Topic: Kumo 710 or Hosier A6, or R6

[numbbers]

What are the pros/cons for both Autocross and track days? Also, what are the best sizes for stock wheels, and what are the max sizes with a new wheel/tire combination? I.E. If you were just going for max performance, regardless of class, what would you run, for stock ride heights?

I am planning on doing some autocrossing, and maybe some track days with the Mallett, and I would like opinions on the best tire/wheel combos.

[snaponbob]

R6s are fine for track days, but worthless for Solo.
V710s are not quite as good as A6s for Solo but live almost twice as long.
A6s are okay for FASTEST laps at track days but will be short lived.
V710s will fall in between A6s and R6s at tracks.

If you want one set for both, V710s should work.

[boardkat]

cliff's notes: for dual purpose (track/autox), as bob mentioned, get V710's, with the recommended width wheels for the size you desire.  for ultimate grip, longevity be damned, both on the track or for autox, get A6's.

as an addendum to what bob had to say... make sure you get the recommended width wheels for the tire size if you want to fit V710's.  they DO NOT like to be stretched, whereas you can get away with skinnier wheels and fit much bigger hoosiers.  case in point: for autox purposes (would NOT try this on the track), you can squeeze 295/30R18 A6's onto stock-sized wheels (18x8)... pinched, but possible, and actually not that difficult to mount (but obviously reduced contact patch).  V710's, you better be paying your tire guy an arm and a leg to get him to mount a similar size (285/30R18 - i've seen it done by a local tire guy, but it takes him about 1/2 hour a tire and he charges $50/tire), and even the 245/40R18 are more difficult than you'd think to fit on stock wheels and will frustrate your average tire chain mounter.  moral of the story, unless you're running a class that limits your wheel size (you said mallett, right?  guess not!), no sense pinching any tire, even if you can.  

also, tire wear is a surface/driver-dependent variable, and while i don't quite agree with double the life from V710's over A6's for autox (in my experience on multiple FWD/RWD/AWD cars i've owned with both tires - the track, without a doubt, the A6's won't last nearly as long as a V710), the V710's definitely fall off much more slowly, and are better at end of life than an end of life A6.  as bob mentioned, you're ALWAYS giving something up, grip-wise, to a fresh A6 though, whether it be on the track or for autox.  that said, for dual purpose (track/autox), it's a no-brainer, the V710 is the tire for your needs - with the RIGHT wheel width

as for the R6, great track tire, very limited use in autox.  i HAVE seen a very small subset of competition getting A6-equivalent grip, but it takes two drivers at a prosolo on asphalt on a 90deg+ day before the *2nd* driver gets that kind of grip after his/her first two runs.  for regular autox, they're useful on lightly attended practice days when it's hot out and you're getting very little time between runs.  on a typical autox competition day, forget it, they're barely better than a street tire, and nowhere near as forgiving when there's no heat in them.

caveat: i've spoken with the lead R&D guy @ hoosier recently.  they are reformulating their compound and will have a higher-grip, longer lasting A7 tire out in the next 12 months.  that will change the game, especially in terms of longevity.  we'll see if/when it comes to pass.

cheap tip: john berget is a dude that gets takeoffs from guys @ road america in wisconsin.  give him a call (his website is abysmal but he's very helpful on the phone and will do everything to help you out) if you want to dip your feet in the water relatively cheaply.  new rcomps are NOT cheap!!

[numbbers]

Thanks guys, just what I was looking for.

So, I am thinking about 245/35 for the stock wheels, and maybe going to a wider wheel later, if I think it is necessary.  Does this sound about right?

[shabby]

I can't imagine autocrossing a v8 kappa with 245 tires, even a gxp can light up 295 hoosiers with ease.

[boardkat]

if i'm you, like shabby said, go as wide as you can with the kind of gearing (t56?)/power (ls2?) you have.  18x10 or 18x10.5 w/ 295/30R18 A6's / 285/30R18 V710's.... or 315/30R18 A6's / 305/30R18 V710's on 18x11's.  that'd be what i'd be looking at.  245's will be a waste of money!  if you're looking for a cheaper route, you can always find inexpensive 18x9's in our bolt pattern - call up john berget, get a set of 275/35R18 A6's takeoffs and enjoy!  you can even get away with that size on the stock wheels, without too much pinching or worry if you want to do a track day on them (though they're much happier on 18x9 / 18x10).  i wouldn't go any smaller than that.

[snaponbob]

Hoosier A6s in 295 size will easy mount up on 18x8. Just look at all the GXPs (and a certain Redline) that run/ran at Solo Nats in A (now B) Stock. Can't recall where the inexpensive wide wheels came from (mentioned earlier somewhere on this forum), 18x11 or 12 with 315s will work well. And one can choose V710s or A6s. You'll need them with a V8. 

