Take-Off Slick Tires

[2012YellowBoss]

Have some questions for Rob, our resident tire expert. I figured I would ask in public for everyone to see and help if he is able. While I was at the track I saw at least one team cleaning or scraping the tires with a heat gun. I actually stood there for 25 minutes watching them do this. Rob told me he also does the same thing with tires he uses for tracking. I gave it a try yesterday with an attachment that came with the heat gun, it worked but also bent quite easily. Today I made another attachment out of thicker aluminum and using a clamp attached it to the heat gun. It worked better but I would like to make another out of thinner but stronger steel.

Rob, what are the reasons for doing this? I understand the obvious about getting all the crap out of the contact patch and also the pickup. However I can only assume by the time I drive on pit road to the track I will have picked up all kinds of stuff. Does cleaning the tires of the old stuff really help?

I found they are much sticker after I do this, even a day after the cooled off. Does getting the top layer off make the tire (almost) like new again or at least work a little better? I certainly hope it helps here since it was a lot of work doing this.

I also see now there is (maybe) a new compound in the 285's I have. The tires with the old yellow lettering are still marked like last year but these are marked "G6000". They seem to be softer and sticker then the other compounds, at least after I cleaned them.

I was able to talk with two very cool tire guys about pressures. Going back to a long thread LS110-John started about blowing these tires on track, it looks like I was wrong (once again) about the pressures for these. While the 275 CTSCC slicks work well and wear evenly at 39-41 and even a pound or two more if you have the starting pressures off, these TUDOR series tires need about 28PSI. We even talked about the weight of the Mustang and they both agreed on that pressure. I was running 36 and keep wearing the middle out (common sense there). So I am going to try the lower PSI and see if they hook up better.




This is one I cleaned yesterday - on the left of this pair and the other before cleaning. I'm sure you do a better job Rob, after I did a couple of them I started to get better:


Some I did today with the attachment I made, you can see the difference in pic two as I was working:

 

[blacksheep-1]

I took an old steel scraper and broke the plastic handle off, then I hose clamped it to the end of the heat gun, that way the heat blows directly down the scraper and pre-heats the rubber in front of the scraper.
I am a big fan of tire scraping, however some people feel this is a worthless endeavor for the reasons you mention (pick up in the pits), I like to do it because I'm anal retentive about tire prep and won't put a driver out on the track without my best effort. I think the tires are softer as well, it's almost like the pick up acts like an insulator and won't let the tires "breathe".
I have no experience with the "tudor" tires, my general thought process is that the "tudor" cars are much lighter and therefore can use a softer compound..not necessarily the best choice for the "stock" type cars we run. Do you know who builds those tires in the pic?
Also checking tire temps would have told you the answer on pressures before you asked those guys.

 

[2012YellowBoss]

I was not getting higher center temps, believe it or not. The center wear was not crazy, the tires still lasted for a while and by the time the centers were worn the outside and inside were getting down themselves.

I am a big fan of tire scraping, however some people feel this is a worthless endeavor for the reasons you mention (pick up in the pits), I like to do it because I'm anal retentive about tire prep and won't put a driver out on the track without my best effort. I think the tires are softer as well, it's almost like the pick up acts like an insulator and won't let the tires "breathe"

OK, I wanted to see what you thought since I respect you knowledge and experience here. I'm not sure what many tracks are like on the schedule but Sebring would have to rate close to number one in picking up crap on the way to the track. The rear paddock had all kind of garbage from butts to screws and razor blades, then you have to use the "regular" use streets to get to the pits. At other tracks here it is less of a problem. The main reason I tried it is because I have been having some bad balance problems lately and think this may help with that. After seeing it done I figured I could try.

I have no experience with the "tudor" tires, my general thought process is that the "tudor" cars are much lighter and therefore can use a softer compound..not necessarily the best choice for the "stock" type cars we run. Do you know who builds those tires in the pic?

I assume many of the cars are lighter but some like the Aston's must have some weight in them? After mounting two of them today I think the sidewalls are also stiffer. It was difficult to get them to seat, the 275's are much easier to mount. It is funny you mentioned you do not know about the TUDOR tire's, when the subject turned to the CTSCC tires the guys had no idea.

They all came off the Hoosier truck so I am guessing they are Hoosiers. Some teams were running Michelins (old ALMS) and others had the Conti's with the two different types of lettering. I did not ask but it looked like the tires in the pic were replacing the older style and some teams were running left overs first. I am interested to know if the compound is in fact different and if so will it carry to the CTSCC series.

 

[ArizonaBOSS]

Wow those tires look almost brand new after scraping.

 

[blacksheep-1]

I wonder what Hoosier compound they are?

 

[steveespo]

Scott
I posted a picture in the Grand Am at Lime Rock thread of the recommended tire pressure sheet posted at the Continental Tire mounting trailer. It said 30F 32R for the Porsches and 32F/R for all other makes cold minimum. Is that what you have been starting at to get to 39-41 hot?
I will be running the Conti take offs next spring after running old Pirelli Ferrari Challenge tires last year.
Steve

 

[blacksheep-1]

You guys could do yourself a big favor and find a tire source (of a particular brand) and stick with them, I'm never going to get you guys in the ball park if you keep changing sizes and compounds.

