James Achard

All,
After all that has been happening with new R-compound tires I thought it might be a good idea to compile all the information on one thread. My goals for this are twofold;

1. To get all the info in one spot.
2. Get enough folks onboard and present the info to the tire companies in the hopes of them making more sizes that fit our needs( I know I'm dreaming here but what the heck..)

We represent a huge market and it would be beneficaial for all of us to have tires that work and are offered in the sizes we need. Below I have put down what I have been able to summarize about each tire in my wee racer brain, in no particular order.

Toyo Proxes RA-1 Pros; cheap, good adhesion and great in the rain. Come in a good range of sizes though fall short in wider sizes in 17". Seem to work better on lighter cars, with weights being 2800lbs or less. This figure canges car to car and driver to driver. Con's; Not as fast as Hoosier or Michelin( subjective here too) and heavy. Not many sizes in the wider 17" range and tall.

Kumho V700; Similar to Toyo though not as fast. Pros; Cheap, good sizes available and good wear. Seem to work better on lighter cars. Cons; quality issues, tires drop off in grip very quickly.

Kumho V710; Recall, need I say more.

Avon Tech R; New, no Data but zero sizes available. I spoke with tire rack and got nowhere with any info on when more sizes will be available.

Dunlop Super Sport Race Seem to be good. Pros; Good grip and life though not much data to support this. Cons; bad size selection.

Michelin Pilot Sport Cup; Pros; Fast wear well and good support at the track. Fast tire and good in the damp too. Cons; Sizes limited and don't do well in the cold/cool temp ranges.

Hoosier RS304 Pros; Very mixed reviews Pros; Very fast yet only last for an unacceptably short time. For a tire that was touted and built to last longer, a real letdown. Cons; see above weighs more than the o3 and has a shorter life.

Pirelli P Zero Corsa; Seems to be quick for some but is not widely used. Great if you have huge wheels but once again not many sizes offered in 17 and less rim diameters.

Yokohama A032 Pros; Great DE tire, reasonable priced and sticky. Cons; loud and not really useable for racing.

If I have left any out let me know and add accordingly. I'm sure some of the things I have mentioned are not 100% correct but this is still a fairly subjective matter. My goal from this too is to get a petition going and have it circulate at the club races. What I would like to be able to do is get a list of all the drivers out there who want a better selection etc. and submit it to all the tire companies and see if this helps our cause. I realize they have marketing depts. but they just don't seem to be doing a good job. Please feel free to make any suggestions etc?

Cheers, James

Brian P

For what it's worth, I haven't found the MPSC's to be bad in cold weather. Sure, they are bad when the tire is cold, but after a few warmup laps, they seem to do fine no matter what the ambient temperature is. This was based off some experience in 35-40 degree days (with snow coming down). Of course, maybe this just means I'm slow no matter what the weather is...

If we are trying to make a spreadsheet, perhaps it would be useful to distinguish between what a DE driver wants vs. what a racer wants. Seems like a DE driver would want something with long life and tires that have about the same grip during that lifespan. I've heard the Toyos are particularly good in that respect. The MPSCs seem barely better than normal street tires after about 10 DE days.

Mark in Baltimore

I agree with Brian. In my heavyish 993, I found the MPSC's stuck very well when I did the G&W Fall Fling last November and this years chilly Summit Point DE in March, both events having max temps of 45 degrees, min temps of 28 degrees.

DrJupeman

I'll agree with Brian and Mark regarding the cold performance of MPSCs with one add on... I found the MPSCs gripped well at Road Atlanta in January (temps 35 degrees or so). I also find they stink for autocrossing. I suggest the key is getting heat into the tires, not necessarily the ambient temperature. At an autocross, even on a hot day, there is simply not enough time to heat up these tires! But given a lap or two on the track, I've found they've done well at relatively low ambient temps.

DGaunt

I know there will be many who reply about larger sizes, so I will take it upon myself to represent those of us who have no fender flares and 15" wheels. We need some 'R' compound 60 series tires for both DE and comp. some vintage racing requires the 60's and they are not currently available. Good luck in getting the message out to the tire companies, no matter what your needs are. Someone should!

