96GS#007

I see a lot of discussion about the R888s so I thought I'd add to the "database".

Car Info....
- 2013 Grand Sport coupe, 6 speed, dry-sump
- DRM Bilstein shocks but otherwise stock suspension and ride height
- -1.6* Camber (F) / -1.1* Camber (R)
- 0 toe (F) / slight toe-in rear (sorry, don't have my printout in front of me)

Track & conditions
- Willow Springs ("Big Willow")
- low 70s in the morning, 105* in the afternoon
- My transponder didn't work in the morning. Best afternoon lap was a 1.39

I experimented with a variety of hot pressures.
- <35psi hot showed excessive roll-over and uneven temps...hot on edges (especially outside edges), cooler in the middle
- 35-38 psi showed even temperatures. Tire provided good feedback upon corner entry and even at 90*+ outside air temp maintained grip. The car felt most comfortable at these inflation levels.
- >38 psi was extremely greasy. Tire temp was high in the center of the tire. Lots of push upon entry and very easy to hang the tail out with a touch of throttle. Frankly it was not confidence inspiring.

Based on wear, it looks like I could use another .5* of negative camber, front and rear.

The tires do whine, although not as bad as some. Front straight speeds were low-mid 130s.

All in all, pretty happy with their performance. Before my next track day, I'll flip them on the rims to even out the wear and add a little more camber.

FWIW

spdislife

Been using them the last 2 seasons and I like them. I'll agree on the tire pressures. Mid 30s seems to work best. Decent wear too. 04Z

mikeCsix

FWIW ...

Coming from you Jim, its a lot! Thanks for posting.

What brand of heat measuring device are you using?

I had some interesting wear patterns on my GY RF's I suspect are due to incorrect pressure and not quite enough camber given the pressures you ran on the 888's. I kept mine down around 30 and I suspect I was getting some shoulder roll or something. The center tread of the tire wore more than the outer and the outer tread wore more than the inner, both front and rear. Front camber is set for -1.2 and the rear is -0.7, no toe in front and +0.1 in rear. I think the rear should be toe-in by the same amount. Other than that, the tires seem to be wearing just fine.

How do you like the DRM Bilstein's? I have a set coming in sometime this month.

I checked out Willows online, only 9 turns. The transmission stay cool?

12zo

I also ran my 888's at 35psi. The wear looks good.
I have -3f and -1.7r camber.
Started the tires at 27psi cold and went from tere to get 35psi.
Stock suspension aside from alignment.

I was just going to swap them left to right. Not running in the wet so I don't hear of any issues running them "backwards".

96GS#007

Thanks Mike!

I ran the OEM GY runflats for a bit just to use them up (replaced at 15k or so miles with MPSS). The GYs were not a confidence inspiring tire, although I've been using R-compounds for years so I'm sure that affects my perception significantly. FWIW, more wear in the center suggests over-inflation. I had the best luck with the GYs at ~28-30psi Hot.

Love the DRM Bilsteins. Everything you read about them....true. Great ride on the street. On the track, the back-end feels much more planted. Overall control is much more positive during transitions.

Transmission....no issues with the 6 speed manual. I have Redline MTL in it. Is yours an auto?

mikeCsix

Hi Jim, thanks for the feedback on the DRM's. The rear had been feeling a little light and twitchy though didn't mind the street ride. Have been thinking about changing the rear spring for a Z06 version but only want to make one change at a time.

Transmissions, I have the A6 and need some additional cooling. From what I've learned so far, the differential gets hot quickly, I performed a differential fluid change a month ago and was disappointed with how dark it was, this was about 14k miles. Next project is a diff cooler, I think it will help the transmission temps.

It looks like Willow has 9 turns, that may help keep the diff cooler, and I think the M6's already have a differential cooler/ heat exchanger using transmission fluid as the cooling "medium".

I'm also going to the MPSS's when the GY's are done.

Sounds like you are having a great time in LA, do you get back up here often?

von zoom

I ran them and had very good results - no complaints. From the beginning, I started 315/30/18 - 335/30/18 cold with 27 front, 28 rear, looking for mid 30s hot. Factory camber settings. Running Hoosiers now.
vz

hungryhippo

Thanks for the input. I have a set waiting to go on when my 555r2's are done.

LFZ

I like mine..and they do love camber. Great tyre to get you to and from the track.

96GS#007

The DRM shocks will settle the rear end down for you. I think you'll be pleased.

Mine is a dry sump car, so it has the fluid to air coolers, for the diff and the transmission. Different fluids in them so two coolers.

I make it up to the SEA area about once every 4 weeks, sometimes 6. I have staff located there that I meet with.

You had asked about tire temp measurement....I'm just using a laser temp gun. A probe is the right way to get the temps, but I can at least see trends and relationships across the tire with the laser. One of these days I need to get around to buying a temp probe.

96GS#007

It's been discussed before with other tires, but I thought I'd show pics of how the R888s "creep" on the rim. The pics are of the fronts after the first session of the day. Low 70s outside air temp, 35psi hot. The tires continued to move, regardless of pressures. By the end of the day they almost lined up again The OEM rims are basically new (18 miles on them when I had the tires mounted), the tires were mounted at a place does a lot of track car work, and they were balanced on a Hunter Roadforce machine....





The rears also moved, although about 25% as much.

Gratuitous selfie .....

mikeCsix

Awesome pic's Jim!

I had no idea tires moved so much on the rims, how do they stay balanced?

Sent you a pm.

Mike

troyguitar

Usually you just balance the wheel by itself and ignore the tire since it moves.

808EB03Z06

Based on the posting here, would the same rules apply to these for pressures in auto-x as on a road course?

96GS#007

In general I'll say yes. However, IMO it's unlikely that an auto-x will get them hot enough to work. It takes 1-2 laps on a road course before they really start to stick. Haven't seen an auto-x that has that sort of "run time". I'd look more towards a Hoosier A6

NOSLO6

I ran these tires for track days for a couple of years (and really liked them).

Did two autocrosses with them and, as the above quote suggests, they didn't come close to coming up to temp, even on summer days with hot pavement. Not the tires you'd want for auto-x if you're aiming to be competitive.

fmcokc

I ran them last weekend for the first time. 2003 Z06 with Pfadt coilovers, bushings sways, bumpsteer, -2.4 F, -1.7 R. Found them to be squirmy at full tread depth. Got real greasy feeling when higher than 38 psi. Backed them down to ~35 psi and was better but still not what I would call great.

To be honest, the car is new to me and needs to be tuned some more. (Sways and shocks adjusted some more)

skxf430

All tires will creep especially R compounds being stickier.

Next time try having your tires mounted with hair spray which will help prevent creep. Also, you can have your wheels bead blasted which will help too.