paradisenb

I drive an 87 911 Carrera. I shopping for tires for AX and DE. Would like to buy one set and use for both. I do more AX than DE. Has anyone used Kohmo Victor Racers and michellin Pilot Sport Cups? How do they compare? What are the pros and cons of each? Does one provide better grip at the expense of ware or vise-versa? Other opinions about special event tires?

NJ-GT

MPSC. Big no for auto-x. They have less grip than a good street tires, and they will never get hot in an auto-x. For the track they are great.

Go with Victoracers, Ecsta V700, Toyo RA-1.

RA-1 last longer and it's more consistent. The Kumhos have better traction at auto-x (just a little bit more)

RJay

The best compromise IMO is Hoosier track tires (RS03/4s), particularly this time of year when the tempatures are up. Cups don't heat fast enough, Kumhos (at least the Ecstas which have on my 996) at very good at AX, but seem to give up a bit (get greasy) on the track when they get hot. I've run Hoosier 03s both at AX and track on my 911 RS 3.6 with success. This year we put AX 04s on the car, the difference in grip is noticable, but I doubt its worth more than a 1 second in 60.

BGLeduc

I can confirm that WRT my Victoracers as well.

My PCA region likes to set our autocross run groups so that only 4 cars are running at a time. By the time you finish your lap, you are almost ready for the next.

After two hot laps, there is a definite loss of grip, particularly in the front. Not sure if thats because the tires are just getting too hot, and thus the pressures are too high, or just a characterisitc of the rubber lossing adhesion, but its quite noticeble.

I actually chaired an autocross this past weekend, and instituted a 10 car run group. Made a big improvement for me. I had good grip straight through all my runs, and my last lap was my best.

BGL

Z-man

I've used Pirelli P-Zero C's in the past and now I'm using the Toyo Proxes RA-1's.

The Pirelli's are very durable, but don't offer as much grip as the Toyos do. Don't know about the wear on the RA-1's yet, since I'm fairly new to this tire (1 DE event, 2 autocrosses). But so far, I like them much better than the Pirelli's.

-Z-man.

paradisenb

How long will Hoosiers last?
In my class, P15, there is usually an interminable wait between runs. The tires will almost always have time to cool. I have ruled out the Pilot's. Don't heat up fast enough, for AX, is a common complaint. I guess I would consider Hoosiers since they could provide use for both AX and DE. My concern is their short life span. I would like to have a tire for at least a couple of seasons.

PedalFaster

Hoosiers lose grip well before they run out of rubber -- if you want a tire that lasts a couple of seasons, use another brand.

Steve

BGLeduc

I can say that the Victoracers tend to keep decent amounts of grip right to the point where they cord. And as a bonus you can drive to the event on 'em.

And on a cold day, the Hossier guys will be wishing that they were on Kumhos.

Of couse on a warm day, the Hoosier guys will be whuppin' your butt.

BGL

RJay

Hoosiers are certainly the most expensive option. After last year running R3S03 at both AX and track, I bought yet another set of wheels and mounted a new set of A3S04. The AX tires are the ultimate (car took FTD by 3+ seconds last weekend, first time out with the new 04s!). My car is pretty light (~2200) so wear isn't as pronounced as it can be with heavier cars. In any event trying to find one tire that will do it all, is obviously unrealistic. The Rs can handle the track and are a match for the Kumhos at an AX at normal temperatures. They are expensive, they have a limited number of heat cycles, and they're not optimal in all conditions. But in a single tire they are IMO, the best option as the are very competive at an AX and work well at DE.

If your serious about AX & DE, the fact of the matter is that you need at least three sets of wheels and tires. AX tires (Hoosier or Kumho), DE tires (Michelin Cups) and rain tires (Unshaved Kumhos, Hoosier rains or your favorite street tire). I haven't had any experience with the RA-1s directly. I know some who claim they are good at AX and Track as well, but I reiterate there really isn't one tire that will do it all, in all weather conditions with long life for short money etc... you have to figure out whats important to you and go from there.

