R-compounds outside of the track

[H-viken]

Got my hands on some 7" and 9" x 16" Fuchs and am trying to decide what tires to put on them. If I can avoid it I would prefer not having one set of wheels for the track and another for the street.

How many of you use your R-tires "allround"?

At the moment I am leaning towards the Toyo Proxes R888.

[Formerly Steve Wilkinson]

I do have Toyos on a second set of DE wheels, but when my Michelin Pilots wear out, I'm going to use the Toyos on the street. Can't imagine why not. A couple of years ago, after a DE at Lime Rock, my wife and I had to drive home through a real gulley-washer of a rainstorm, in both the 911, on the Toyos, and a Jaguar that I was testing for a magazine. I needed to drive the Jag, so my wife was stuck with the 911. She drove it the hour and a half home through standing water in places and had no trouble at all.

I don't understand why they're marked that it is "recommended" they not be used on the street, though they legally can be. If anybody can explain this, I'm all ears. And hands and feet.

[mkossler]

I had thought the recommendation was simply based on service life concerns. Those R compounds are obviously going to have a pretty limited life on a daily driver. Other than that, I can't imagine why you wouldn't want the highest possible level of performance, which will be the R's for sure.

Anyone aware of another reason?

[Won]

Unless you really push the car on the street like you would at the track, I'd imagine the tires will heat cycle out before they wear out. Either way no reason why you can't, if you don't mind buying tires often or throwing them out with 50% of meat still left because they are useless at the track.

[zeb930]

I ran Toyo R888 235/295s 18" on both track and street this season.. Worked suprisingly well on the street in dry conditions. In the wet you just have to be a little more carefull.. only off-boost driving for me when the tires are cold.. (400hp)

Going to run the same set-up next season..

[JeremyD]

I'd go with the RA-1's = full depth if you do alot of street driving. Shaved if you don't. Many race teams us the RA-1s as wet race tires - that should tell you something.

(I used my RA1's for about 8 months as my only tires and did not have any issues - just more careful in the wet)

[s5uewf]

I used RA1's every day to work and back and to all the DE's I attended for 3 years.
No issues at all, though I tend not to drive my 911 in the rain.
I go through about one set of RA1's per year between driving and DE's.
Have to adjust inflation between street and track!

[Steve@Rennsport]

Originally Posted by Formerly Steve Wilkinson

I do have Toyos on a second set of DE wheels, but when my Michelin Pilots wear out, I'm going to use the Toyos on the street. Can't imagine why not. A couple of years ago, after a DE at Lime Rock, my wife and I had to drive home through a real gulley-washer of a rainstorm, in both the 911, on the Toyos, and a Jaguar that I was testing for a magazine. I needed to drive the Jag, so my wife was stuck with the 911. She drove it the hour and a half home through standing water in places and had no trouble at all.

I don't understand why they're marked that it is "recommended" they not be used on the street, though they legally can be. If anybody can explain this, I'm all ears. And hands and feet.

No reason whatsoever why you cannot use them as your "regular" tires; both for commuting to the track and lapping.

I have quite a number of customers who have been doing this very thing for many many years. Naturally, they were not using Hoosiers,.........just Toyo's, MPSC's, or 048's.

[petevb]

Originally Posted by Formerly Steve Wilkinson

I don't understand why they're marked that it is "recommended" they not be used on the street, though they legally can be. If anybody can explain this, I'm all ears. And hands and feet.

I think its been about 10 years since I've put anything other than R compounds on a Porsche as a primary street tire (I live in California and now have another car as a daily driver). Back in the day my "street" tire of choice was the Yoko 032-R, then later the Toyo RA-1. Both worked well on the street and were still good at the track/ autocross if I wasn't shooting for top time. I'd even occasionally drive Kumho V710s on the street on weekends, though I'd admit that's pushing it a little. I won't driver Hoosier A series on the street- I find they just pick up too much road crap and hence puncture easily.

Over all those years I've only had one issue with treaded R compounds that I'd qualify as a serious:
On one spirited weekend drive through the mountains in '98 I gained enough altitude to encounter a light dusting of fresh snow on the road- maybe an 1/8 of an inch, almost nothing really. Within 100 meters I had to stop dead in the middle of the road. I gingerly opened the door and stepped out, expecting to find the snow hiding a solid sheet of ice! The grip was literally so low that I was concerned about the car sliding sideways off of the crown of the road while stopped- I literally would not have believed it if I hadn't experienced it.

There was no sheet of ice, just a little snow. I later learned that there is a transition temperature below which rubber stops being rubber and starts being plastic, and the snow had rapidly cooled those tires (the 032-Rs at that point) below that temperature. If I'd been on the freeway or in a place I couldn't have stopped I would have crashed, simple as that. Instead I was able to turn the car around and creep the 100 meters back to bare pavement...

Clearly even summer rated tires come with big warnings telling you not to drive them below about 40 degrees, so it's not shocking that an R compound (some of which will crack if even stored below freezing!) would have problems in the cold. It was the scale of the issue that shocked me. Of course it will vary from tire to tire, and it hasn't stopped me from using them as road tires for another 10 years, but from a liability point of view if nothing else I'm not at all surprised they put warning labels on them...

-Pete

[CurtEgerer]

R-Compound tires have no UV protection. Why would they, they're designed to be used for short periods of time and thrown out. I wouldn't run anything more than 2 years old. All R-compound tires I've driven on the street exhibit exaggerated tramlining - just something to get used to but it can be un-nerving in the rain.

