hoosiers R6 experience - normal?
08-03-2010, 05:52 PM
#22
Team Owner
C5Z stock motor/drivetrain, coils.
decided to try r6. most of the time ran them about 32-34psi hot which meant starting around 26-27psi cold.
alignment is dialed in to where I have pretty uniform wear across the surface, slightly more on the outside.
first 2 events - nice grip, very fast
next 2 events - still good grip, comparable to fresh r comps maybe, upper to average range of my normal speeds/times. some oversteer starting to become an issue but controllable.
5th event - consant understeer develops after 1st session, have to slow down and back off throttle significantly going into corners compared to my normal speeds. when the rear breaks loose, pretty hard to correct/recover.
events 1, 2, and 3 had fewer cycles/sessions (maybe 13 total). event #4 was long, 6 near 30 minute sessions. i quit after session 3 of the last day because of unpredictable grip and fatigue issues, maybe related
tires are thrown away with grooves still showing about 1.5-2/32nds depth. the surface looks blistered and uneven, especially in the front - that happened at the last day as it progressed, they looked fine until then.
is this normal experience? trying a6 now hoping for a more gradual traction drop-off with heat cycles.
how do people buy these used? are you guaranteed that the tires have not had more than a few cycles? at my 3rd or 4th event it would not have been possible to tell that they are about to go from just looking at the surface
decided to try r6. most of the time ran them about 32-34psi hot which meant starting around 26-27psi cold.
alignment is dialed in to where I have pretty uniform wear across the surface, slightly more on the outside.
first 2 events - nice grip, very fast
next 2 events - still good grip, comparable to fresh r comps maybe, upper to average range of my normal speeds/times. some oversteer starting to become an issue but controllable.
5th event - consant understeer develops after 1st session, have to slow down and back off throttle significantly going into corners compared to my normal speeds. when the rear breaks loose, pretty hard to correct/recover.
events 1, 2, and 3 had fewer cycles/sessions (maybe 13 total). event #4 was long, 6 near 30 minute sessions. i quit after session 3 of the last day because of unpredictable grip and fatigue issues, maybe related
tires are thrown away with grooves still showing about 1.5-2/32nds depth. the surface looks blistered and uneven, especially in the front - that happened at the last day as it progressed, they looked fine until then.
is this normal experience? trying a6 now hoping for a more gradual traction drop-off with heat cycles.
how do people buy these used? are you guaranteed that the tires have not had more than a few cycles? at my 3rd or 4th event it would not have been possible to tell that they are about to go from just looking at the surface
If I get 4 20-25 minute sessions for three days it is a miracle. Twenty 0ne sessions 
i would be glad if they held air.
I run the higher pressures as as 95 Jersey stated starting at 31-32 front and 30-31 rear ending at 40 -41. I want to see one running in front of me with 20 start pressures.
Last edited by John Shiels; 08-03-2010 at 05:54 PM.
08-03-2010, 06:36 PM
#23
Melting Slicks
I am literally quoting the Hoosier engineer at the seminar I attended. They probably did it with a bit more eloquence, but the message is the same.
They stated when the tire was cold it would flex a bit more and provide a feeling of better grip initially. When I say roll over, I don't literally mean off the rim, I mean they just flex around a bit more than when they are hot with greater pressure. Think about it. If your approaching the tire's limit, and instead of it being rock hard and giving away, it has the ability to flex a bit, your going to get the extra bit of grip. If the tire becomes rock hard stiff due to high pressures, now you are at the mercy of the tread compound solely. The tire doesn't have the ability to provide that little bit of flex to provide that last bit of grip.
Maybe I am not transposing the information as clearly, but it made total sense in the seminar. They 100% stated that as the temp and pressure goes up, the actual traction of the rubber does not become compromised (ie. negates the "greasy" theory). The tires are just rock hard at that point and are not providing the flex that give you that extra 10th.
I think Dave's post hits the nail on the head. If 100% traction is you absolute concern, you probably want to run them a little low. If you are looking to use them over the longest period of time possible, run them higher overall.
Like I said, I run them cold at 31-32 and get great results and they last a long time. What temp they get to hot actually depends on the track, outside temp, how long I run and how hard.
They stated when the tire was cold it would flex a bit more and provide a feeling of better grip initially. When I say roll over, I don't literally mean off the rim, I mean they just flex around a bit more than when they are hot with greater pressure. Think about it. If your approaching the tire's limit, and instead of it being rock hard and giving away, it has the ability to flex a bit, your going to get the extra bit of grip. If the tire becomes rock hard stiff due to high pressures, now you are at the mercy of the tread compound solely. The tire doesn't have the ability to provide that little bit of flex to provide that last bit of grip.
Maybe I am not transposing the information as clearly, but it made total sense in the seminar. They 100% stated that as the temp and pressure goes up, the actual traction of the rubber does not become compromised (ie. negates the "greasy" theory). The tires are just rock hard at that point and are not providing the flex that give you that extra 10th.
I think Dave's post hits the nail on the head. If 100% traction is you absolute concern, you probably want to run them a little low. If you are looking to use them over the longest period of time possible, run them higher overall.
Like I said, I run them cold at 31-32 and get great results and they last a long time. What temp they get to hot actually depends on the track, outside temp, how long I run and how hard.
Also, as a company that sells something as important of a safety item as tires, do you really expect them to tell the mass public in a "seminar" that the best tire pressures for optimal grip is far below what their legal department says they need to tell people?
Oh, and lastly, your tire pressures will vary depending on: 1) your setup, 2) alignment, 3) weight, and 4) how hard you're pushing the car..
