Tires for track?
#46
08-11-2010, 11:35 AM
I have experience with the R80/R100's on much heavier AWD cars, with more hp and much heavier than the GT3/GT2. I havent tired them on the GT3 yet, but with a 3000lb car, 2wd, and much less power I am speculating the results would be comparable with respect to wear.
As an example, the set of R100's I used this past weekend on the GT-R (3850lbs with driver 550whp) had 13 HC's on them, and then I put 4 more on them this weekend. Total of 17 HC's and the tires performed very well. I'd say about 85% of their new strength. Ran a 1:29.5 at Road Atlanta in 115F track temps. No cords yet.
In terms of how you drive the car, I am referring to how much sliding and aggression you put into your laps. You can have two drivers with the same lap time, and same car, but one driver can be harder on their tires, so if the car moves around alot and your hands are busy, you are going to go through tires faster than the guy that's more calm and smooth behind the wheel.
As an example, the set of R100's I used this past weekend on the GT-R (3850lbs with driver 550whp) had 13 HC's on them, and then I put 4 more on them this weekend. Total of 17 HC's and the tires performed very well. I'd say about 85% of their new strength. Ran a 1:29.5 at Road Atlanta in 115F track temps. No cords yet.
In terms of how you drive the car, I am referring to how much sliding and aggression you put into your laps. You can have two drivers with the same lap time, and same car, but one driver can be harder on their tires, so if the car moves around alot and your hands are busy, you are going to go through tires faster than the guy that's more calm and smooth behind the wheel.
Well, I have been running R6s for years, so I guess it's time that I just try out the R100s myself and submit my data points. I can nurse a set of R6s up to 20+ HCs, so hopefully, I will see 20 with the R100s as well.
-td
Last edited by himself; 08-11-2010 at 11:38 AM.
#47
08-11-2010, 10:17 PM
I'm getting low 600 miles to 800+ miles from Corsa's, 28 to 34 HC's.
I'm looking for a reason to try something else but I usually manage to get them for about 275 each and that's a pretty good deal (for Corsa's anyway.)
#48
08-12-2010, 11:45 AM
Could be 1 mile or 50.
-td
#49
08-12-2010, 12:30 PM
Agreed. The reason many of us focus on HC's is because we HC the tires out before actually wearing the tread down to an unsafe level.
#50
08-12-2010, 12:53 PM
Interesting. I have been getting inconsistent feedback regarding r80/100 longevity. Some of the hardcore folks I communicate with are reporting cording R80/100s well before 15 HC. Perhaps it is about setup and/or driving style.
And when you say "depending on how you drive them" - what does that mean? Is there any other way but flat out?
To get some data points, what car are you driving, its weight, TC on/off, and what are your alignment settings? Spring rates? Are you solid everywhere? What temps are you getting across the R80/100s? Are you driving them the same way as R6s? Or are you using less slip angle?
Sorry for the 20 questions, but I want to figure out why some folks get R80/100 to "last," and others are seeing cording rather quickly.
Cheers,
-td
And when you say "depending on how you drive them" - what does that mean? Is there any other way but flat out?
To get some data points, what car are you driving, its weight, TC on/off, and what are your alignment settings? Spring rates? Are you solid everywhere? What temps are you getting across the R80/100s? Are you driving them the same way as R6s? Or are you using less slip angle?
Sorry for the 20 questions, but I want to figure out why some folks get R80/100 to "last," and others are seeing cording rather quickly.
Cheers,
-td
If guys are cording them that fast, especially if it's only a DE (race conditions are far different) they need to break out the pyrometer and check the tire temps and wear. And sometimes it could just plain be the track type, some tracks just eat tires for breakfast if the surface is rough.
#51
08-12-2010, 05:20 PM
YMMV
#52
08-12-2010, 08:06 PM
And the wear from 1 HC, regardless of how many miles it is, won't reduce the max number of HCs available as these tires typically heat cycle out long before they run out of rubber. If you are cording early, that's setup, not tire. The only variable here is if you are running multiple enduros on 1 set of tires. But with a street GT3, we aren't
YMMV.
-td
#53
08-12-2010, 08:33 PM
Nah, I disagree. You only get a certain number of HCs out a set of track tires before their performance drops off. I get around 20 out of Hoosier R6s. It doesn't matter how long the sessions are or how long the track is. I get around 20.
And the wear from 1 HC, regardless of how many miles it is, won't reduce the max number of HCs available as these tires typically heat cycle out long before they run out of rubber. If you are cording early, that's setup, not tire. The only variable here is if you are running multiple enduros on 1 set of tires. But with a street GT3, we aren't
YMMV.
-td
And the wear from 1 HC, regardless of how many miles it is, won't reduce the max number of HCs available as these tires typically heat cycle out long before they run out of rubber. If you are cording early, that's setup, not tire. The only variable here is if you are running multiple enduros on 1 set of tires. But with a street GT3, we aren't
YMMV.
