miamirice

I am seeking advice on preserving and best management for R6/A6 tires. These will be used for racing sprints and Enduros (prob no more than 3 hours enduro events, maybe a 6 hour)

I plan to switch front to back during or after every event. However, I have no idea how often to dismount them from the rim and switch sides.

Anybody with some experience on running Hoosiers please chime in here. I also don't know what to expect on heat cycling as the forums are all over the place with heat cycling.

rice_classic

R6/SM6 only. Cannot comment on A6

Heat cycle! Follow Hoosier's heat cycling instructions then take them off and store them for at least 24 hours (preferably a week) to "cure" after you've cycled them. This will improve their life regarding number of competitive cycles.

I've noticed that people's discussion about R6's are all over the place because A) they either are or are not cycled, B) people running the correct or incorrect pressures and C) driven incorrectly (sliding)

Pressures for FWD: 38+ PSI when hot, Hoosier even says as high as 50 but I haven't been able to make them work better above 42.

Heat cycles: Like mentioned above.

Driving: do not slide them. Drive within their slip angle and not beyond otherwise they will "fall off" before the end of the race. AKA: Hoosiers really don't like to be overdriven.

Finally, I got 12 or so cycles before they were no faster than shaved RA1s. It will be interesting if the R7's are any better/different. As it stands I've switched the RR's with no intention of switching back.

Finally, if you aren't running wider than 205/50/15 then don't buy R6's, just buy SM6's because they're like $40-50 cheaper per tire and they're just re-badged R6's for the Spec Miata guys so if running that size don't waste your money on the R6 labeled tire.

Xian

Yup, nailed it all ^^^.

I haven't run on Hoosiers since I dumped the ITA car in 2009 or so but:

Heat cycling is important (as noted above).

I never had R6's go away on me... granted this was ITA power levels and 2250-2300# with driver.

I didn't play with R/A staggered compounds or 225/205 staggered sizes but the logic behind doing so is solid.

Flipping them on the rim... I ran out of cycles before I ran into any outside edge wear problems. If you're grinding off the outside edge and need to flip the tire, there's something wrong.

miamirice

Thanks guys. Appreciate the info. I had heard some off this from a few porche-philes but they also talk about swap side to side, I think more for longevity than shoulder wear. I look forward to trying these magical tires.

I should keep better records but my experience with R888 has been 6-8 events until the grip degrades big time ( with a fair amount of tread remaining). This is of course also running them in the blistering FL summer track temps.

chargeR

I have less experience than the posters above (I've only used 1.5 sets) but I cannot agree more with what's said above. They hate too much slip angle, and will reward neat and tidy driving, and like a lot more pressure than a lot of other track oriented tyres. I ran mine at 39-40 psi.

I never swapped the tyres side to side, but I had a lot of front static camber and definitely have accelerated wear on the shoulders of the rears but I expect they would heat cycle out before I run out of tread.

This is with 275/40R17, 245/40R17 and 225/45R17 R6s, on a 2600 lb-ish DC5R. I heat cycled them as per Hoosiers instructions before use.

Xian

Don't get me wrong, rotating them around the car based on wear is important but my tires always cycled out before the "wore out" so no need to dismount, flip, and remount them.

I've got a set of R888's on my car right now... color me unimpressed. IMO, they aren't that much better than the street tire options out there currently.

miamirice

Same here. I used on 2 cars. I am trying NT-01s now, have never driven on Hoosiers.

Xian

The one thing that sticks in my mind with the first set of sticker Hoosiers I ran on track was their responsiveness at turn-in. It was literally make-me-giggle-when-I-turn-the-wheel good.

IIRC, this would have been circa 2005 or so and on the R5... I'd been used to running the Victoracer, then V700, then RA-1, and then some take off R4's.