08-03-2010, 06:48 PM
#24
Le Mans Master
The Hoosier rep also laughed at myself and other T-1 competitors in my Region bc of our hot/cold pressures. But our data (time sheets, car feel, and data acquisition) clearly shows our times drop off pace significantly the higher the pressures the are. Go to the SCCA Runoffs and ask all the T-1 drivers what pressure they start at cold and finish hot..I bet they won't be anywhere near mid 30s
Also, as a company that sells something as important of a safety item as tires, do you really expect them to tell the mass public in a "seminar" that the best tire pressures for optimal grip is far below what their legal department says they need to tell people?
Oh, and lastly, your tire pressures will vary depending on: 1) your setup, 2) alignment, 3) weight, and 4) how hard you're pushing the car..
Also, as a company that sells something as important of a safety item as tires, do you really expect them to tell the mass public in a "seminar" that the best tire pressures for optimal grip is far below what their legal department says they need to tell people?
Oh, and lastly, your tire pressures will vary depending on: 1) your setup, 2) alignment, 3) weight, and 4) how hard you're pushing the car..
08-03-2010, 06:54 PM
#25
Team Owner
The Hoosier rep also laughed at myself and other T-1 competitors in my Region bc of our hot/cold pressures. But our data (time sheets, car feel, and data acquisition) clearly shows our times drop off pace significantly the higher the pressures the are. Go to the SCCA Runoffs and ask all the T-1 drivers what pressure they start at cold and finish hot..I bet they won't be anywhere near mid 30s
Also, as a company that sells something as important of a safety item as tires, do you really expect them to tell the mass public in a "seminar" that the best tire pressures for optimal grip is far below what their legal department says they need to tell people?
Oh, and lastly, your tire pressures will vary depending on: 1) your setup, 2) alignment, 3) weight, and 4) how hard you're pushing the car..
Also, as a company that sells something as important of a safety item as tires, do you really expect them to tell the mass public in a "seminar" that the best tire pressures for optimal grip is far below what their legal department says they need to tell people?
Oh, and lastly, your tire pressures will vary depending on: 1) your setup, 2) alignment, 3) weight, and 4) how hard you're pushing the car..
08-03-2010, 08:15 PM
#27
"AlohaC5" Senior Member
08-03-2010, 09:46 PM
#28
Drifting
Mark,
Ha. You'll really like these pics of my car at VIR weekend before last. After seeing these pics, I am bumping my cold pressures back up a couple of pounds. I was running the 275 A6s with 23/24 cold pressures knowing the extreme heat would put me in the mid 30's hot temps. Seeing what I found below, I think I am willing to forego some perceived grip in order to get the rims off the ground.
From what I can tell, all of these pics were from first hot laps. Good grief!!!
T15 under acceleration and compression. Even the air dam is touching:
Oak Tree under (too much) acceleration -- but, I tend to drive "loose" anyway, LOL:
Ha. You'll really like these pics of my car at VIR weekend before last. After seeing these pics, I am bumping my cold pressures back up a couple of pounds. I was running the 275 A6s with 23/24 cold pressures knowing the extreme heat would put me in the mid 30's hot temps. Seeing what I found below, I think I am willing to forego some perceived grip in order to get the rims off the ground.
From what I can tell, all of these pics were from first hot laps. Good grief!!!
T15 under acceleration and compression. Even the air dam is touching:
Oak Tree under (too much) acceleration -- but, I tend to drive "loose" anyway, LOL:
08-03-2010, 09:54 PM
#29
Melting Slicks
08-03-2010, 10:04 PM
#30
Melting Slicks
If you're doing hpde then try to find some scrub slicks. I picked up a set hoosier R80/R100's off of a porsche from Infineon for free with very few heat cycles. They were as fast or faster than A6's once heated up and last a long time. Be careful with the dunlop scrubs though. I burned through a set of those in less than a day.
I used to run the R6's for hpde and I liked them. Ran them at about 30 psi hot and after about 20 heat cycles they were hard and slippery. I do the same with the A6's now in TTS and like them even better than the R6's
.
I used to run the R6's for hpde and I liked them. Ran them at about 30 psi hot and after about 20 heat cycles they were hard and slippery. I do the same with the A6's now in TTS and like them even better than the R6's
.
08-03-2010, 10:10 PM
#31
Drifting
I run NT01s for lapping and practice and then slap on the A6s for Time Trials.
NT01s are a great bang for the buck, but are not near as sticky as R6s and a long ways from an A6.
-Kevin
08-03-2010, 10:53 PM
#33
Le Mans Master
08-03-2010, 11:29 PM
#34
Melting Slicks
Agreed. IMO, they are more predictable than R6's though and don't heat cycle out quite as fast
08-04-2010, 07:20 AM
#35
Racer
08-04-2010, 07:23 AM
#36
Racer
pics guys
08-04-2010, 09:34 AM
#38
Instructor
08-04-2010, 11:47 AM
#40
Drifting
Another thing to think about... I have been marking my tires to measure the amount of rotation on the rim during a TT session. I have seen as much as 1/2 a rim of movement in the course of three sessions, which in reality is only about 6 hot laps total. Kinda makes me wonder if I even need to balance the tires when I have them mounted if they are going to slip that much with the lower air pressures. I spoke to my guy at Discount Tire and his is going to dry mount my next set (having the As flipped as we speak) and then he is going to look into different kinds of lubricants to see if he can find one that will make a difference.
Back to the original topic: if the OP is going to go with Nitto NT01s, I run them at 27psi cold and look for 36-38psi hot.
-Kevin
Back to the original topic: if the OP is going to go with Nitto NT01s, I run them at 27psi cold and look for 36-38psi hot.
-Kevin