Hankook RS-3's as track tires on an E36 M3

[Level8drummer]

Hey yall, I just wanted to review the Hankook RS-3 size 255/40R17 tire that I've been using on the track, with a square setup on my E36 M3. I have done no weight reduction at all, as this car is also my daily driver. I'm an instructor and I do about 10-15 track weekends per year. This is the thread on how I set up my car:

http://forums.bimmerforums.com/forum/showthread.php?t=1593389

So these tires are now almost corded, they're bald and I have rotated and flipped them to wear them evenly across the tread. I got 6 track events out of them, 1 at Carolina Motorsports Park, 1 at Roebling Road Raceway, 1 at Barber, and 3 at Road Atlanta. And probably 6-8000 miles driving on the street.

They have been great tires, no complaints. My goal was to pick a tire that could be used on the street, and still be used on the track. Until this past weekend, they didn't overheat unless they were pushed very hard with lots of slip angle. This past weekend at Road Atlanta (92 degrees outside) they would start to get slower 3 laps into a session. I determined this with GPS telemetry and lap times.

As far as heat cycling, I do not know if I noticed a difference over the course of the life of the tire. I have done some setup changes and the best test will be when I slap a new set of the same tires on next month and do another track weekend.

I also determined that on my car, 39psi is an optimal hot pressure for the front left tire. This data was gathered with a probe pyrometer. My tire temperatures were even across the face of the left front tire around 155 degrees F after a half of a lap cooldown, checked in the hot pits.

I wish I had more data, but wanted to share what I had.

I will gladly answer any questions on particulars. I just want the BMW community to have all of the information that it can on tire selection, as frequently it's a guessing game based off of hearsay and reviews on autocross tracks.

Level8Drummer

[Jason5driver]

Do the Hankook Rs-3's handle badly in the rain?
And, don't they wear out rather quickly too?

[pbonsalb]

But they are inexpensive.

[Dubbedown]

if price were equal, would you still pick these over the star specs? i'm in the same boat as you, although not an instructor. but i'm looking for tires for hpde but also can be driven on street. long treadlife is an added benefit but clearly not a must given the type of tires i'm considering.

i've heard star specs get a bit greasy after 15 mins or so which is why i'm leaning towards the r-s3's... but i've also read the direzza's last longer and perform better in the wet, and considering these will be used on the street, i see value in that as well.

[Level8drummer]

I think the RS-3's are OK in the rain. They're not the best for hydroplane resistance, but they do have great grip on wet asphault. All you have to do is tone it down about 5-10 mph when there is standing water.

They actually last better than I expected. I have had the same set on my car since christmas, and they're just now dead. I didn't expect them to last through more than 4-5 track events, and they've lasted 2 more than that and they're not corded yet.

If I didn't do track events, I would expect them to last 15-20k miles maybe? I don't slide around much on the street, so they get fairly well preserved. That's the good thing about having a tire this grippy. To slide on the street, I have to do over double the speed limit around curves...which I don't usually do. The car can do clover leaf offramps at 60-65 with these tires and my suspension setup. With a bone stock suspension and a staggered setup, I'm sure you could hold 50-55 with them.

Get a zero toe alignment up front, and 1/16th total toe in in the rear, and they'll last a while. Also, have the tire removed from the wheel, and flopped when the inside tread is half-way gone.

As far as heat resistance, as long as you're not driving like you're in time trials, they do just fine. When I am driving for lap times, my best is always my third lap, and that is the tire's fault (or mine for keeping a little slip angle all of the time on a street tire ;) because they get overheated after that. If you're smooth and driving about 1-2 seconds per lap off of max pace, they will go all day long and not get too hot. It's just when you try to get that last second or 2, and you're at road atlanta in the summer and it's almost 100 degrees that they overheat ;) When I drove at barber in March, the tires didn't overheat at all during 30 minute track sessions.

I don't have as much experience driving on starspecs as I'd like. I had a student with them on a car similar to mine, and he had good grip. They were just fine because he wasn't pushing super hard.

Yes, I would go with the RS-3's over the starspecs. I know they do well and I have had no problems. And heck, they ARE cheaper. Really the pricepoint made my decision. I think the performance differences are probably like splitting hairs. Grassroots motorsports did a comparison between the top max grip street tires, and the hankook took the win...albeit barely.

I don't know about longevity with the direzzas, but if they last 15% longer, the hankooks are still cheaper per mile driven.

Level8Drummer

[scoobyej20]

39psi is an optimal hot pressure for the front left tire

Are you running the same hot pressures in the others?

PS - love the TRM C2 pics in Charleston. I just picked up some black C2s and RS-3s (hence my question).

[mrf]

Let me also echo similar sentiments as the OP about these tires. Fantastic grip, and don't overheat as easily until you really overdrive the car. Here is a chart comparing them to Dunlop DZ101 tires. The RS-3s were about 4 seconds faster over an 80min road course.

Nothing changed between the two graphs except for the tires.


http://www.youtube.com/watch?v=0ObIa8HQA64&t=8m40s&hd=1
Nelson Ledges Road Course in Ohio
https://lh3.googleusercontent.com/-3ZuXbVrNovo/UAthOI6HhhI/AAAAAAAACGw/Mb852Euin-0/s1362/comparo.jpg

[scoobyej20]

Are you attributing 4 seconds solely to tires on a 2 mile track? what does "80min" mean?

[mrf]

Oops, I meant to say 80second lap. And yes, the 4 second difference was solely due to the tires. If anything the difference should've been even greater if the ambient temperature was more similar. You can see the acceleration slopes of the faster lap aren't quite as steep. That's because it was nearly 30F warmer that day.

[Level8drummer]

Are you running the same hot pressures in the others?

PS - love the TRM C2 pics in Charleston. I just picked up some black C2s and RS-3s (hence my question).

Yes...however nowadays I do closer to 41 for tire wear...not sure that it's optimal.

Thanks man, I appreciate it ;)

As far as tires giving you 4 seconds on a road course, that's very common. New RS-3's gave me over 3 seconds over a practically corded set of RS-3's at barber motorsports park.

And the DZ101 is not the star spec, the star spec is much faster. 300 treadwear dz101, 200 treadwear for the starspec (which is a little higher than they should be rated, imo), and 140 treadwear for the RS-3.

Level8Drummer

[EURO M3 CSL]

sorry to bring an old thread back to life. just curious as what u guys usually run for PSI when cold? i know it depend on exterior temperature and track temp and ground temp, but overall.. whats the average tire psi u guys run?