Petevb

I'm starting to quantify how much of a time difference some of the different tires make at an autocross. I thought I'd throw my experience out there and see what others think:

I've run most on yoko 032Rs (H compound), which are probably regarded as the slowest of the R compound tires at the AX. At the other end of the spectrum I just got a set of Hoosier AS04s on a 2nd set of rims- probably the quickest of the bunch. Unfortunately switching back and forth between the two tires really requires significantly different setups, with the hoosiers requiring stiffer springs and a more aggressive alignment. This means a "back to back" test isn't going to have both tires at their best. That said, bolting the hoosiers on with a setup more optimized for the yokos showed a 2 second gain on a 50 second course. I think there is at least another 1/2 second if the setup was optimized for the hoosiers. Not too bad if it’s right...

All the other common R compound tires are probably going to fall within this 2.5 second span. Slowest to fastest, at an autocross I’d bet (I have not run them) they would be:
Yoko 032R
Michelin Pilot Sport Cup (take too long to heat up)
Toyo RA-1 (also want to get hot, but not quite as badly)
Kuhmo V-700
Hoosier R compound
Hoosier A compound

Wear wise, they probably go in about the same order, with the Hoosiers As lasting around 40 runs, and the yokos perhaps 4x that (??) depending on how hot you get them.

I’m getting a set of the Toyos to replace the Yokos- I’m guessing they are about half way between the yokos and hoosiers in terms of AX speed, but they wear much longer than the hoosiers and can be driven to events.

I’m an above average driver in a light, fairly powerful car (2200 lbs, 255 hp).

BIG-BRO

I ran MPSC in A-X for the first time this past weekend, and from my standpoint they did OK ! Yes, it's a compromise of wanting a tire that would last longer, that I could also use for D.E., and I was not as worried about getting the most time advantage out of them. (Still working on the DRIVER skill part of A-X)
In cas of NCR-PCA A-X at Devens last weekend, it was a fast course (like 80 MPH in longer slalom) so they probably did get the advantage of some heat. The pavement had just dried from rain, so track temp was down.

My car has weight that may help heat them (993-C4S, so about 3100 lbs, oops plus driver and co-driver this past weekend)

I may have finished 5th in my class, but my car with the MPSC's did finish first in the class in a more experienced driver's hands....

I just have to get "braver" to push my car further to what I know first-hand it will do.....

M758

I have used Kumho Victoracers for autocross and DE. Loved them. I have found the Toyo RA-1 to be better at racing and DE since it lasts longer ( many more heat cycles), but it seems to be a bit slower at Autocross.

I have never had problems of Kumho's over heating especially at an autocross. I have never put enough heat in the tires to do that. They have also done well at DE days. Even on 100F+ Air temp days.

I did most of these run a 2400 lbs 944. Those of you that have had issues with Kumho's what pressure are you running?

I would run 32- to 33 HOT on the tires for DE and Racing. I tend to start at 30 cold for autocross. These pressures are MUCH lower than hoosier, Toyo, or MPSC pressures.

joey bagadonuts

Similar experience. Actually finished Top 10 with Cups but had -2 degrees of camber. And for the track, the Cups don't get greasy like the Victoracers after 15 minutes and will probably last twice as long if you buy them heat cycled.

Downsides. They're awful in the rain and the sizes are less than optimal, IMHO. Amongst 17" R compounds, the Cup feature the narrowest 225 and widest 255 = noticeable understeer tendancy. For comparison, here are the various sectional widths available for a 225/255 17" combo:

Tire F R
===== === ===
MPSC 8.9 10.7
Victos 9.2 10.6
RA-1 9.3* 10.2
Corsa 9.5 10.3
A032 9.4* 10.1

* Only 235 front available

I think the best autocross setup for a Carrera would have you running the same size tires front and rear but if you're going to the track, you may want the 225/245 Kumho's.