JC in NY

While I am not one to blame equipment for driver error, I have seen quite a few wrecks in cold weather with MPSC tires. One thing that is consistent is that the drivers reported the car "let go" quite unexpectedly. I am not trying to prove anything or indict the tire , but I am looking at some events that seem to have something in common. My premature conclusion is that these tires are diabolical when the conditions are cold or cold/wet.

Bill L Seifert

Great comments by all. What we need is a tire that is available in all sizes, like Hoosier, wears like MPSC's, has the stickiness of the S04's during the 2nd and 3d heat cycle, and is priced like the Khumos.

I'm dreaming.

Bill Seifert
1983 944 Race Car

trumperZ06

Goodyear GS-CS Dot " R " tires available in 17 and 18 inch ... not sure about all the other diameters.

IMO... Corvette sizes.... Stick almost as well as Hoosier S03's last longer.

GlenL

What retailers or web sites handle the Toyo's and Dunlops?

Eric in Chicago

JC I agree,
Ran MPSC for the first time last weekend at RA, shaved, heat cycled 55-60 degrees outside, correct tire pressure, almost looped it on the warm up lap. Lap 1 hot was frightful, lap 2 the same. By that time all confidence was shot. I would rather run with 2 year old, tired hoosiers. I dont know how guys race on these. 3 laps warming them up? Better be a hell of a driver to make up all the spots your going to give up while waiting for them to get hot...
On the other hand, corded a set of 285 04's heat cycling them. Stuck between a rock and a cold place...

Matt

I haven't been able to get the MPSC's to work on my 2780# low-hp 924S. I believe the problem is that I can't get enough heat in them, and narrower MPSC's would work somewhat better (I run 225/50/26 front, 245/45/16 rear). I can do 1:05's at Lime Rock on non-shaved Kumho Victoracers, but can't get within 2 seconds of that (an eternity) on the Michelins. Tried different pressures, camber, etc...

I think if I could overcome the "wider is better" mindset, I could get the MPSC's to work, but I have too many other things not related to cars to put the money and effort into. Michelin hasn't been very helpful in trying to figure out how to make their tires work, and at the prices they get I'm not inclined to do too much experimenting at my expense.

I'd sure like to pick up a second or three, but until Hoosier straightens itself out and makes good on its claim to give us a fast tire that lasts more than one or two days, I guess I'll stick with Kumhos.

Matt

PT

FWIW & I might be the minority - I tried a set of Toyo RA-1s and went back to the Victor Racers V700s. For me, they have better grip, takes much shorter time to get rid of the initial squirmy-ness (I bought & used both un-shaved). And the Kuhmos are cheaper than the Toyo.

Bill L Seifert

Last summer we ran the 10 huers du Mon at Gingerman, on MPSC's. The temp was in the low 70's. I didn't run the first session, but the guy that did raved about them (Good not bad) and later bought a set for his 924S. The size we use is 225-50-15. One of my sessions was 1 hr and 15 min in the wet. I thought they worked very well, and by then the air temp had dropped. We just ran about 6 psi over dry pressure, and they were very predicable.

The guy I found out about MPSC's was Denny Voss, who runs NASA in the midwest, and he loves them. He said his fastest lap was on his 28th heat cycle. We are going to run the 12 hours at Nelson Ledges in July, and use MPSC's. But after that I will probably use Kuhomo Exttas, for sprint races, but thats because the guy that beat me at Memphis last week used them.

Decisions, decisions.

Bill Seifert

1983 944 Race Car

BrianKeithSmith

I agree with TrumperZ06 - Goodyear GSCS DOT Slicks.

I never could figure out why more people didn't run these tires.

My only problem is that in the last year, I've had a heck of a hard time getting my hands on them. Every time I'd call Bob Woodman to order some, they were all "committed" by Goodyear to some big SCCA event. So I ended up running R3S03's and eventually R3S04's (which I didn't have an issue with, but then again I only put about 140 miles on them).

But the Goodyears are good tires. They wear well, are consistent, and come in the sizes I need (Unlike the MPSC's).

Brian

Dave in Chicago

There is a detailed 45-slide PowerPoint presentation from Michelin on the mpsc's that specifically speaks to design, fitment, care/feeding as well as recommended set-up for A) older, lighter 911's, B) 964's, and C) 944 series. I can't remember where I tripped across it or I would point y'all there.

If someone would like me to forward it (1.7MB) and perhaps even post it, drop me an e-mail at teamswanson@ameritech.net.