Autocross tires

[badrich]

I currently am running Halibrand 15" 6-pin knockoff wheels (7 1/2", 9 1/2") and BF Goodrich T/As. Adequate street tire only. I used to autocross an old Stingray and used to drive it to the event. I would like to do the same with my Cobra. I love the appearance of my 15" wheels but there don't appear to be any DOT tires available that would be suitable for serious autocrossing. My car is a fair weather beast, so dry performance is all I am interested in. I have a friend who uses the Kumho Ecsta V700 on his Cobra and loves them. He uses 275/40ZR17s (10" tread). I'd like to use that size up front, but I'd like something larger on the rear. The challenge is that their next size larger tire is 335/35ZR17 (12.4" tread). While I'd love to go that large, I'm worried about tire clearance. Has anyone out there had success stuffing these large tires under a Contemporary or similar beast? A *little* rubbing would be OK. Or is there another brand that would stick as well but be a tad smaller? I am planning on going with PS Engineering wheels. I'm still breaking in my new motor, but it will be ready as soon as the weather clears, and I am anxious to really learn how to drive this beast properly. And for me, that will be autocrossing. Thanks for your help, Rich.

[Cal Metal]

No idea on the size issue. Kumho tires are very good AutoX tires and do very well in rain or wet surfaces--not so well on cold surfaces. The preferred tires for AutoX are the Hoosiers. They are more expensive than the Kumhos and their life is considerably shorter, but the adhesion is very good.

[thorconstr]

I have 275/40/ZR17 fronts & 335/35/ZR17 backs on PS 9" w/ 3" backset fronts & 11" w/ 4" backset fronts. The tires are Michelin Pilot Sport. My car is a Kirkham 427. I'm sure Phil at PS has made rims for a Contemporary and can set you up with the proper backset, should be the same as far as I know. I got my tires from the Tire Rack (www.tirerack.com) $287.00 ea. fronts & $337.00 ea. backs. The road hazard was a few bucks more, no tax! I called the order in so I could talk to someone with some knowledge about tires. All the tire places I talked to said these are the best. A bit more expensive, but a very small percentage of the overall car price. And being the only thing between the car and the ground, I didn't want to be dollar foolish at speed with my butt! Good luck!

[Jamo]

Hoosier TDs on 15" work wonderfully.

[Cal Metal]

Jamo is correct. The Hoosiers are outstanding tires for AutoX

[badrich]

Doesn't look like there are many autocrossers out there. Most of my club members are open track enthusiasts, but you won't see me going 160 MPH at Thunderhill until I have thoroughly wrung out my beast at slower speeds. When it is sorted out and I feel like I really know what I'm doing, I'll consider open track. Until then it is autocross time.

Thanks guys for the feedback. Al, I am sure the Michelin Pilot Sports are great high performance street tires, but have you autocrossed on them? I do plan on talking wheels and tires with Phil (Schmidt?) at PS Engineering. This stuff is probably old hat to him. And you are right, now isn't the time to worry about price. I stopped worrying about that a long time ago. I'll pay whatever it takes for the best tire for my needs.

Jamo and Cal Metal: I know many people have had success with Hoosiers, especially with racing. I've also heard that they can be a little twitchy when they are cold, which can be exciting on the street. Their 15" sizes appear to be a little limited, at least with the Sports Car D.O.T. A3S03, which goes up to 10.1" wide. Their P315/35ZR-17 has a 11.7" tread, which is closer to my desires. I also notice that they have this interesting message that says that their D.O.T. racing tires are "NOT INTENDED FOR HIGHWAY PURPOSES." I need to talk to them and see what that's all about. Also, one can purchase Kumhos already heat cycled, which is a big sales point to me. Again, I do appreciate all your input. Decisions, decisions! Rich

[era427tp]

I'd go with the Hoosiers,no way I'd put some korean off brand tire on my car.

