width, and could be lighter. Theoretically then there is a possible benefit. In the offseason there was a lot of speculation about this, particularly on the RX-8 and SCCA forums, but after the early cupping problems on the outer edge (that look like they were caused by underinflation issues according to the RX-8 guys and Hoosier), people seem to have abandoned the testing or comitted to other tire sizes for this season. Further, Solstice drivers may need to look outside the box for some performance advantages in CS (and next year when combined with BS) given the 2007 Miata MSR has been shown to be as fast or faster.

The point of the GRM tire test is that there are tradeoffs and the prevailing wisdom that wider is always better may not always true, especially if you are constrained in other dimensions like rim width. I have no doubt that on your car wider is better as you can widen the wheel width as well under class rules. The way I see it though (and the reason Hoosier says they made the tire size in the press release when they offered the tire) is that the Solstice and the RX-8 might benefit from a tire like it. Another interesting setup would be a stagger too I suppose (285r/255f). I figured I would ask if anyone had either experienced the tires or had seen others that were using them.

I really do appreciate everyone's comments.

-rob
'07 Zok NA

[snaponbob]

Originally Posted by rgodby I see where you are going Snaponbob and I really do appreciate your experience. If it were only that easy to select a tire for a stock class car though. Rim width is limited to the stock 8". The Hoosier 255 was made from an existing tire by taking the carcass and widening it, so the stated aspect ratio is too high - it is really more like a 28 or 30, certainly not a 35. Hoosier indicates from their stated measures that the 255 is only .7 inches less in width, but of course the 285 is very rounded on the 8" rim while a 255 is less so. The 255 is lighter. Bottom line, the tire is a tiny bit shorter and effectively should be about the same width, and could be lighter. Theoretically then there is a possible benefit. In the offseason there was a lot of speculation about this, particularly on the RX-8 and SCCA forums, but after the early cupping problems on the outer edge (that look like they were caused by underinflation issues according to the RX-8 guys and Hoosier), people seem to have abandoned the testing or comitted to other tire sizes for this season. Further, Solstice drivers may need to look outside the box for some performance advantages in CS (and next year when combined with BS) given the 2007 Miata MSR has been shown to be as fast or faster. The point of the GRM tire test is that there are tradeoffs and the prevailing wisdom that wider is always better may not always true, especially if you are constrained in other dimensions like rim width. I have no doubt that on your car wider is better as you can widen the wheel width as well under class rules. The way I see it though (and the reason Hoosier says they made the tire size in the press release when they offered the tire) is that the Solstice and the RX-8 might benefit from a tire like it. Another interesting setup would be a stagger too I suppose (285r/255f). I figured I would ask if anyone had either experienced the tires or had seen others that were using them. I really do appreciate everyone's comments. -rob '07 Zok NA

The GMR test was flawed on a LOT of levels. For starters, the Hoosier they used was an outdated version. Secondly, the RX8 is a tough car to select tires for as it really does lean a LOT. Hoosiers NEED more negative camber to work than other tires.

You are partially correct about the "proper" rim width for a given tire size. If you were to select ANY radial r-comp except a Hoosier, than you should go with the chart. If you were to use a non-Hoosier the very best choice will be the Kumho V710. It is the only other r-comp having, but it simply does not have the grip of the Hoosier, but lasts a lot longer. At the Solo Nationals almost ALL of the C/Stock Sols were on Hoosiers, and ALL were running 275s or 285s. They ABSOLUTELY will mount up properly. ALL of the A/Stock Sols and my Sky have been on 295 Hoosier A6s. The 275, 285, and 295s will mount properly on an 18X8 on our cars. Call Hoosier and ask them!! I have now moved the B/SP and have 315s on 18X9. While 18X11's would be best, I simply could not afford $3000 for custom wheels so went with the 9" OZs.

It's your money, so I do not have a vested interest in your tire choice. But YOU do. If you buy 255 A6s you will be giving up a tremendous amount of grip and you will loose a second or more on a 45-60 second course. Do yourself a favor and get the 285s. The 295s are just too big for the 2.4s which can mean they will not warm up evenly, and THAT is BAD for traction. Then put about 2.25-2.5 negative camber in the front and 1.5-1.8 negative camber in the back. The car will stick better than you can imagine.