 

[2012YellowBoss]

Scott
I posted a picture in the Grand Am at Lime Rock thread of the recommended tire pressure sheet posted at the Continental Tire mounting trailer. It said 30F 32R for the Porsches and 32F/R for all other makes cold minimum. Is that what you have been starting at to get to 39-41 hot?
I will be running the Conti take offs next spring after running old Pirelli Ferrari Challenge tires last year.
Steve

That was for the CTSCC 275's correct? I start mine at 28 and 28.5 cold. I find an increase of 10-13 pounds depending on the conditions. I could actually start a pound lower but I find the first session have the most traffic, the air and track are cooler and I don't drive my best in the morning sessions. I rarely find I get to full pressure on the first runs. However by the afternoon as the field thins out and I am running better the pressure, sometimes it get to 41-42 and I need to let a little out. If I can get a few clean hard laps in before lunch and set the tires to 39 hot I am good for the rest of the day.

Again as Rob would tell us it all depends on factors like outside temp or track temp etc. Another thing Rob recommends is checking the cold pressure when you get home. If you had the correct hot setting then this will give you a great starting point next time out.

The Rolex or TUTOR tires are a whole different animal and was told about using 28 hot last weekend. I will try them this weekend and see what happens. I will start at or above 20 with them.

I wonder what Hoosier compound they are?

That is for you to find out this year ;D

I would like to run the 275 square setup to make life easier but having the extra width in the back is worth the trouble for me. The car still sticks well with the 275's when I go squared. Besides I like tinkering with stuff, gets boring once you have everything figured out, right?

Wow those tires look almost brand new after scraping.

Those pictured are two years old from Dean's 59 FR500 car run at Daytona! They are not even the Indy compound and it answers the "you can't run these if they are more then a year old" They still stick fine.

 

[ArizonaBOSS]

I think the real question would be to test the durometer of the tire before and after scraping, and compare those figures to a new R6 or similar tire, for reference.

I'm really contemplating whether I want to buy 3-4 sets of sticker (but old) 285/645 Rolex GT-Os from Hoosier Discontinued stock or just get 5 sets of 305/645 P-Zero slick scrubs...pricing is pretty similar.

 

[Roadhouse]

I think the real question would be to test the durometer of the tire before and after scraping, and compare those figures to a new R6 or similar tire, for reference.

I'm really contemplating whether I want to buy 3-4 sets of sticker (but old) 285/645 Rolex GT-Os from Hoosier Discontinued stock or just get 5 sets of 305/645 P-Zero slick scrubs...pricing is pretty similar.

I REALLY like the pirelli slicks... I plan on using them all next season

 

[ArizonaBOSS]

I REALLY like the pirelli slicks... I plan on using them all next season

Yes I REALLY like them as well...

 

[ls110]

Were are you guys sourcing the Pirellis from??

 

[Roadhouse]

I get mine from jbracingtires.net

 

[ArizonaBOSS]

I made a deal with the devil earlier this year.

 

[ls110]

I made a deal with the devil earlier this year.

I was able find the jbracingtires.net site and thankfully... I had no luck finding the devil, at least today anyway.

 

[blacksheep-1]

I think the real question would be to test the durometer of the tire before and after scraping, and compare those figures to a new R6 or similar tire, for reference.

I'm really contemplating whether I want to buy 3-4 sets of sticker (but old) 285/645 Rolex GT-Os from Hoosier Discontinued stock or just get 5 sets of 305/645 P-Zero slick scrubs...pricing is pretty similar.

the issue with that is the new stickers are almost always going to be stickier, remember the first 3-5 laps (maybe less) are going to be the fastest laps of a tires life. Breaking them in in short heat cycles is the best method of break in. Going out and running hard for half an hour is not a good idea on a brand new set of tires.

 

[ArizonaBOSS]

I was able find the jbracingtires.net site and thankfully... I had no luck finding the devil, at least today anyway.

I got a bunch from a local friend that works on a PWC team, thinking of buying a bunch from the guys at GTTrackdays.

 

[Roadhouse]

I was able find the jbracingtires.net site and thankfully... I had no luck finding the devil, at least today anyway.

I usually just call John at the number listed on the site. Their website is less than helpful as I'm sure you found out

 

[2012YellowBoss]

I'm really contemplating whether I want to buy 3-4 sets of sticker (but old) 285/645 Rolex GT-Os from Hoosier Discontinued stock or just get 5 sets of 305/645 P-Zero slick scrubs...pricing is pretty similar.

The Pirellis are better from what I am told by racers that have run both. I have never run them so I can not say from experience. If you get them with good life left I say get the Pirellis. The Conti/Hoosiers selling new are not that old, many cars were still running them last weekend so don't worry about the age.

the issue with that is the new stickers are almost always going to be stickier, remember the first 3-5 laps (maybe less) are going to be the fastest laps of a tires life. Breaking them in in short heat cycles is the best method of break in. Going out and running hard for half an hour is not a good idea on a brand new set of tires.

True but for my track day purposes these are a no brainer, you can not beat the cost ;D There is not way I could run as many track days if I was paying $1400 or more for new tires. I have put so many of these tires through many heat cycles and they still work (maybe not for a pro driver) for someone still learning. Again those tires pictured, have been run at least four days and are two years old. I wish they would heat cycle out or wear already so I can get a fresh set on. I took off two tires in pairs the last two times I cut one of them so I could mount and try out the GT-I's. I have a set mounted that have one heat cycle of twenty five laps at Daytona, which at least for me has been the track here that is easiest on these tires.

 

[blacksheep-1]

It has been my perspective that the Conti GS tires drop off quick (but most tires do) but that they hang in their for a long time until they are fully used up. I could tell you about a set of rains..err no, no I can't