as copied from the GGR rules book:



given the choice, what would be better and more cost effective??

wide street tire/wheel
or
7" wide rim with race tire

are there DOT tires "close" to being a race tire???

let others chime in here.. but race tires defines as slicks, and slicks are stickier....

dot tires includes hoosiers and the like.. yes they are fast, but they are still not slicks...

which would be better?... depends upon how wide you would go with the hoosier I suppose....

alignment settings between a slick and dot, would be very different too....

b

Are you running in SCCA if so what class? going to slicks will bump you up from street to modified.

- Garold

sorry, PCA only right now......for some of the local open track events, the car is not really classed as much as the driver experiance and I'll be in the slower run groups for a while

if it's DOT R compounds, then it's a "street tire". basically, RA1's, and Hoosier R3S03's or R4's are legal because they are DOT approved.

"Race tires" are way different. and extremely sticky! They do not have any "DOT" ratings on them

i was not sure if all they do is add a water channel to make a "race" tire into a DOT tire...I'm guessing not now

huge price differential between the two???

Oops, forgot to mention. I'd get some Hoosier R3S03's. Haven't heard much on the new S04's yet.

I'd say run Goodyear cantilever slicks. They were made for 7 inch rims but are a little over 9 inches wide at the contact patch. They have very very stiff side walls so the flex you get with the Victoracers and other "DOT" approved race tires is eliminated. This is very easily seen when I follow a a 914 or 911 with the DOT tires and I can actually see the car dancing from the tire movement on a fast banked track such as CA Speedway. The down side is they are a little more expensive and take a lap to get really sticky as the Victoracers are good when the green flag drops.

Mike

There's really 3 levels:
Street tires
DOT-R tires
Race tires

Street tires are usually referred to as tires which have a wear rating of 120 or more. You will not be competetive with any of these tires.

The DOT-R tires are in between street and race. They are DOT approved, so they are officially street legal, but they are not tires you would want to drive on the street. Wear rating is usually 50. They will not be as fast as race tires, but are competetive and are considered the best bang for the buck. Lots of people run these.

Race tires are just that. Very sticky and fast, but wear quickly and are expensive. Don't buy these unless you are a good enough driver to need that extra edge to come out on top.

Demick

thanks Demick !!!!

As usual others have more clearly expressed than I am able..

but mike I just wanted to comment regarding your mention of the rain channel..

dot certification involves quite a bit more than a rain channel... There is a federal testing process with load/time/heat etc.... Certification is a pain in the butt, and I don't imagine its cheap either... Sorta like crash certification for cars... a lot of low volume manufactors don't want to/can't afford to go through it...

The full race slicks haven't been through it... doesn't mean they will blow up or kill you ... they may or may not pass the test.. but the differences are more than a rain groove.. There are a few tire that fall into this inbetween.. for example the hoosier rain tire. Its compound is more similar to a dot tire than a slick.. its composition and side wall is also more similar to a dot than a slick.. yet hoosier didn't bother to put it through certification probably for cost reasons.. I've heard that it was actually faster than the 03 hoosiers, but didn't qualify as a dot for pca stuff, so it gets classified as a race tire even though it is truly not built like a slick...

true slicks are another world. very different in every way.. most will heat cycle out before they wear out. Go with the DOT... use something cheapish to learn on. My experience with 2nd tear level tires has shown that the victoracer works better with a 2000lb car where as the yoko is superior with a 3000lb car..... just buy one of these consistent and longer lifed tires, and then do the driver training route.

b

with Demick

The first time I used a DOT-R tire (BFG R1) was at Laguna. I drove the car up there on real street tires then switched over to the DOT-Rs. They were plenty sticky for DEs. I'm sure the faster you'll go you'll want slicks more, but until I reach that point DOT-Rs are my choice.

i drove my C2 on the street with Comp R1's for a few thousand miles when I first got it, awesome grip..then I put on the Kuhmo 712's since the car is mostly just a "driver" and I knew the rain was coming soon at the time....what an f'n disapointment with the Kuhmos (and not just due to the blow out)

Mike,
I have offen debated the race slick vs. autox R with others in the past. I even posted the question a month or so ago.

If you are speaking of ONLY autox use, I think a shaved, R rated autox tire will be quicker. Here is why,

1. Slicks in our size are not made in the sofest of compounds. Check Goodyear's race tire website. They have a table that has the compounds listed.

2. As stated earlier, slicks take time to come up to temp. On a autox you don't have this time to wait.

3. An R rated autox tire is designed to heat up quick.

Now this all changes when you have wheels and fenders that allow you to mount the softest compound. But of course, you just moved up to a differnt class.

The debate continues....

Paul

The differences between "race tires" (slicks) and AX specific tires has become increasingly blurred.
I agree with Paul except:
AX specefic tires don't need to heat up to get their grip. They are sticky righ out of the box.....or so I am told.
I won't have personal experience with this for a couple weeks, but I trust the folks telling me this.
The new Hoosier are like a "qualifying" slick. Dunno if they would last more that 2-3 laps on a race
course....less for the Kumho's if recent reports are true

In any case, I would recommend Kumho Victoracers..205 X 15 or 16 as a good place to start. You're gonna get
your head handed to ya regardless....don't take it personal, it happens to everyone.

thanks, Paul, JP and everyone else...it seems that the "regular" auto-x tires in the 205-ish size would be best for my car, especially since I am just starting out....

Check out Michelin's Pilot Sport Cup. Very popular at our local DE's. Very close to the Hoosiers in grip, but they don't poop out after only a dozen heat cycles. Some guys have gotten an entire season out of a set (though we don't get as many track days out here as you CA guys do). Just don't start flogging them until you've warmed them up; probably not a good AX choice for that reason. Street legal enough to drive to the track.