[rgodby]

Hi Snaponbob - agreed - the GRM test was flawed in that they did not give additional info necessary to judge the outcome. I'm not a noob here - I have used 285s for the past season mounted on SSRs using proper alignment settings so I am aware they will fit and how they work. I also agree with your other comments regarding Kumhos and Hoosiers, that the RX-8 is not a Solstice and that from my experience 295s do not work as well as 285s on a CS car (2.4 Solstice).

I really do appreciate your advice. The question is does anyone have any actual 255 data here, either observed or experienced on a Solstice? We could armchair this all day. I can imagine a lot of set-ups here that could be improvements. The problem is that to optimize the 255 on a Solstice will require testing and trial and error. I can also imagine that after trying everything the 285 is the faster set-up to use. But maybe not.

We all know what a CS Solstice does on 285s. I already have a set of mounted new 285s so the reason I am willing to even consider an experiment is that I have a worn out set of 285s on another set of SSR wheels that need to be replaced. I don't get any faster from where I am now if I buy another set of 285s (and no worse). I assume 255s are likely not to be much slower than 275s as the tire is the same width as the 275, only slightly shorter according to Hoosier
https://www.hoosiertire.com/rrtire.htm). The question is, has anyone seen a 255 set-up? What is the potential? Is there any?

I do appreciate you trying to help me. You obviously have a lot of experience. From what I have read here though, no one has actually tried anything new like this and until they do or someone shares some experience I guess we have to agree that it is still an open question.

-rob

[poSSum]

Originally Posted by rgodby The question is, has anyone seen a 255 set-up? What is the potential? Is there any?

You're not the only one asking the question and I do believe it to be valid.

As a mid-packer, I've learned to follow, not lead, that way I can measure my driver development against the proven front runners.

My co-driver and I went to '08 Nationals on what was essentially the '06 CS winning setup: Kumho 245's, stock shocks and bars. My co-driver just barely grabbed the last trophy.

In March we ran the Houston Tour using the current thinking: 285 Hoosiers, Koni SA's, base model front sway bar. My co-driver won CS and beat the 2nd place driver and car from Nationals to do it. Lesson learned.

[snaponbob]

Originally Posted by poSSum You're not the only one asking the question and I do believe it to be valid. As a mid-packer, I've learned to follow, not lead, that way I can measure my driver development against the proven front runners. My co-driver and I went to '08 Nationals on what was essentially the '06 CS winning setup: Kumho 245's, stock shocks and bars. My co-driver just barely grabbed the last trophy. In March we ran the Houston Tour using the current thinking: 285 Hoosiers, Koni SA's, base model front sway bar. My co-driver won CS and beat the 2nd place driver and car from Nationals to do it. Lesson learned.

And THAT is THE hot set up for a Sol in C/S. It is jaw dropping to watch a properly set up and well driven C/S Sol 2.4 GXP. SOOO flat through slaloms.

[rgodby]

And that is the set-up I am running now. Of course, the biggest improvement I can likely make is my driving...

After that though, I am always looking for that "unfair advantage" as Mark Donahue called it.

I think I'll take the plunge and try them. I will forward anything learned to the group, but given the date there likely won't be much until near to Nats. I am the only one entered in CS at Eagle. I stunk the place out in Farmington. Bad time to completely forget how to drive. Up to that point it had been a decent season in a competitive region though no one runs CS. I usually gauge my results relative to BS and AS results. Since then I have been running completely worn out tires (which I also used in Farmington, not that I am making up excuses but I only heat-cycled the new tires there and put them away for later in the season given the thin field).

Again, thanks for all the help everyone. If anyone does hear something please share...

[poSSum]

Originally Posted by snaponbob And THAT is THE hot set up for a Sol in C/S. It is jaw dropping to watch a properly set up and well driven C/S Sol 2.4 GXP. SOOO flat through slaloms.

I suspect you meant ZOK.

[snaponbob]

Originally Posted by poSSum I suspect you meant ZOK.

OOPS. My bad. I had just finished destroying a try (I love my chain saw) and was all hot and sweaty so I was not thinking straight.