Which AutoX Tire?

Kumho ECSTA V710 or Hoosier A3S05

 

There's no doubt about it... V710s.

 

agreed

the new Hoosier A6 is coming, but it's not available yet and you'd be best served to wait and see how it performs before making a costly mistake, you can't really go wrong with the Kumho V710 for now

supposedly there are a few other new offerings in the works, only rumors at this time though

 

wider is better if you can control the contact patch and can get them to temp (temp not a problem with V710)

V710 has the advantage of generally being considered marginally faster than the hoosier s05, but also ages more gracefully. i drove a set of V710's over 90 runs, then sold them to a guy that did 6 track days on them and theres still grip and rubber left for him to keep using them this year. they do start to fall off a little after 50 runs in my experience.

hoosiers are lighter, and that might make a significant difference on a light car.

james

 

Keep in mind a big fat wide tire on a small wheel does not give you a big patch. When you pinch the tire on a wheel that is to small you will make the face of the tire round rather than flat. Also when you bend the sidewall in you change the spring rate that is built in the tire. A wider tire is most times also taller so you will lose gearing.

 

and as usual lighter is no indication of actual inertia and inertia is no indicator of overall tire performance

 

Tire construction also greatly impacts contact patch. 275 Hooisiers had a full inch on the current 245 710s even though they weren't as good. Hoosiers utilize a cantilevered construction that helps keep them flat. In constrast, the Kumho 265 V700 Ecstas had no more contact patch than the stock 225s. That in conjuction with the gearing disadvantage Jason mentioned makes me skeptical that a 265 V710 will be faster on an RX8, but who knows until you try them. The one area where the bigger tire would help would be to avoid third gear shifts on faster courses, but something tells me that after Ft. Myers we won't be seeing much of that for a while, legitimate protest or not.

 

I don't think a 265 Kumho V710 exists in this market. Not to mention the 245s are a tough fit on an 8 inch rim, I can't imagine a 265 on that same rim.

 

Correct, but people have been speculating that the 265 will be one of the new sizes available this year. If a 265 V700 fits, don't see why the same size in V710 wouldn't. True the 245 V710 is a little difficult to get on, but leave them out in the sun for a while, they soften up and get much easier. We've only had to resort to the ether trick on one of them.

 

I posted this in the gulf forum to the same question... so i guess i'll post it here. Interested what yall have to say...

Personally i recommend staying off slicks. Slick tread tires can cover alot of your mistakes and still give you a fast time. You'll have good times, but you won't be able to improve as a driver as efficiently.
I ran with turbo last season on the world's crappiest 225 tires. By the end i was getting a good hang of it, and putting up competitive times... i think it was a good learning experience.
This Season i'll be running on Falken RT-615s with a 255 tire on a wider rim. Still not slicks, and still not even 275 wide... and in return a better tire from before while still being very challenging.

just my .02

So does anyone else here think it might be better for The_Mighty_Red to stay off of slicks for now?

-hS

 

265a does not equal 265b.

Stack a set of 265 V700s unmounted up next to a stack of 245 V710s, the 245 stack is taller than the 265s. How can that be you say, well part of it is sidewall, but also all the V710s tires are a little oversized.

 

We'll then I feel sorry for the 350z owners out there.

 

You are correct it can cover some stuff up. However R tires can also make so so cars very fast. To me the time to get on race tires is as soon as you can afford an extra set of wheels and tires.
Sure in the end YOU have to learn to drive, but it sure is more fun to have a fully setup car to learn in. Kind of sucks to waste a lot of time trying to fix problems that might have something to do with the car and not just the driver.

 

What class are you going to run?

Most of us are B Stock guys and am sure that is why we are telling you to get the 245 V710. If you are not in stock, BSP or SM, get some 18X9-10" with some 285 V710s.

 

Thats true, i wouldn't try learning on a POS mid 90s cavalier... but in my opnion, the RX-8 comes from the factory good enough to learn from. Upgrading to a decent set of 245's on the stock wheels, with some basic suspension upgrades makes sense, but i wouldn't go as far as getting slicks.

Then again.. its really up to the owner to decide what his goals are, and what he feels is the best way to get there.

-hS

 

From my experience the learning curve is about the same. Good equipment and there is less incentive to improve. Stay on the OEM tires and you're so far behind that you can't really tell how we'll you're doing anyway. If you have the $, go to the R comps, you'll have a lot more fun while learning.

