Before we could test some tires on our Toyota MR2–we’re looking to maximize performance under some NASA TT regs–we had to do some prep work.
First, we rolled the fenders a tad so we could fit the largest tires possible inside the stock fenders. Read about that step here.
Once we got those 235/40R17 and 255/40R17 tires mounted on …
I've never heat cycled tires before but with the higher cost of the 660s over the previous tire and their habit of delaminating when abused I'm going to start doing that.
The challenge is that it's going to require more tire swaps and tire management than I've done in the past. I've always just stuck a set on, run them till they were worn out and slapped the next set on. Now I'm going to have to either schedule tire scrubbing time at the track or scrub tires during one of the practice sessions on a race weekend.
I suppose I could scrub tires during worker rides.
APEowner said:I've never heat cycled tires before but with the higher cost of the 660s over the previous tire and their habit of delaminating when abused I'm going to start doing that.
The challenge is that it's going to require more tire swaps and tire management than I've done in the past. I've always just stuck a set on, run them till they were worn out and slapped the next set on. Now I'm going to have to either schedule tire scrubbing time at the track or scrub tires during one of the practice sessions on a race weekend.
I suppose I could scrub tires during worker rides.
Admittedly I'm not always great about heat cycling, either. But Andy Hollis has been beating the RT660 heat cycle drum forever and we finally got a chance to put data on his pestering and darned if he wasn't right all along (no surprise there, I suppose).
JG Pasterjak said:APEowner said:I've never heat cycled tires before but with the higher cost of the 660s over the previous tire and their habit of delaminating when abused I'm going to start doing that.
The challenge is that it's going to require more tire swaps and tire management than I've done in the past. I've always just stuck a set on, run them till they were worn out and slapped the next set on. Now I'm going to have to either schedule tire scrubbing time at the track or scrub tires during one of the practice sessions on a race weekend.
I suppose I could scrub tires during worker rides.
Admittedly I'm not always great about heat cycling, either. But Andy Hollis has been beating the RT660 heat cycle drum forever and we finally got a chance to put data on his pestering and darned if he wasn't right all along (no surprise there, I suppose).
I've suspected that they'd benefit from it and I guess it's good to have the data to confirm it but I still don't like it. Reality has a way of being reality whether I like it or not.
I've "heat cycled" my RT660s by just driving on them from home to event.
I can't do that nowadays since I don't have space to swap tires at the apartment, but it's something that was recommended to me.
Heat em up...let 'em cool for 24hrs! Got it! Wait...I paid $375 for this track day. What am I supposed to do for the rest of the sessions? Maybe I'll just run my old set because I always buy new track tires when I already have a perfectly good set.
Ha! This is obviously intended for a more sophisticated, better funded track rat than I! Goals!
V2U_03 said:Heat em up...let 'em cool for 24hrs! Got it! Wait...I paid $375 for this track day. What am I supposed to do for the rest of the sessions? Maybe I'll just run my old set because I always buy new track tires when I already have a perfectly good set.
Ha! This is obviously intended for a more sophisticated, better funded track rat than I! Goals!
Yeah, the struggle is real. Even while we may admittedly have access to some resources that some folks don't, this can even be a complex proposition for us at times. I actually have an email into Falken addressing some of these exact complications, namely, just how hard do you have to stress the tire to produce an adequate heat cycle.
Like, bedding in brake pads is fairly doable on a lightly traveled public road or abandoned parking lot without attracting too much attention or doing anything blatantly illegal. But can the same be said for tire heat cycling? I'd love a real answer to that because even though track time is more accessible and affordable than ever, it's still not exactly easy for some folks driving their tires to the track to just run them for a single break in session then swap to somethign else for the day.
So, yeah. We feel you on this and we're working on answers to improve everyone's expeience.
Trying out my first set of rt660s currently and tried to heat cycle them on some roads near me before my first track day on them. Don't think I was able to get enough heat through them beforehand and lost an impressive amount of tread the first day with some minor delamination occurring when they got hot and started throwing pieces everywhere. Backed it down to about 60%, swapped front to rear, and things improved. If I get another set in the future I'll definitely be heat cycling.
How many questions is the Tire Rack going to get about heat cycling RT660s?
The answer is, yes.
In reply to mhaskins :
That's interesting, I haven't actually properly heat cycled my RT660s but they've held up just fine. When they were new, I drove them straight to an event, ran them, and drove home, and didn't see anything excessive. Do you have pictures of this minor delamination?
Guess what I did yesterday? Went to the track and heat cycled a set of RT660's for an upcoming tire test comparo. :)
In reply to hunter47 :
This is typical of hammering on RT660's w/o a heat cycle...
In reply to slowTA :
Tire Rack will merely refer folks to this tech bulletin on their site: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=66
I had Tire Rack heat cycle the last set of R888R's I bought, I'll have them heat cycle the RT660's I have my eye on for the next Exocet tire. I'm one of those people without access to anything resembling a facility to do this sort of thing myself. Even bedding in brake pads is difficult around here, legally.
