Bigger is better

[altiain]

I'm getting the car ready for MSR tomorrow. On the left, a 245/40-18 street tire, mounted on a stock 8" wide wheel. Pretty decent footprint, right?

On the right, a 255/40-17 R888, mounted on a 9" wide wheel.

I'm looking forward to tomorrow!

[Nails]

Niiiice! Goodwin said the R888's run wide for the size.

[MadMerv]

Now that it's over, what did you think of the R888's? What tire pressure worked, if any? We found the tires go away very quickly at TWS a couple of weeks ago. Had forty SM's on them and no one was happy....including Jason Saini.

[altiain]

Yeah, they definitely get greasy faster than the RA1s did. The front right tire took a lot of abuse running CCW. My fastest times typically came about 3-4 laps into a session, then they would go up by .5-.75 seconds and stabilize.

That said, they are a little grippier than the RA1s. On the R888s I can take Ricochet and Tombstone flat out, while on the RA1s I would have to feather the throttle a bit.

I'm curious to see how well they hold up over the long term. I was talking with Bob Neff at MSR on Saturday and he said he got 40-50 sessions out of the R888s on his C5 Z06, but I'm not sure they're going to hold up that well on the RX-8.

I borrowed ken o's Racelogic box for a couple of sessions and ran a best of 1:27.6. I think there is a high 1:25 out there with my car in it's current configuration if I ran with a little less margin for error and work on my entry into Rattlesnake.

[MadMerv]

Qualifing for the Saturday race at TWS had the first sixteen cars all with their fastest lap in lap one or two. Sunday was a bit better with a few in the third and fourth laps. They definitely have more initial grip, but go awy much quicker.

Don't know who Bob Neff is, but I can't imagine forty to fifty sessions on a set. I've been hearing two to three races on a Spec Miata and they're gone. No one has yet to figure out optimum tire pressures. Seems that bigger heavier cars are running high thirties to mid-forties COLD! Doesn't make sense on a Miata. Most were starting 32/31 cold at TWS. Tire temps and pressures indicated to us that we were too high, so we started dropping ours. We ended up 29/27 and were one of only a few that were actually getting quicker, plus, they would go 4-5 laps longer before getting greasy. We're gonna do some testing at TMS next month starting with one set at 25 and another at 40 and go from there........ Another reason we went down on pressure is the side walls are much stiffer than the RA1's.

[altiain]

I started with cold temps of 36, which is a couple of psi lower than I ran with the RA1s.

How many races would an SM typically get on a set of RA1s?

[MadMerv]

Twice as many....

[mk2tmr2]

Niiiice! Goodwin said the R888's run wide for the size.

I'd say! That's a heck of a lot more than a 10mm difference.

[altiain]

I'd say! That's a heck of a lot more than a 10mm difference.

Keep in mind that they're also mounted on an 1" wider wheel in the above pic.

Still, I was talking to a couple of American Iron drivers over the weekend, and they said that the 255/40-17 R888 is within 1/16" as wide as a 275/40-17 RA1 when both are mounted on a 9" wheel.

[mk2tmr2]

How does the OD compare to other wheels of the same size? Are they comparably wider but the same height?

I wonder how they'd work in 245/45-16 for me :)

[Kestrel]

All great information, as at some point very soon, I'm going to have to get a second set of wheels and some race rubber for the Cayman. I was looking at R888s, so I'm interested in all these "reviews" of there performance and durability.

[MadMerv]

The Spec Miata size (205/50-15) are also that much wider at the tread.......

[goofygrin]

I'm looking at getting a set of these to play with on the track.

What's your feeling on how they'd hold up to a heavy car's abuse?

[altiain]

I think you might be better off with a set of shaved RA1s, honestly. These got greasy a lot quicker on my car than the Ra1s did, and my car is 600 pounds lighter than yours and better balanced.

[Nails]

Yea I rode with altiain for a full session last Saturday and was quite impressed with the grip he had. However, in only a 20 minute session, on a ~70 degree ambient temp, he was starting to slip a bit in last 3 laps. Seems like an awful short window for an r-comp but I have no personal experience with them.

[MadMerv]

Ditto.....stick with the RA-1's.....

[altiain]

Yeay, they are stickier than the RA1s. According to the data trace, peak lateral grip was 1.30-1.35 Gs, and peak braking grip was 1.15-1.20 Gs w/o engaging the ABS (I need to learn to brake harder. ). Still, I'll have to see how quickly they wear - and how they handle the summer heat - before I would recommend them to anyone.

BTW, thanks again to ken o for letting me borrow his waffle maker (aka Racelogic VBox Mini) so that I could get some lap times and data. I appreciate it!

[ken o]

No problem. The Mini on street tires want not going to pull wicked times. I will send you the file from the 911 on NT01s. The worked great on the 3300lb 911 and never got greasy. Has anyone tried the NT01 on other cars?

[SirHustlerEsq]

I wish I could find some really wide 205's or 225 for my 15x8 street tires. I like to run all-seasons on the street because I can't seem to not spin the tires in 3rd gear...so I should run all-seasons.