R compound for M5 - The Unofficial BMW M5 Messageboard (m5board.com)

M5ROKIT · 7th February 2005, 20:42

Seriously considering going to track only R compound tires for my M5. Anybody out there done it? What brand and sizes all around? I have 18" rims with Michelin PS2 all around now.

Redshift · 7th February 2005, 21:04

Toyo RA1 or Dunlop SP Sport Race work well. If you are a novice or even intermediate, stick to street tires until you are sure of your abilities, then switch to R-comp or slicks.

Nolift911 · 7th February 2005, 21:34

What Redshift said. I would not run R compound tires unless you are expert/instructor level with many track hours under your belt. Yes you will be faster and yes you will be more confident in your abilities along with the car but...

Once those R's lose adhesion you better be skilled like Shuey to save it otherwise you will be in a world of hurt along with your M.

I have seen this first hand at the track from M3, Vettes and S2000. They look great and fast right up to the point of crashing.

-Jeff

gsfent · 7th February 2005, 21:39

Quote:

Originally Posted by Nolift911

What Redshift said. I would not run R compound tires unless you are expert/instructor level with many track hours under your belt. Yes you will be faster and yes you will be more confident in your abilities along with the car but...

Once those R's lose adhesion you better be skilled like Shuey to save it otherwise you will be in a world of hurt along with your M.

I have seen this first hand at the track from M3, Vettes and S2000. They look great and fast right up to the point of crashing.

-Jeff

Just as importantly, good tires can mask bad driving. You will learn more on street tires that slip and slide than R compound tires with better grip. For the guys that have crashed on R compound tires, I would suggest some instructor error is involved. Students shouldn't be running on the ragged edge (at least not with me in the car!!!!

). If the students are soloing, that is different, especially late in the day when the "red mist" sets in and there is no instructor to rein them in......

Regards,
Jerry

M5ROKIT · 7th February 2005, 22:14

Thanks for the warnings! I do have a lot of track time and run in advanced groups and solo. However, I AM out there for fun and NOT shunting. What about a compromise like a Michelin Pilot Sport Cup? I don't think they make it in stock wheel sizes though.

Redshift · 7th February 2005, 22:27

MPSC is less of a compromise than you think, only because it gives no feedback (i.e. squealing) like other tires do. It may have a predictable traction limit, so if you are advanced enough to feel it, the MPSC should work okay for you. You might need to consider adding 2 rear OEM wheels up front to do something like this.

Nolift911 · 7th February 2005, 23:23

Quote:

Originally Posted by Redshift

MPSC is less of a compromise than you think, only because it gives no feedback (i.e. squealing) like other tires do. It may have a predictable traction limit, so if you are advanced enough to feel it, the MPSC should work okay for you. You might need to consider adding 2 rear OEM wheels up front to do something like this.

Great point! I was in an S4 at Summit Point with an instructor and he was running R compound. He was "showing" me the track and then we went into the carousel and he began showing me the agricultural side of the infield areas, quite a ride and no harm done but...

I'll never forget the eerieness of it on the R compounds - no noise, no drama, just like the hand of god scooted the car off to the infield and we spun. We came to a rest and looked at each other like wtf? Well that is R compound.

I have a number of events under my belt and solo's also but I would not wear R's unless it was a track only car that I would not care if it got bent. With R's it is not if but when you off the car and hopefully it is all grass and no hard walls.

Personally R's are meant for racing; period. You will become so much more of a better driver on streets anyway. I like the fact that I can pass some R outfitted cars on the track in my 911 with my KD's. Granted they are at the limit where street tires go but they do make a fuss when you reach the limit and I know it is time to cool it. Plus I get to drive the car home nice and straight

-Jeff

stever · 7th February 2005, 23:28

I've switched from PSCs to RA1s. Didn't think the PSCs lasted as many heat cycles as i'd anticipated and they are very sensitive to tire pressure -- but fast when they're new and you've got them at 32-34 PSI hot.

RA1s are very predictable and not as fast -- can't say for sure about life yet.

Advantage of track tires is they get so greasy when hot -- particularly important if you track during hot weather -- other advantage is you're not buring thru your street tires

Redshift · 8th February 2005, 00:20

Jeff, your experience is the main reason I went back to R-compounds instead of slicks on my Z06. I had a student in the car with me late last year and the rear end came around quite abruptly with no noise or drama, and scared the bejeezus out of my student (not me - I just corrected and kept going). He screamed "Why didn't the tires make any noise! That was wild!" and I explained that very sticky tires tend to make less noise at the limit (and over the limit) than street tires. The grip was incredible with those Hoosiers but it's not quite as good a learning experience for the students, and for a car that I need to drive home in, I decided to switch back to something that makes noise

Murph · 8th February 2005, 00:58

I highly recommend the Falken Azenis tires for track driving. They last a long time, are cheap, STICK great (for a street tire), and howl progressively to let you know you're getting close to the edge. Unfortunately the largest size they come in is 245/45/17, so they'll only work with track rims of coure, plus you'd be giving up some width at the rear on the M5. I used this size on my 540 & was happy with them, and also on my E30 before switching to RA-1's.