Truthfully Mike, I'd encourage you to simply run street tires for the first year or so. You won't be competetive anyway for 2 reasons:

1. It takes awhile to get the car handling sorted out and to your liking
2. You need to learn how to drive (no offense intended). Being a 'good driver' on the street doesn't mean crap when it comes to the autox course. Being competetive at the autox simply takes some experience and time behind the wheel.

I think that you learn much faster how the car handles at its limits with street tires. This is helpful both in sorting out the car's handling as well as your learning how the car handles. I ran for 3 seasons on street tires before making the transition to DOT-R tires.

Yes, you will be faster with DOT-R tires, but since you aren't likely to be competetive either way (at first), you might as well save the $700 and learn on street tires. Besides, it's always a convienant excuse as to why you aren't competetive!

Demick

Hey Demick...

points well taken and not offended at all

it might be safer with the street tires as well, since the adhesion limit will be lower so I am "forced" to slow down until I know what to do at the higher speeds.......

Demick makes a good point, but with the following caveat. Some street tires have lousy recovery characteristics. I have some Yoko Intermediates that are pretty good. I had a set of Dunlops that were terrible. The Victoracers are very catchable.

Since you have a turbo, this is even more important.
In AX, boost is not good unless the car is pointed straight ahead when it comes on. Otherwise....lurid slides look cool but aren't the quick way around.....assuming you can catch the slide.

I ran 4-6 AXs on street tires.....the Dunlops....before saying "the hell with this" and got some Vracers.....don't feel I missed much.

It's really not any safer (a well run autox is a very safe environment regardless). But I do think you will learn faster. With street tires you will reach the limits of the car sooner. They will also provide better feedback in many ways. They 'let go' fairly gently (competition tires tend to let go pretty abruptly) so it is easier to drive a car at it's limits with street tires than it is with competition tires (I disagree with JP on this point). This allows you to learn how the car behaves at it's limits. In my opinion, it's also helpful in setting up the car. Oversteer and understeer are likely to be more pronounced with the street tires.

Besides, it's really fun (although not fast) to go slipping and sliding around the course. Carrying a controlled power-on 4 wheel drift for 100 feet or more is REALLY fun - and something you are only likely to do on street tires.

Demick

isn't Mr Demick a GREAT part of the 914world.com???

Hey Scott - when are we going to see you show up at an autocross? There's one this Saturday at Alameda - which is the best venue in the entire Bay Area.

Demick

I don't really care for autocrossing, I did it 20yrs ago when I had a Black 2.0

I liked the *flow* of de/time-trialing alot better.


To me, auto-x is...
Press the gas as hard as you can, and then the Brakes as hard as you can.
Repeat.

I just didn't enjoy it, I guess I should try it again.

hey Scott,

I too thought auto-x was basicly like a light switch...on/off
stab,steer,stab..etc...etc...a pretty much mindless task


but now learning more about how to drive and the car, I found out that auto-x can be more of a mental challange and it makes me really think what I am doing and what the car is doing and why...

I'm not sure if I'm alone or not, but I enjoy the conversation I have with my myself while out there on the course.."slow down, hit the gas...turn, too much, correct...easy on the gas, now hard on the gas, lift........did I beat my last time?, did I beat Brad???"

Mike,
do you still have 4 lug wheels? If so you can try my panasports with Vracers on them. I AX'ed with street tires for a few events and it really sucked (the tires did as well, better tires would have yielded better results) . VRacers are great in my opinion. They last, are affordable....

thanks for the offer Chris...one little problem...my car is 4x100 bolt pattern

so your rims wouldn't bolt up to my car............

Would definitely "steer" away from the Pilot Cup Sports, as they are really designed for heavier cars like the 993 or 996. We had a tech session last month and the Michelin guys were there showing off the newest version to us track junkies. I mentioned something about heavier cars and they pretty much flat out agreed that a 2kish lb car is not the best platform for running those tires.

Great advice on the driver/tire progression so far!

Hoosier rain tires were not DOT certified as the tread was hand cut!

I agree that decent street tires are a very good starting point for autocross. Especially if they don't have a bunch of tread. Ask me about auto crossing a Mercury Grand Marquis rental if you want to know about tearing tread off the outside of a tire.

Street tires that have decent recovery can teach one a lot about car control. With sticky tires you can end up going so fast that if you make a mistake you pay for it right then and there and the opportunity for learning is gone or greatly diminished. This is why skid control is taught on slick surfaces. Things happen more slowly and you have time to learn the proper behavior.

Kumho Victoracers are quite sturdy for an R compound tire. Once you are ready to move up from street tires I say start there. They work well on the car in my Avatar and that thing weighs >3200lbs with me on board.

Joshua Skinner

Jump in to the Kuhmos, if you are going to learn how to drive an AX then go for the sticky tires. Street tires are ok to learn on if you have a stock suspenion but if the car is set up at all go for it. Its the same learning curve its just more fun on Kuhmos as you won't spin out quite so much.



Geoff

Hey Mike. You've already autocrossed at least a few times and attended a school didn't you? I don't think competency is an issue. I'd say it's a toss-up. Personal choice. You'll have fun either way. I'd probably base the decision between street or race rubber on the number of events you think you'll do each year. If you're sure you'll run enough events to justify it go for the race tires. Otherwise I'd stick with good street rubber and save the garage space.

I would like to have race rubber, but it's fun even with my old Dunlops. Here's a clip of one of my runs two weeks ago at the drivers school the local club did. It was fun (duh!) and I learned a lot. See, even anemic 1.7's can have a good time! My point is, either way you'll have a good time. It's just plain fun any way you cut it.

-Ben M.