16 Heat Cycles and more to come....

[mcmmotorsports]

Okay, here are my R888's after their 16th heat cycle. Still plenty of grip in them and they are all around 4/32. These were purchased full tread.

 

[JoshC]

Have you tried comparing lap times to a new set? My experience (granted, with a different car) has been a 3 second drop in laptimes and noteable loss in grip after only 6 heat cycles. Changing to a new set regains control and lap times.

[mcmmotorsports]

Have you tried comparing lap times to a new set? My experience (granted, with a different car) has been a 3 second drop in laptimes and noteable loss in grip after only 6 heat cycles. Changing to a new set regains control and lap times.

 

We are gonna try this in 2 weeks at Road Atlanta.

[rlofgren]

i'm on something near 25 heat cycles on my r-888s, puchased unshaved. mine look like yours, but more worn, down to the wear bars. At our last race at thunderhill, i went 2 seconds a lap faster than i had ever gone on ra-1s. Still undecided on the whole tire thing though.

[mcmmotorsports]

At our last race at thunderhill, i went 2 seconds a lap faster than i had ever gone on ra-1s. Still undecided on the whole tire thing though.

 

How can you be undecided?

[944-Spec#94]

i'm on something near 25 heat cycles on my r-888s, puchased unshaved. mine look like yours, but more worn, down to the wear bars. At our last race at thunderhill, i went 2 seconds a lap faster than i had ever gone on ra-1s. Still undecided on the whole tire thing though.

 

 

Well that is good news. I had been getting 24-28 from RA-1's before they lost grip and got slow for me. That was consistant over many sets of tires so maybe we finding the sweet spot on R888s. The plan for 2010 is to be on one tire and if we can get 20+ usefull heat cycles from the R888 it is looking pretty good.

[Big Dog]

Good to hear that someone is getting more that 12 to 15 heat cycles on their 888's.

 

I am not. I am finding that the grip goes away while I still have good tread left. I can go out with what appears to be reasonable tread on tires with 10 to 15 heat cycles and have the grip go away during the session. I find that when I come in, much of the tread that I started with is gone. There is still some tread but it seems that there was lots of wear during the session.

 

This seems to be a new pattern for me and it is connected to higher air temperatures and track temps so that may be part of the issue.

 

Over all, I am not seeing anywhere the kind of wear that Rick and Joe are reporting.

 

Big Dog

[rlofgren]

I am still undecided about the tires since the last thunderhill weekend was just funky. We were all talking about why we were all going so fast. I think everybody there had a personal best time, besting their old times by 2-3 seconds. Weird. I think my new lap record will stand for a while. The r-888s still seem like a mystery to me. I will have to start wearing in my newer set with only 5 heat cycles on them and see how they compare to my almost dead set.

[944-Spec#94]

Here are my 3 sets of R888

 

Old worn set (right) had 14 HC cycles and were dead. No grip, but still some rubber.

 

Middle set is new and the set on the left has 10 as pictured. I ran them 6 more cycles and they are still good I think.

 

 

Here is a shot of them after 16 HC, but sadly marred by a pad picture and by some debris after going off track post a wheel bearing failure.

 

 

 

Now what I want to point out is my first set had much greater inside tire wear. The worn down parts of those tires are the inside shoulders. The newer ones I ran all but the first 3 heat cycles with less negative camber. This really seems to have evened up the wear over the tires. I am stil not sure of the ultimate grip after 16 HC, but I was doin fine on 16th until I had my bearing let go. My next event will a test day in August so I plan to run these for those 4 sessions to see how they hold up. I may even bring them to national, but probalby only as rollers as I don't expect them to be great at 24 HC.

 

Then again may be I can sell the to Rick!

Of coruse if he beats my on my old tires... I am going to feel like crap.

[Tim Comeau]

Ugh! Look at that stack of brand new R-888's! Look at all the wasted grip surface area because of those huge tread grooves (voids). Stupid.

Anyway, what about how long the heat cycles are? 15-20 minutes? 35 mins?

How hard is the car being driven? These are some variables affecting wear and increasing hardness.

[944-Spec#94]

Ugh! Look at that stack of brand new R-888's! Look at all the wasted grip surface area because of those huge tread grooves (voids). Stupid.

Anyway, what about how long the heat cycles are? 15-20 minutes? 35 mins?

How hard is the car being driven? These are some variables affecting wear and increasing hardness.

 

 

Tim,

No sense in complaining about void area in the R888. That is not changing and in the end the only important thing is life. Overall grip is a lesser concern.

 

As for my heat cycles.... Tim you know how I drive... All out every session with most of my sessions at 15-20 mintues or 30 minutes for a race. I don't back down for anything. Bottomline is that it looks very much like the reduced camber is a big deal in making the tires last in my case. That and limiting the sliding. It is a different driving style and set-up, but if all it takes lessen than 1/2 less camber and a little less sliding to make the R888 work to 20+ heat cycles running at the front we are in darn good shape.

 

So far the jury is still out, but as more direct experience comes in things are getting clearer.

[rlofgren]

i suppose my 20+ heat cycles do include some faster and some slower laps. Go only as fast as necessary to win the race. mostly NASA events, 20 minute sessions. i do also finish quali early if i put in my target lap.