[badrich]

Actually, no matter what street/autocross tires I end up with, I plan on replacing the BF Goodrich T/As that are on my Halibrand rims with a set of Goodyear Stock Car Special slicks, the kind with fairly soft compound and those big white GOODYEAR letters on 'em. They came with the car and I plan on sneaking off to a local autocross when there's no chance of rain and see how they perform. They may need to get pretty warm before they stick properly. And this is what my machine will wear when I enter my first car show. I hope that will make up for my running Kumhos, if they appear to be my best choice for autocrossing. Rich

[Jamo]

Ok Rich, time for you to be a bit more specific of your intended uses.

If you're talking about using autocross tires just for autocrossing, then the Hoosiers will do as well if not better than the Kumhos, regardless of them being 15" versus 17". You commented about them being a little "exciting" on the street. Are you going to run them on the street? Because your last post now mentions using big letters on the street. If you're not going to running the Hoosiers on the street, why do you care if they hunt? If you're properly set up for autocross, you're going to have so much toe-out that the tires will be the least of your worries for "hunting". Tire Rack will shave and heat cycle them for you. I normally get mine shaved, but cylce them in by driving them to the track. I've tried all manner of autocross tires over the past 20 years...on everything from a 92 Vette, to heavy Audis to Cobras. Yokohamas are not called Rockahamas for nothing, but will wear through two seasons if you want, Goodriches are excellent but expensive and would rarely take me through a season, Kumhos are damn good...but one brand remains constant in providing damn good stick through its life, reasonable wear and reasonable cost, not to mention 15" sizes to fit a Cobra...Hoosier. For it's limited use in autocrossing, 245s up front, and 275s behind do quite well.

I ran TDs on my Butler as a single tire for autocross and street duty for three years. I would set the toe back at the event's end and drive back the 60 miles to home. Yes, they hunted and picked up gravel...BFD. Just keep both hands on the wheel.

I run big letters on the Kirkham. They are not going to be legal for any street class (ie., street prepared) at an SCCA autocross...non-DOT. Also, they're not going to warm up fast enough, nor do they have as stiff a sidewall as one would like for autocross. For that, the TDs are better, and they are legal for classes typically run.

I gave my advice based on you running tires specifically for the autocross. TDs can be used on the street, but there are compromises to make.

[Excaliber]

I liked the AO32R Yokohamas myself. A DOT approved auto X tire that gave "decent" highway mileage and excellent track traction for the price. I would try the Kumo's if I was doing in "next time" just to compare. I found the price and mileage from the Hoosiers was just to "over the top" for a weekend racer and a daily driver application.

T/A's?? Man, what a joke THOSE tires were!

Ernie

[Jamo]

Oinie

If I was autocrossing on lava flows, I'd use Yokohamas too!

[rdorman]

The TDs cut four seconds + off my autocross times and dropped 16 pound of unsprung weight on EACH corner. 245/275-60 is plenty of tire. Car fealt as though it had been granted new life once the TDs where mounted.
Rick

[badrich]

Gentlemen: Thanks for the feedback. Lots of positive comments re: Hoosiers. Ernie, thanks for your Yokahama comments. Sounds like a good, all-around high performance tire, but tire mileage is less important to me right now than performance. Besides, I am avoiding lava courses. ; ) Good luck on SB 2021. We're lucky here in California.
Jamo: Sorry if I confused the issue by mentioning my Goodyear slicks. I live only a couple of miles from an company that occasionally holds autocrosses on one of its large parking lots. I figured I could sneak over there using back roads and just try them out. I know they need to be sufficiently hot to work properly. If they don't work out for autocrossing I'll save them for shows, and eventually, track work. To be more specific, right now I am looking for DOT tires that I can legally run on the street and that combine exceptional street/autocrossing performance. As I check out Roger Kraus' site, it shows the Hoosier TDs to be "Historic NON DOT" (are these radial or bias?) and that Hoosier strongly advises against running even their DOT approved racing tires on the street. It sounds as if Hoosier's lawyers have been involved here. If I decide to get really serious about autocrossing again, I'll consider towing and running Hoosiers, either TDs or the A3S03. I do like the idea of sticking with 15" rims, by the way. They really do look better. I'd love to compare the two before commiting. I do plan on changing toe between street and autocross and I always drive with two hands on the steering wheel, a habit I learned from my autocrossing many moons ago. This is good advice.
Rick: It sounds like you had great success with your TDs. I like the idea of less unsprung weight; I believe the Kumhos are pretty light as well. Four seconds off your autocross times is very impressive. What kind of tires were you using initially? Please don't say Kumhos! ; ) Rich

[rdorman]

Kuhmos



Bottom line here, if you want exception dry weather performance in Cobra OEM type sizes that are street legal you have one choice. TDs. If you go to 17" you have a number of choices (topic better left for someone else!).