 

Lets ASSume we are talking about an RX8 here. I agree the RX8 is good out of the box with the exception of the POS tires. A stock RX8 with a race alignment and set of good 245s, Advans, Ecsta MX, Falken, KDs etc would be a great start. However imho nothing beats the R tires, makes the car come to life.

 

Another vote for R-tires. Assuming you're hooked and planning to eventually run R-tires, get them as soon as you can afford them. Get the right equipment and you know that any deficiencies are driver-related. Stick with subpar tires and you'll rationalize the gap from the winners away. And this bit about covering up mistakes...some things are mistakes on street tires, but not on R tires...so you might have trouble going back to street tires, but if your ultimate goal is to compete on R's, mount them up ASAP.

 

Thank you all very much for your inputs and advice. I have taken it all into consideration and here are my thoughts.

I am hooked. I had such a great time I can see myself doing this for a long time. I want the R-tires.

I do agree, to a point, that learning on non-performance parts is a good way to sharpen your basic handeling skills. However, last Sunday's event showed me just how important good tires are in getting the full performance out of the car. Because of the tight turns, with my street tires, I wasn't even able to use all the power the car had to offer. I had to "lay back" on the throttle the whole run because the car didn't want to stay "on the line". Every time I tried to push it through the exit or in a slalom, it went wide.

I will attribute part of the lackluster performance to my driving skills (each run was progressively better) but I can only go so fast before I end up turning circles. That much I will contribute to the lack of traction.

After my second run, I rode with a E-stock (MR-2) running V710s and it was a completely different experience. The G-Forces were much stronger. I knew then what I was missing - grip.

Here is my dilemma, I've already made intake and suspension mods that move me out of Stock (and I don't feel like undoing them right now). That would put me into STU - if I ran 225 tires. However, I'm currently running 245 street tires and the smallest 18" Kumho V710 is a 245 anyway so either way I'm in BSP - I'm stuck (unless I use a different brand of tire).

So, since I'm already in deep water, I might as well get 10" wheels and run 285/30 Kumho V710s all around (the V710's next step up from the 245s). That should give me all the grip I need.

Reference: list of available Kumho V710 tire sizes
http://www.kumhousa.com/Products/Ptn...=1&PtnID=EV710

 

So at this point you are looking at STU or BSP, btw STU allows up to 275 tires on the RX8. So you can buy the wheels you need for either class, something in a nice 18X9-10" will do just fine. Then if you want to run STU the 265 Advan is the hot tire with the 275 Falken 2nd best but less money. If you want to run BSP the 285 V710 is the best choice both for performace and value.

 

Actually, you can run up to 275's in STU (on any wheel)...but you can't run V710's...you need street tires (treadwear 140+)...there are some really good ones, but V710's are still a whole new level.

Yes, your other choice (without undoing mods) would be to go BSP and go wheel/tire crazy.

 

I did not know I could run up to 275 in STU. I read the SCCA book and understood that 225 was the maximum for Street Touring as stated on page 69 of the 2006 SCCA Rule book. I'm still not sure where in the book that was stated. Can you reference me to a page number? Thanks for clarifying that.

If that is the case, I should go to STU. There are some very fast cars in the BSP class.

Thanks!

 

It is not a natl class so it does not have to be in the book.

http://www.scca.com/_FileLibrary/Fil...talclasses.pdf

 

Thanks for the direction. I have some serious thinking to do... decisions, decisions..

Thanks everyone! You've been a big help.

I'll let you know what I figure out.

 

As i was reading this... this was just screaming "Throttle Control", and this is my example of a skill that could be sharpened on your current tires, or covered by slicks... but i'm gonna let this one go for now.I was thinking the same thing. I was always under the impression that slicks would take you out of STU. You could also go completely crazy and join me in SM
I don't think 18X10 will fit on all 4 wheels. I was under the impression that 18X9.5 with the Enkei RP01 (?) was the widest we could go up front.

You said you changed the suspension. How much lower is the car now, and which springs did you go with? This could also effect how wide of a wheel you can go with.

Oh also... glad to hear how much your enjoying autocrossing. Theres a good PCA event coming up this sunday that I highly recommend you check out. It'll be lots of fun. I'll send you a PM on the info.

-hS