-td
I will say that I don't think if your session gets black flagged after two laps, the tires get the same wear as they will after a 30 minute session. Yes the Hoosiers run out of grip long before tread, but that's a bit over the top.
I know because I've done lots of Time Trials, and being in time trials in a high hp car you will catch back markers after 3 laps (sometimes 2). Then off the track it is. I get lots of heat cycles out of tires due to driving like this. There will be some grip degredation due to cycling, but not nearly as much as going for far longer.
#54
08-12-2010, 08:50 PM
It's somewhere in between. If you get a set of Hoosiers from a SCCA T1 racer (let's say R6 or A6) after they ran qualifying and a race on one set, those tires will be shot and good for practice only.
I know because I've done lots of Time Trials, and being in time trials in a high hp car you will catch back markers after 3 laps (sometimes 2). Then off the track it is. I get lots of heat cycles out of tires due to driving like this. There will be some grip degredation due to cycling, but not nearly as much as going for far longer.
I know because I've done lots of Time Trials, and being in time trials in a high hp car you will catch back markers after 3 laps (sometimes 2). Then off the track it is. I get lots of heat cycles out of tires due to driving like this. There will be some grip degredation due to cycling, but not nearly as much as going for far longer.
If you can run yours way past 20, good on you, but I've been running these things for years and they do HC out....
-td
#55
08-12-2010, 09:39 PM
You missed my point, which is that you cannot call an enduro hc the same as a de session hc, and by the same token a full de session de session to a two lapper. If you are driving hard enough it doesn't take more than 2 laps or so to get any dot up to temp. But I can bet you ill get a whole lot more hc than a guy who's racing 20 + lap races. And its ALWAYS about grip.
#56
08-13-2010, 08:39 AM
You missed my point, which is that you cannot call an enduro hc the same as a de session hc, and by the same token a full de session de session to a two lapper. If you are driving hard enough it doesn't take more than 2 laps or so to get any dot up to temp. But I can bet you ill get a whole lot more hc than a guy who's racing 20 + lap races. And its ALWAYS about grip.
I'm sure you drive flat out.
-td
#57
08-13-2010, 09:34 AM
Heavychevy...I know you...but refresh my memory again?
I think most of the group in this thread is referring to hc's in a 20 min hpde session at a brisk pace. When racing or doing extend lapping, the number of hc's before a tire goes off is more fluid. I let the tire tell me when she's had enough regardless of HC's.
I think most of the group in this thread is referring to hc's in a 20 min hpde session at a brisk pace. When racing or doing extend lapping, the number of hc's before a tire goes off is more fluid. I let the tire tell me when she's had enough regardless of HC's.
#58
08-13-2010, 11:52 AM
Heavychevy...I know you...but refresh my memory again?
I think most of the group in this thread is referring to hc's in a 20 min hpde session at a brisk pace. When racing or doing extend lapping, the number of hc's before a tire goes off is more fluid. I let the tire tell me when she's had enough regardless of HC's.
I think most of the group in this thread is referring to hc's in a 20 min hpde session at a brisk pace. When racing or doing extend lapping, the number of hc's before a tire goes off is more fluid. I let the tire tell me when she's had enough regardless of HC's.
Shariff -> Dez
I agree, I don't count heat cycles and it's certainly reliable to suggest that the harder you drive a tire, the quicker it will fall off as with anything. I'll bet you probably will get faster HC's out of a tire in the winter than the summer. The determination of how many HC you get is directly related to how much the tire falls off and how much less pace you can stand before you give up on them (hoosier R6/A6). Other tires you can run HC to the cords within a second of the pace so it's not really about HC's per se, it's about tire wear.
But my simple point is that if we are talking about THE SAME driver, the longer he drives that tire per HC has a direct effect on how many heat cycles they get. Let's say a whole 60 second session at the end of the day with Chin (if your gas tank can last that long). You can't tell me that would be the same wear as a session that got black flagged after two laps. Because it's simply not.
And that's not even bringing track conditions into play. You certainly won't get as many heat cycles at CMP or Talladega as you will at Road Atlanta or Barber. So you can't stamp a number on a tire and say you'll get X amount of heat cycles because there are far too many variables.
#60
08-13-2010, 06:43 PM
YMMV per tire, but what a HC is won't.
Heat cycle
A tire that has been heated up through use and then cooled down has experienced one heat cycle. This often results in a slight hardening of the tire compound, which can make the tire perform at a high level for a longer period of time.
A tire that has been heated up through use and then cooled down has experienced one heat cycle. This often results in a slight hardening of the tire compound, which can make the tire perform at a high level for a longer period of time.
http://www.hoosierracingtire.com/Tctips.htm
http://insideracingtechnology.com/tirebkexerpt3.htm
Some folks don't have the luxury to burn through tires without cost considerations. The number of HCs is relevant in terms of cost/longevity. For some, reduced grip for more HCs is a great selling point. Thus the need for a metric by which to evaluate longevity, i.e., the heat cycle.
-td
Last edited by himself; 08-13-2010 at 06:46 PM.