I've had 2 failures on R-compound rally tires on the street. Both were older than 2 years and the rubber was beginning to harden.

[Todd Simpson]

I use my R888's "year round".

Here in my part of the world, that means temps rarely below 32 degrees, I never drive in the rain and always trailer to the track.

If you will *ever* be driving in snow, or you will have consistent cold temps, I would not use these tires.

If you're driving in rain, well, R888's will be pretty good when new but when the tread is gone, you are asking for trouble.

Here's some cold temp info.

[Dantilla]

I've driven to and from our autocross site plenty of times on Hoosiers. Only when dry.

It's only about a half-hour away, and sure beats lugging an extra set of wheels/tires and the jack in the 911.

[unclebilly]

I have driven my 032s on the street a few times.

I want to point out a falicy in Curt's post above. R-Compounds will not crack if you freeze them and let them thaw out without moving the car.

I didn't get my r-Compounds off of my car before temps hit -16°C (3F). I thought my tires were shot but I called Yokohama anyway to ask. I was told that the tires would be fine as long as it wasn't moved at all. As mentioned above, they drop below the glass transition temp but unless the loading changes, they are ok.

[DYB]

I have the R888's for the track and since the car gets occasional use on the road I leave them on. But unless you have full tread on them I am very careful of them in the rain.

If I was doing alot of non track miles I would not leave them on. They certainly do not add to the comfort factor (harshness and noise) if its a daily driver.

My other concern would be heat cycling them to often if used as a daily driver.

Any one have any idea on how often a R compound can be heat cycled before it starts to compromise its grip ? Obviously different brands are affected differently, but it would be useful info to have.

[unclebilly]

I would strongly suggest that you research the toyo RA-1s before you commit to them.

I never ran them but all of the guys in Solo 1 this year that ran them hated them and they came apart prematurely. 4 - 5 guys had the same experience on various cars.

I will be running Hoosier R-6s next year.

[benp911]

I don't even own street tires for my car. I run mpsc on the street and these tires are amazing. I would reccomend these tires for a second car anytime.

[MT930]

I've run MPSC in the summers the only time I drive the car. They are great on warm dry pavement in fact they are excellent they do pick up a lot of road grit. They are spooky on moist pavement, they are scary on standing water. Sometimes you get caught in the rain to or from the track you just have to tip toe out of it. They ware very fast so it get expensive.

They have their limitations. They are great in the right climate or season. I will always have a set for the track however I am thinking about going with a high performance non R tire for the street it's got to be cheaper they only have so many heat cycles after that they melt away.

[EarlySport]

I run all but my daily driver on R tyres and they do mostly street duty with track days in between. In recent past that's Bridgestone RE55's, Dunlop R's, and Victoracers. I do find the biggest difference is the increase in ride harshness from the stiff sidewalls, and they can be really noisy.

As far as heat cycling goes, I'm sure in 99% of street driving I never get my R's up to temperature, so I can't imagine a normal street drive heat cycles them..

[Quicksilver]

Originally Posted by CurtEgerer

R-Compound tires have no UV protection. Why would they, they're designed to be used for short periods of time and thrown out.

. . .

Carbon black is added to rubber as a UV protectant. Natural rubber is white.

That being said:
Racing tires are not designed for lifespan. I have never had a set of R compound tires last 2 years. And with the very large mass of rubber on a ralley tire I suspect it would be more prone to heat build up in the carcass that could lead to separation. I would be interested in the tire pressures and operating conditions before the failure.

More so, after having 2 failures of this type I would seriously try and corner a tire engineer at an automotive event. They probably wouldn't respond to an email (because of liability issues with putting something in writing involving a failure) but if you get one talking in a casual setting they can probably shed a lot of light on the failure.
_________________

BTW - On the 911 I have run nothing but R compound tires on the street since 2000. I've used Yokahama A032s & A048s, Kuhmo Victoracers, and Nitto NT-01s.
Even when cycled out they produce better traction then the 'high performance' offerings. The Nittos are my favorites but they have serious issues with anything but dry roads. Their resistance to cycling out and to getting greasy when over heated is great.

I personally found that an ultra high performance street tire had such low grip compared to the R compound tires that I ended up sliding around and just wore out the higher mileage tires. (Your mileage may vary) Tires are the largest single contributor to handling. Less then wonderful doesn't make sense on a 911 to me...

Also...
I have only had one "sticky rubber" related failure: I had the 'sticky' of the front tire pick up a 6" snap-off type utility knife blade and throw it into the rear tire. It was driven completely into the rear tire with out breaking at any of the snap-off points. It left a 1" wide cut right through the middle of the tire right through the steel belt! The tire went down in a couple seconds and when it was dismounted the complete blade was found inside. Completely freaky.

[beepbeep]

Hej!

R888's work to/from track but it's nothing I would use daily. They are very slippery in wet, noisy on asphalt and generally don't work well before warmed up to at least 50 deg. C. Also, any sort of "track" camber will wear them down quickly in daily use. When going to track, I usually replaced at least driving wheels with stock tires and loaded R-tires into trunk, to be swapped at track.

I drove on Dunlop Direzza's "hard" last year as well. They could be driven on the road but it took lots of attack to get tire temperatures on the track.

So my opinion:

R-rubber for track, Yokohama or Dunlop for the road.