Agent_Smith

I ran the entire 2013 season on hoosiers, coming from R888's, NT01's, RA1's, r1's, RS, RS3 & random take offs previously. Hoosier R6's turn in is GREAT, GRIP IS GREAT, predictability is phenomenal. The only downside (which is negligible in my opinion) I saw was braking lockup took longer to recover from or any sliding/break away also seemed to take longer to recover from compared to other tires, so long as you drive at 99.9% of grip level & not at 100.1% you feel invincible.
I followed the break in procedure & usually try to end up at 39PSI hot all around, 2250lb 106Hp CRX.
WEAR is the ONLY true downside of hoosiers, flipping & rotating did help me a lot, every other event I flipped them, rotating as often as possible & only used fresh ones for the races, but I was getting as few as 8 heat cycles before either cording a tire & as many as 14 heat cycles if I didn't rotate exactly on one tire, but the average for me was 10-12 heat cycles, no fade off in my experience. I drive the car hard & depending on the track have had some brief off road or 2 wheels off excursions, but that's a part of racing, in a TT setting I am certain I could have received much greater life. I also run no LSD & have inside wheel spin from certain turns/tracks
THEY ARE VERY TEMPURATURE SENSATIVE, I made the mistake of leaving tires on the car in summer in Arizona after 1 event, came back to the car 1 week later & found the sidewalls had cracked, similar to freeze cracking but not quite the same, called hoosier, they advised against running them & the cracking was from sudden temperature change, sucks because I only had 3 heat cycles on them & seems inaccurate because it’s simply hot, the high & low all week was less than a 30 degree temp difference . An expensive mistake I will only make once, I keep them indoors now under climate control.

miamirice

Good info, thanks agent Smith. This flipping as a proactive and not reactive measure is what I have been hearing from some of the Porsche guys I talked to. My first scheduled race with the car is a 200mile at Homestead on the Grand-AM roval. I will be on track with 458's/Praga type cars so my expectations are I will really do more like 120miles when those guys hit the 200mark and it gets checker flag. Would you do an event like this on Hoosiers or NT-01/R888? I am wondering if a little harder tire like this might be better. Provided the car holds up there is just 1 mandatory stop. Not planning to change drivers, just fuel.

Agent_Smith

The longest session I've had on hoosiers is 30 minutes, so long as they were not over driven the grip & responsiveness was very consistent; when a apex is missed and more turn in happens, they do respond with less grip until temps cool down again, which means driving slower that at the limit you were previously at for sometimes 1 full mile before tire temps are reasonable. 120 miles is manageable on hoosiers but I think you would have a lot easier or a time & less stressful driving if on NT01's, NT01's LAST, I have 55 heat cycles on my last set of 225/45/15's on 15x8's on a mixture of cars from 110-340whp.

One thing I did not meantion previously, is R6's LOVE CAMBER, at least in my experience, -3 or more is required, I have an average of -4 degees all around. I also run higher spring rates with hoosiers than r888's/nt01's this was a big contrast and took a few weekends to get dialed in. Way too much time wasted with toe plates between sessions etc. Once I figured out the amount of camber & spring rates the car & I liked, then I was able to get a real laser alignment.

Xian

I don't think that should be a problem... IME, R6's on an ITA car will happily do 3 hour stints with plenty of rubber left. Folks also run them on ITS/ITR/ITE/STU type cars for enduro's like the VIR 13...

rice_classic

Apologies for me being a bit pedantic but I just want to bitch and moan a bit about Hoosiers and Agent_Smith's post motivated me to do so.
You say "only downside" but then go on to list 2 others, which, IMHO are HUGE downsides due to the cost of the tire.
and
8-12 heat cycles and being temp sensitive (or what I call UV sensitive), are huge downsides. It's fascinating that Korean and Japanese tires have figured out how to put UV inhibitors in their compounds but Hoosier hasn't solved that mystery. Also, the reason I bet they're not "falling off" for you is A) you have 105HP and/or B) you're doing it right by no over driving them, staying at the 99.9% level you mentioned. Overdrive a hoosier (or lock them up) is a sure fire way to "run them out". But the other reason they don't like being locked up is that they flat spot (and cord from flat spotting) easier than any other DOT R-comp I've ever run or had experience with.



