tiger 6

Ran a set of Toyo R888's on my RS for the first time a couple of weeks ago at VIR. Set the pressures at 32 psi cold to get to 37-38 psi hot. I have -2.6 camber on the front and -2.2 0n the back. Front sway bar is full stiff and rear is full soft.
When I changed the tires back to my street tires and rims, I noticed the R888's in the rear had a good bit of "chunking" on the insides of the tire and a wear strip of ~ 2 in. on the outside edges. The front tires had a similar appearance with slightly less "chunking" on the inside and ~ 1 in. of wear on the outside.
Is this a normal wear pattern for these tires? I have 5x25 minute sessions on the tires and drive to and from the track[220 miles round trip] with them set at the recommended street pressures.
Thanks.

tiger 6

Correction-sway bars are full soft in front and full stiff in rear. Not enough coffee yet!

Bob Rouleau

CHeck the Toyoa website. They have revised care and feeding instructions for the R888. Among other things HOT pressure should be in the 32-35 lbs range. Think they also mentioned less camber too.

997gt3north

- if you start at 32, are you sure you are only getting to 37-38?
- if you taking it easy and the sessions aren't quite 25 minutes i can see it but i would think that your actual on track temps would look more like 40 to 42
- this may or may not be the issue, but i have had a few different tire guages and almost none show the same temps - the stock free one is really bad so don't use it

- if driven hard (sliding) the r888s do / can chunk around the edges of the rain channels if that is what you are talking about (don't worry)
- the wear marking (discoloration / change of rubber consistency) that you can see on the outside edge after a heat cycle is normal and is clearly a chemical issue of parts of the tire that are getting hot enough versus the parts that are not
- if you are getting chunking on the inside edges - possible explanations:
1) tire temps too high and the middle and outsides of the tire are not getting enough work
2) at your speed or your speed on that day (weather?) you needed less camber
3) your LSD is shot and your inside wheel is lifting and the tire is spinning causing lots of wear on the inside edge (you won't be the first but check the other explanations first)

My first day on the r888s i was lucky as i was at an open trackday at Watkins Glen and I was able to go out and do a few 15 minute sessions to get the slimy crap out of the tires (they were crazy slippery until i did) - maybe it is possible that the tires got a little to abused in their first heat cycle?

I run my hot front at 33 and hot rear at 36 and I like them at that level

good luck

paul

DanH

We had Toyo reps come out to UK trackdays to work out some settings for these tyres on the 6 RS. They recommend pressures of 36/38 F/R. If you run lower, especially with camber you'd think ok from MPSC etc the inside shoulders wear very quickly and can delaminate/fail. Probably down to the stiff side walls.

I have run a few sets of these as I was trying to save cash on MPSC (2x the price in the UK), but having tried a set of MPSC I don't see myself ever going back. The toyos overheat too quick, don't ride well, don't like camber and make a terrible background roar on the motorway. I guess thats what comes when you use a tyre designed around Japanese saloon cars, rather than are **** engined pendulums!

Bob Rouleau

I repeat, Toyo has issued an update on the R 888 saying hot pressures should be 32 to 35 lbs HOT. Here is the press release from Oct 6 2008.

October 6, 2008
MAXIMIZING PROXES R888 PERFORMANCE
RICHMOND, BRITISH COLUMBIA -- The PROXES R888 is the most extreme R-compound tire in Toyo Canada’s product offering, designed with several advancements in tread pattern design and construction. In order to realize these performance improvements, the car setup needs to cater specifically to the PROXES R888 and therefore varies from PROXES RA1 recommendations. The tread of the PROXES R888 is significantly wider than the PROXES RA1 and requires less
negative camber to achieve equal slip angle and higher cornering force values. Due to the wider tread, using a lower camber setting will result in a more evenly dispersed contact patch thus creating more consistent hot temperatures across the tire and improving overall performance.
The correct initial air pressure is also critical to achieve an optimum contact patch shape. Here are examples to be used as a guideline only, of successful cold and hot temperatures across three different vehicles:
TOYOTA VITZ (SCP10): Cold 29-32psi (200-220kPa) / Hot 32-35psi (220-240kPa)
HONDA CIVIC (EK9): Cold 26-29psi (180-200kPa) / Hot 32-35psi (220-240kPa)
MITSUBISHI LANCER Evolution (CT9A): Cold 26-29psi (180-200kPa) / Hot 32-38psi (220-260kPa)
A pyrometer is the best way to confirm that the tire is reaching its optimum operating temperature while also providing an accurate determination of temperatures across the tread. Maximum grip levels can be achieved when the optimum temperature levels are evenly dispersed throughout the tread.