The TDs are DOT legal. They where specifically designed for racing classes that require DOT tires. If you think about the difference in mass, say between a Kuhmo STX 275/60 @ 38 pounds and a TD 275/60 at 22 pounds why they are not recommended for street use should be quickly appairent.

There just is not much to them! No tread to speak of, none of those side wall build ups to protect the rims, no extra meat for curbs and potholes, extra meat for punctures, etc. They are intended to race.

With that said, in Ohio you can't avoid all the potholes, although I have managed to miss the curbs so far! I have run straight through varieties of debris such as broken glass and no problems yet.

Also, they are a compromise, They will pick up every rock in a ten mile radius and being a bias ply they do follow and don't ride as well. Not so much that it can't be lived with but it does take a bit of getting used to.

Excalibers tires while a good set don't come in sizes that work for me.

If you are looking for a high performance 15" tire that is DOT legal and will work in the wet and have near stock sizes then join the club! Aren't we all! Just go buy the Toko S/Ts and suck it up like the rest of us!

I think most of us would donate out left testical to get a decent 15" all around tire!

Rick

[snake oil]

I too am on the hunt for a better tire.
Nothing available in combination
sreet use / weekend racer IN 15" nothing at all.

At the risk of sounding completely ignorant what is a "TD"?

[Ant]

Getting a tire to do everything is impossible, its a bit like firearms there is a different caliber for every task.

I have just purchased two sets of Trigos and will run slicks on one set of rims and a reasonable road tire on the other, hopefully that should do it.

I have used BFG 15" and would have to agree they are very average, most of the old muscle car tires are a bit like smokin the bags and not much else.
Raced on Yokohama A008R in a Toyota sprinter turbo and that stuck well but they were in a narrow rim size!

[rdorman]

Not ignorant! Hell, I shudder to think of all the stuff I have learned here............ beleive it or not

Hoosier TDs. Check out hoosiers site. Seems to me if you can deal with a shorter 15" they even have something stickier.

Rick

[badrich]

Snake Oil: Asking questions on this forum doesn't show your ignorance. It makes you smarter! No one has all the answers here, but there are a lot of helpful folks out there who have been thoughtful enough to share their knowledge with us. Check out Jamo and Rick's messages and they will give you some useful information on Hoosier TDs. Hoosier's web site calls them "Historic" race tires. They have four different 15" sizes, from 8.7" to 11.0" wide, bias ply. I'm sure they are great autocrossers, but because of their light weight construction they aren't recommended for the street. I'd like to compare these side by side with the Hoosier A3S04 radials. You are right Ant, you can't get a tire to do everything. So far, the Kumhos still appear to be the most versitile of the lot. Some day I may have something to tow my machine with, and then I'll go with some real race tires and not worry about these piddly compromises, like being street legal, etc. Rich

[Excaliber]

15" does limit the choices. I ran 16" and was very happy with my Compomotive wheels. 16 looks pretty close to 15 visually and allowed more choices.

Also my wheels were "bolt on". Important to me because I DID change wheels with pre-mounted tires for some track events. 16" bolt on Ford rims are VERY easy to come by! I'd hate to buy a second set of "pin drive" wheels just to have around for "racing"!

Ernie

[Jamo]

BTW, Hoosier lists the TDs as tube-type. Neither I nor anyone else I know has ever run tubes in them...sorta ads back the weight you're trying to save. And I did run them on the street for several years without a problem, though I usually went through a set each year. Once drove 60 miles on a corded set after some wonderful spins...lousey trap times but lots of cheers!