On a side note, I was at Thunderhill recently for the 25 and one of the teams I was with has multiple Hoosiers split on them where they mount on the wheel because they couldn't handle the lateral load on the backside of the bypass. The sidewall was splitting in half. All Hoosier had to say was, "Well, it was a bad batch." A BAD BATCH! I loved racing on Hoosiers when they were new to me but after knowing more about them, I find it very very hard to love them.

Xian

Wowza. Seriously? That's pretty shitty... and horribly dangerous.

I'll grant you that I never had that sort of an issue with mine but the local Hoosier distributor (Appalachian Tire) was always really good to buy from/work with.

miamirice

I just ordered SM7's. Can't beat the price at $181 shipped. I ran NT-01's and they did well, but the guy that won the sprints and was 2.5 seconds faster on everybody in class (1:34.. On the Rolex course at Homestead, was using SM7 with a car very similar to mine. I could do 1:36 at best. Anyway....what is your regiment for heat cycling and "curing" your Hoosiers? Have you used the SM7 yet?

granracing

The first session should consist of no more than 10-15 minutes of running. The early part of the session should be run at an easy pace, with the speed gradually increased until the end of the session. The final lap should be run at the fastest possible speed. The intent is to achieve maximum tire temp on the last lap. At this point the car should be brought in and the tires allowed to cool at a normal rate.

During the initial run-in process, the inflation pressure should be 3-5 psi higher than you would normally use. The best progression would have the driver taking 4-7 laps to accomplish this break-in. Each lap should be approximately 7-10 seconds a lap faster than the previous lap. The goal is to have the tire temp as high as possible on the last lap without “shocking” the tire during the warm up laps. In essence, no wheel-spin, late braking, or sliding. The last lap should be at, or very close, the maximum possible.

“Cure” Time – After completing the initial run phase, the length of time the tire is allowed to set is very important. The amount of time until the tires should be used 24 hours, not just the next day. Often times we hear drivers complain that the heat cycling process wasn’t effective only to learn they didn’t follow this time schedule and thought a few hours was good enough.

In order to accomplish this process, we’ve found it to be well worth the investment to purchase a second set of rims. Yes, it’s more money spent but in the long it run will provide a cost savings.

First, the disclaimer stuff. This is not a suggestion from Hoosier nor myself, although I have attempted it with R compound race tires. If you have the ability to put your rims and tires on a street-legal vehicle, have a safe place to take it for a drive not exceeding the speed limit, that would be better than no heat cycle at all (for R compounds). It would at least expose the tire to some abrasion, movement, and a little bit of temperature. However, do not fool yourself into thinking this method will be nearly as effective as if done on a track. I personally have attempted going around in circles at a Cul-de-sac in an undeveloped street only to get dizzy and build almost no heat in the tires. I have given thought to other contraptions such as running the tires on rollers, running lower pressures and driving the car on the highway to build up heat, but none have been close to being the same as heat cycling them on a track. I have also bought tires from a company that “heat cycles” the tires for you, but can’t say definitively if that process actually works.


I wrote an article about the topic with the help of Hoosier which can be read here (took the part out you were asking for and posted above): http://www.goaheadtakethewheel.com/b...aving-process/. Also did a test on wear with non-heat cycled and properly heat cycled. Another thing when first run and not heat cycled, the tires tend to go away more towards the end of the session versus heat cycled tires. The new compound will help with consistency.

rice_classic

I look forward to seeing how the 7's compare to the 6's regarding heat cycles, consistency etc. The SM6 was a good price too but at the rate they cycled out they were no longer were so in comparison to a Toyo RR. The one thing that pissed me off about the Hoosier is the R6/SM6 had very little rubber on it new while their non-DOT radial had a super thick band of rubber and according to Hoosier would last "3x as long". Well WTF?! Why F' over the guys buying the DOT R6's?