So far it looks like our heat cycle by aggressive street driving has worked out. Our first set was heat cycled by just taking them straight to autocross events, but in early season cold weather such that I think we did the first three events without ever getting them fully hot. Something we've noticed that might support shaving as well is that the tire seems to behave a bit different at full tread. Our 200 run old tires have definitely lost a bit of peak grip and pace, but the limit of grip seems to be a bit less harsh and the "over the limit" grip seems to be about the same as the new tires. Which all results in the older tires being a bit easier and more forgiving to drive. Not sure if that's something about the extra tread squirm from the extra depth, or something about the compound breaking in. But those 200 run probably just about heat cycled out tires are still above the wear bars, so new ones could probably have 2/32" shaved off of them and still run out of heat cycles before they cord.
Does a 200 TW tire benefit from heat cycling also? Ready to get on track next week with a set of Toyo R1R's.
te72 said:I had Tire Rack heat cycle the last set of R888R's I bought, I'll have them heat cycle the RT660's I have my eye on for the next Exocet tire. I'm one of those people without access to anything resembling a facility to do this sort of thing myself. Even bedding in brake pads is difficult around here, legally.
This begs the question as to why the manufacturer does not heat cycle them? Could GRM ask this as well?
As of this weekend I'm a heat cycling convert. At least as it applies to the RT660s.
We run the RT660s as the spec tire for spec Miatas at our local track. I scuffed two sets of tires on Friday in preparation for our final event of the year.
I set the pressures at 16 PSI cold and ran laps for 15 minutes. I took about two laps to come up to a speed where I was running as hard as I could with almost no slip angle. That turned out to be laps around 1:40 on a track where race laps are typically around 1:33.5. Tire pressures were about 20 PSI hot when I came off track which is where they seem to be happiest. I didn't get temps. I had intended to but I got distracted. The tires were allowed to cool and sat for about 20 hours.
On Saturday I ran about 4 laps for qualifying, gave 9 laps of worker rides running lap times of around 1:38 and ran two 20 min races. When I rotated the tires on Sunday AM I compared them to those of a fellow racer who had run one 20 min race an a set of un-scuffed tires and mine had only slightly more wear. I could still read the Azenis in the center tread on two of the tires.
On Sunday I ran a 30 min race session and until the clutch started to give up my lap times were pretty consistent with what they'd been on Saturday. I haven't looked closely at the tires but based on a quick glance as I strapped the car down they looked better than I would have expected based on past experience with un-scuffed tires.
My last set of RT-660 was heat-cycled and shaved to 5/32 by Tire Rack. They held up impressively well. I never did any serious tire testing, but the lateral grip was comparable to A052 on concrete, subjectively and according to SoloStorm. The A052 is definitely easier to drive aggressively, though.
dean1484 said:te72 said:I had Tire Rack heat cycle the last set of R888R's I bought, I'll have them heat cycle the RT660's I have my eye on for the next Exocet tire. I'm one of those people without access to anything resembling a facility to do this sort of thing myself. Even bedding in brake pads is difficult around here, legally.
This begs the question as to why the manufacturer does not heat cycle them? Could GRM ask this as well?
I think I know the answer, but lemme ask.
APEowner said:I set the pressures at 16 PSI cold and ran laps for 15 minutes. I took about two laps to come up to a speed where I was running as hard as I could with almost no slip angle. That turned out to be laps around 1:40 on a track where race laps are typically around 1:33.5. Tire pressures were about 20 PSI hot when I came off track which is where they seem to be happiest.
What size tire and wheel do you run in that spec class? I'm surprised at how low your optimal tire pressure is, but I don't have any experience with RT660's yet.
Bigben said:APEowner said:I set the pressures at 16 PSI cold and ran laps for 15 minutes. I took about two laps to come up to a speed where I was running as hard as I could with almost no slip angle. That turned out to be laps around 1:40 on a track where race laps are typically around 1:33.5. Tire pressures were about 20 PSI hot when I came off track which is where they seem to be happiest.
What size tire and wheel do you run in that spec class? I'm surprised at how low your optimal tire pressure is, but I don't have any experience with RT660's yet.
The tires are 205/50R15 on 7" wide wheels. I too am surprised at how low the optimal pressure is. I always ran the RT615s at 30 PSI hot but the 660s really like the lower pressure. The temps are great across the tread, just the right amount of the shoulder is being used, the wear nicely with 3.5 degrees of front camber and the have a ton of grip. At least once the pressures come up. As one might expect they're a little squirmy with the 17 PSI left side and 16 PSI right that I have to start them at until the pressures come up.
Falken has recommended via email that we make sure the Rt660 is 35psi hot for track work, which caused delamination in 2 sessions on Barber.
This was a set of 245/40r15 on 15x10 mounted to my friend's 140hp miata.
On another set of 225/45r15 wrapped around 15x9 on my 140hp miata, I have been shooting for 28-30psi hot and have had no issues. All the tires I am talking about were heat cycled and stored properly.
Falken knows about the problem and is giving out advice that doesn't work for all people. Besides, if the center of the tire is delaminating, how would more pressure solve that problem?
dean1484 said:te72 said:I had Tire Rack heat cycle the last set of R888R's I bought, I'll have them heat cycle the RT660's I have my eye on for the next Exocet tire. I'm one of those people without access to anything resembling a facility to do this sort of thing myself. Even bedding in brake pads is difficult around here, legally.
This begs the question as to why the manufacturer does not heat cycle them? Could GRM ask this as well?
Respectfully, Dean
From a friend in the tire business who knows a lot about the industry.
My question: Why don't tire companies heat cycle their own tires?
Their answer: It's just such a specialty process on a low-volume model that it's nearly impossible to justify at the manufacturing level.
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