[Graywolf]

I have a full set of A6 and r6 mounted on 18x8 oz ultraleggra 295 30. To be most competitive buy the a6 295 30. Wheel width as the guys stated is important but first check out the rules for your sanctioning body. It may throw you into a higher class which may not be worth it. Yes the a6 will wear a little quicker but winning is everthing or save money and don't race which is by far the most money saving choice.

[boardkat]

Hoosier A6s in 295 size will easy mount up on 18x8. Just look at all the GXPs (and a certain Redline) that run/ran at Solo Nats in A (now B) Stock. Can't recall where the inexpensive wide wheels came from (mentioned earlier somewhere on this forum), 18x11 or 12 with 315s will work well. And one can choose V710s or A6s. You'll need them with a V8. 

remember, he mentioned possible track days.  there's NO WAY in hell i'd be running my 295's on 18x8's for anything but autox.  just because you can doesn't mean you should, especially when you're hucking your car around at triple digit speeds!
all this said, it's coming from a dedicated autox'er.  don't the SSB guys max-out with 275's on their 18x8's?  but that's with 1/3 the horsepower of a mallett, and hundreds of pounds lighter i'd imagine.  food for thought.

[Vanguard]

I don't have as much experience out there as SOB and the others on this forum, but I'd like to add my two cents to a couple of things mentioned...

I got a used set of 305 (maybe 315...tires aren't here ATM) and they mounted just fine to an 8.5" wheel.  However, I have them mounted reverse because of fairly large gash in one of the shoulders.  I've had them since last summer and done almost a year's worth of events on them and they are just now starting to show a few cords. 

And about John Berget...I had an issue where I asked for A6s and they sent me R6s instead.  After calling him, he said that I had to pay shipping for sending back AND the new shipment.  On top of that, they were 275s instead of 295s as I asked for.  And to top it all off, I started getting cords after one event...the Socal regional at El Toro.  I was running them with as much camber as I could get in (right at -3, I think) and at about 40psi. 

Moral of the story: Buyer beware when it comes to used R-comps...

[snaponbob]

I pinched 315s on 18x9's, and the results were "okay". Doing that on 8.5's is a bit much.

[numbbers]

Well guys, the first set are going on the stock wheels.  Depending on the results, and the fun factor, I may go with wider wheels and wider tires.  So, I am back to what should I buy for the stock wheels?

[snaponbob]

What are you going to do the most of - Solo or track? Best compromise for both will be 245 or 255 V71)s, NO wider. A6s or R6s you CAN run 295s, but As will be killed on long track runs and R6s will not hook up well at Solo events.

[Uranium-238]

Don't A6's get really slick once they heat up?

[snaponbob]

Don't A6's get really slick once they heat up?

The answer is sort of "qualified". At SCCA annual Road Dace Run Offs, the Phoenix Racing SSB and T2 Sols have used A6s for the qualifying and races. They have to be careful in order to get the full 18-20 laps, but at the end the tires are completely used up. But, they are quicker than the  R6s. In Solo, A6s simply are the tire to have as it is hands down the best to have (in non-wet conditions) at the cost of shorter life cycle.

The OP's question seems to be "what tire can be the best PACKAGE for road AND Solo", and it would have to be the V710.

[Graywolf]

If your running track days most places require a roll bar and 6 point harness /arm strapes. If your not equiped with these options then your probably can only compete in autocross. A6 is the choice. You can run track days with street tires and still have a blast.

[numbbers]

What are you going to do the most of - Solo or track? Best compromise for both will be 245 or 255 V71)s, NO wider. A6s or R6s you CAN run 295s, but As will be killed on long track runs and R6s will not hook up well at Solo events.

Thanks Bob.  I am not finding a 255 on Kumho website, they jump from 245 to 315. 

[snaponbob]

Actually, they jump to 285's. http://www.tirerack.com/tires/tires.jsp?tireMake=Kumho&tireModel=Ecsta+V710

Bottom line, with 18x8's you are stuck with 245's. At the risk of sounding snarky, if you could manage the money for a V8 Kappa, where is the problem with buying wide wheels?!?!?

[Critterman]

after you buy the V8 Kappa, there may not be any left for wider wheels

[numbbers]

Actually, they jump to 285's. http://www.tirerack.com/tires/tires.jsp?tireMake=Kumho&tireModel=Ecsta+V710

Bottom line, with 18x8's you are stuck with 245's. At the risk of sounding snarky, if you could manage the money for a V8 Kappa, where is the problem with buying wide wheels?!?!?

Nothing wrong with buying wider wheels.  But, I have the stock wheels, and I just want to see if I enjoy autocrossing and track days as much as I did when I was younger, before I invest in more wheels and tires.

[Critterman]

Truth is you will enjoy it more if you have control and that means bigger and stickier rubber.