Granracing is on the money about heat cycling and I just want to add, that if you can buy the tire on TireRack and pay the extra $15/tire to have them pre-heat-cycled for you, it is absolutely worth the $$. Because if you think about it, having the hassle of burning a session just to cycle tires isn't money well spent either. It's just easier to show up to the track with new tires that are ready to race. My $.02.

granracing

I personally think the Tire Rack option is nice compared to not being able to heat cycle, but unfortunately really do not believe it's as good as doing it on track. I've also spoken with some people that I trust in the industry who had the same conclusions. I admit to having thought about making some type of heat cycle machine; although that wouldn't be practical.

Has anyone heard what the Tire Rack process is? Put the tires on rollers with pressure and spin them? I do find it interesting that the little knubby things are usually still present on their pre-cycled tires.

Having extra sets of wheels makes managing the heat cycling process much easier. Sucks buying the extra wheels but pays off in the longer term. I have 3 sets of dry wheels. 1 for to be heat cycled tires, 1 that are cycled and race ready, then a 3rd that has too many cycles for racing but great for practice days / HPDEs.

miamirice

Thanks for the info. I am a bit skeptical on the tirerack process too. I bought toyoRR heat cycled from them. They were totally new looking with no scuffing. I am picturing Stainless rollers, wonder if they have some data about temps that are achieved. I will check it out. I would prefer a consistent, out-of-the-box heat cycled tire (are you listening Hoosier). Never ran my toyoRR as the shop I run with got screwed on tire delivery so I gave them to another guy and ran my nt-01.

Do you guys have any ECONOMICAL tire temp gauge suggestions? The more I read it seams the IR gun from Harborfreight is almost pointless.

granracing

That is a whole 'nother big discussion on tuning. Lot of different opinions about the use of pyrometers. Start talking with some experienced people in the tire industry. You can even call Hoosier's national office and speak with them. They are super nice and willing to talk with us.

You'd be surprised with how much the tire temps change throughout the course of a lap. I don't use one other to verify a few things.

rice_classic

I concur. However, in the case of Ho-Ho's, they prefer to be "cured" for longer than 24 hours and that's an inconvenience that's hard for me to justify. I'm not one of these motorhome-enclosed-trailer-shop-owning racers. Hell, the HOA doesn't even let me store the trailer on my property. So folks like me have to err on the side of convenience. I too want to know how Tire Rack heat cycles the tires and I also want to know if actually scrubbing them is needed as part of "heat-cycling". Maybe just applying heat uniformly allows those molecules to align and being scuffed on an abrasive surface isn't needed?

Indeed and thanks to F1 we get to visualize that!

Xian

They cunningly hid it on their site...

http://www.tirerack.com/tires/tirete....jsp?techid=66

rice_classic

edit: Xian got to it before me... Oh well. Read again!

http://www.tirerack.com/tires/tirete....jsp?techid=66

I've seen people all over the place on opinions. The only universal truth I've found is that heat cycling on the track (aka wheels on the car) is more difficult to do accurately and uniformly especially taking into account different drivetrains and setups.

Example: On my light FWD race car, my rear tires are always 30 degrees behind my front tires. By the time I've brought my rear tires up to the "heat-cycle" temp, then I've over heated the fronts or run them for too long for a heat-cycle.

Tire manufacturers recommend it but none specify if machine or track is the best process. Since the tire rack machine is using pressure/friction/force to generate heat as opposed to applying the heat from an external source (like blown hot air or flame) and it's in a uniform controlled environment, it is arguably the better method.

exgr

heat cycling tires on street car makes more sense... probably just mount them to front and scrub them in. shouldn't take all that long. i like to leave them over night to ensure cooling off and "re-bonding". something i read about from autox list back in the 90's. makes sense to me. it is to get rid of mold release agents and other stuff. should apply to all tires.