fc-racer

They use the Toyo R888's as the spec tire in the Speed World Challenge series and the GT3 drivers there seem to do well on them. No matter what tire you use, you need to spend some time dialing the car in. With MPSC's, it's much easier since the factory did the work for you.

todinlaw

Has anyone taken the time to use a pyrometer with the triple 8 and see what tire pressure and camber work well on a 3. Care to share?

fc-racer

I ran a pyrometer on my R888's, but am not sure what the ideal temp range is. I was getting 190F on the outside edge up front and a little less inside, so I dialed in more negative camber. For the rear, I was getting 200F on the inside and so dialed in less negative camber. I would imagine the temps would be a bit higher on-track vs. in the pits.

This is where I ended up for camber:

-2d15m front
-2d15m rear

I haven't had the chance to temp check the new setup, however I think a good driver that is really pushing hard would end up at -2d30m and -2d0m front and rear respectively. I'm still a bit tentative around my local track to fully exploit a more neutral/rear-biased setup. For reference, I turn 1:38.5's at Mosport on R888's.

Bob Rouleau

I ran my r888 on a GT3RS with neg 2.5F neg 2.4 rear. Hot pressure 33F 34R. Temps (infrared so not perfectly accurate were 170 175 179 out to in on the rear. Worked pretty well but I still like Hoosieers better.

C.J. Ichiban

chunking tires is almost always a result of PSI being too high.

todinlaw

I am assuming you are running 19 inch wheels? The GT3 suspension is relatively stiff, Were you running the suspension button of Soft or stiff? I am not sure at this point that you would need significantly more negative camber at I do not think the the 3 suspension is subject to much rollover. I am still experimenting my self, but running f -2.2 rear -2.1 and look to be even across the surface of the tire. Always curious to see what others are experiencing. with setups.

C.J. Ichiban

my opinion of the 3/RS setup is that it's much too soft and rolls too much...that's why I put solid bushings in...the front spring rates are painfully spongy at high G tracks like infineon.

fc-racer

I'm running the 255/315 18" setup. Car setup is such a difficult thing to do over the internet. I've seen drivers pay to have their car setup by a pro, who is able to turn amazing times in the car, and end up with a car they find undriveable.

Some general car setup thoughts:

It's also been my experience that driving capability, driving style and the track itself plays a huge role in car setup. Chunking is almost always because the driver is entering or exiting the corners too fast for the front tires. Even a badly setup car should not chunk tires if you're driving within the tires' limits.

All the advice given can only give you a rough idea of where you should be; from there, it's important to tweak the car to your liking and to your budget. I'd also recommend trying setups that you don't think you'll like.

As an example, I have many racing friends that prefer cars that oversteer, yet when you stick them into a car that understeers slightly, they're faster because they can carry more corner entry speed with confidence. Oddly, they go back to their own car and continue with the oversteer setup because they are too manly to admit they're faster in a confidence inspiring car...

DanH

lol & I repeat those settings were developed around jap saloons (have a look at the cars you listed!) and Toyo reps in the UK do not support them on the 6 GT3 on which they were testing.

I have no problem with people doing as they please, but make sure you check the inside shoulders regularly on the rears. I had a blowout on one returning from the ring as the inside edge went. So glad it didn't happen at the ring! Anyway I put that down to the stiff sidewalls and me not checking them enough.

My opinion and that of cup racers who drove my car with them on was that they don't suit the car anything like as well as the MPSC.

You pays your money and makes your choice. Just don't see the point in these when you could run hoosiers.