New tire proposal
08-21-2013, 09:06 AM
#46
Perfect Angel
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Thread Starter
Paul clued me into the discussion here. I've been gathering a lot of data on these tires over the last year relative to the RA-1 as NASA 944 Spec National director (and a driver). I also run Hoosiers, and the BFG R1 in enduros (separate contingency), so I have some back to back data with those tires as well.
The first production run of RR's in our 225/50/15 size had delamination issues. The specified rotation helped, but did not eliminate this. No catastrophic failures, but lots of splits. The second run (week 50+) tires have been better.
Driving impressions:
Very friendly and easy to drive tire at the limit. We would drop 1.5-2seconds per lap within 2-3 laps, of bolting them on - very easy to drive fast quicklly. Every lap record in 944 Spec Midwest was decimated this year. The RR is a much easier tire to drive than the R1 [is that tire smoke back there - crap, another flat spot!]. It tolerates more slip angle without chattering. Not quite as heroic as a fresh Hoosier, but much more consistent through it's life.
Setup:
We found the RR likes a little more camber, and similar to a hair less pressure than the RA-1. They will be fast just bolting them on to your RA-1 setup, but they won't last as long without some extra camber (at least).
These tires are more fussy to a good setup than the RA-1. Guys who ran lower camber, and less roll stiffness would cord the outside edge fairly quickly, sometimes within 8 heat cycles. The RA-1 is more forgiving of less than ideal setups.
Longetivity:
With proper setup, every bit as good as a 4/32nd's shaved RA-1. Remember the treadwear ratings are based on full tread depth, not a shaved tire. The three National Championship podium drivers in our region (i.e fast, consistent, and work the tires hard) get around 21 heat cycles (range 18-24). For us, this is at least equal to what we seeing out of RA-1's. You results may vary, but with the right setup, should be similar to what you got on RA-1's
We have run 4 back to back trials of tires with 17-18 heat cycles, and new sticker RR's. To our surprise, in every case (at the tracks we run), the old tires were equal or faster. They may have taken slightly longer to come in than stickers (more tire goobers?), but ultimate lap times usually favored (and were never slower) on the old tires. Again, the drivers I'm referencing are very consistent. While this data was a surprise to us, it seems solid.
After a rocky start with delamination, and setup issues, I like the RR. It is a very fun tire to drive, and in our experience, highly consistent, which is key for a spec tire. I also like that I can run it competitively in open-tire enduros (especially now that Toyo has expanded it's contingency to enduros). I liked the RA-1, too, though, and it's a known quantity for you guys.
The first production run of RR's in our 225/50/15 size had delamination issues. The specified rotation helped, but did not eliminate this. No catastrophic failures, but lots of splits. The second run (week 50+) tires have been better.
Driving impressions:
Very friendly and easy to drive tire at the limit. We would drop 1.5-2seconds per lap within 2-3 laps, of bolting them on - very easy to drive fast quicklly. Every lap record in 944 Spec Midwest was decimated this year. The RR is a much easier tire to drive than the R1 [is that tire smoke back there - crap, another flat spot!]. It tolerates more slip angle without chattering. Not quite as heroic as a fresh Hoosier, but much more consistent through it's life.
Setup:
We found the RR likes a little more camber, and similar to a hair less pressure than the RA-1. They will be fast just bolting them on to your RA-1 setup, but they won't last as long without some extra camber (at least).
These tires are more fussy to a good setup than the RA-1. Guys who ran lower camber, and less roll stiffness would cord the outside edge fairly quickly, sometimes within 8 heat cycles. The RA-1 is more forgiving of less than ideal setups.
Longetivity:
With proper setup, every bit as good as a 4/32nd's shaved RA-1. Remember the treadwear ratings are based on full tread depth, not a shaved tire. The three National Championship podium drivers in our region (i.e fast, consistent, and work the tires hard) get around 21 heat cycles (range 18-24). For us, this is at least equal to what we seeing out of RA-1's. You results may vary, but with the right setup, should be similar to what you got on RA-1's
We have run 4 back to back trials of tires with 17-18 heat cycles, and new sticker RR's. To our surprise, in every case (at the tracks we run), the old tires were equal or faster. They may have taken slightly longer to come in than stickers (more tire goobers?), but ultimate lap times usually favored (and were never slower) on the old tires. Again, the drivers I'm referencing are very consistent. While this data was a surprise to us, it seems solid.
After a rocky start with delamination, and setup issues, I like the RR. It is a very fun tire to drive, and in our experience, highly consistent, which is key for a spec tire. I also like that I can run it competitively in open-tire enduros (especially now that Toyo has expanded it's contingency to enduros). I liked the RA-1, too, though, and it's a known quantity for you guys.
The only other concern I have is how long will they last when driven by someone as fast as me?
08-21-2013, 10:08 AM
#47
Rennlist Member
08-21-2013, 10:40 PM
#53
Rennlist Member
08-22-2013, 12:39 AM
#54
Rennlist Member
Ok then let's present what we really have (which BTW is a long way from being "Just an RA1 which is molded with less tread" - sorry Paul really not trying to pick a fight just trying to understand what's going on here)
From what we are hearing, we have is a tire that:
-is faster than our current by somewhere between .5 and 2 sec.
-will cost about the same as our current net/net.
-may be more consistent (if that was ever an RA1 issue)
Against this tire we have that it:
-cannot be used as a rain tire and will require the use of a second spec tire.
-may have less life than the current (similar at best)
-can't be swapped side to side
-has less real time data to assess it by than the RA1
-may require use of GT3 bottom arms at the rear (if you arent already using them) to achieve extra camber that MAY be needed.
I know what my choice would be (assuming I Have a choice and the RA1 is not discontinued).
From what we are hearing, we have is a tire that:
-is faster than our current by somewhere between .5 and 2 sec.
-will cost about the same as our current net/net.
-may be more consistent (if that was ever an RA1 issue)
Against this tire we have that it:
-cannot be used as a rain tire and will require the use of a second spec tire.
-may have less life than the current (similar at best)
-can't be swapped side to side
-has less real time data to assess it by than the RA1
-may require use of GT3 bottom arms at the rear (if you arent already using them) to achieve extra camber that MAY be needed.
I know what my choice would be (assuming I Have a choice and the RA1 is not discontinued).
08-23-2013, 01:13 AM
#56
Based on what I've read here and elsewhere I'm willing to try out the RR. Shaving and managing the sweet spot on RA-1 can get tedious, and we heat cycle them out before seeing cords. Most guys in front are shaving them deep, minimize tread depth and heat which is constant in TX, except perhaps one race. Eliminate more variables, what depth, square or rounded shave shape, who shaves the best or screws up the occasional tire (same issue as Paul).
If the RR is a bolt it on and drive proposition then I'm for it, don't care if it's slower or faster. Although faster will give the E cars more SPBs to manage.
Does the RR grain or cold tear like the RA-1?
If the RR is a bolt it on and drive proposition then I'm for it, don't care if it's slower or faster. Although faster will give the E cars more SPBs to manage.
Does the RR grain or cold tear like the RA-1?
08-26-2013, 02:42 PM
#57
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Just got back from a VERY Hot weekend at Calspeedway (Fontucky ambient temps at 102 with high humidity). Ran the RR in the sprint race and the 1 hour and 5 min. enduro with only 45 minute break in between each race. With the exception of a little greasy feeling about 25% of the way in, they were pretty consistent and no graining issues.
