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Tire falls off cliff

bob

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I hope Rob will chime in on this thread. Has anyone ever had a set of tires seem to fall off a cliff in performance? I hear things like in F1 where a driver did not like a set of tires. I'm thinking the tire is the tire how can there be any difference in a one new set vs. another new set? I have been racing on Hoosier A6's and A7's in SCCA T2 for years. But I'm new to mustangs the biggest heaviest tire killer I have ever raced. I'm still trying to figure out tire pressures and alignment settings to max out wear and performance.

That said I had a new set of A7's I ran at autoclub speedway for a weekend for racing. No problems in fact I kept getting faster all weekend running higher pressures than we ever ran on the corvettes which were some 300lbs lighter. That's 1 qualy and 2 races on that set. I took that same of young tires to CoTA which I have not been to in about 3 years. I have no practice and just go right to qualy. I'm not trying real hard but trying to put a decent time in and re-learn the track. I set my fastest time of the weekend and I have traction control ON. I often leave TC on mt 1st session out or in the rain. I'll then take TC off the rest of the weekend and gain 1 sec just because of that. Strangely, My times got progressively worse as each session went by. The mustang was a handful sliding all over the track understeering into corners over steering out of corners as I sawed the wheel every turn. It was like grossly overinflated tires or slick track surface. I rarely spin a car but I did that on Saturday. Sunday The hoosier guy sold my the new tires out from under me when the schedule got messed up and I was on track Sunday qualy when he tried to get a hold of me. So I was forced to run the bad tires in sunday's race. I dropped out a good bit of pressure closer to what we ran the corvettes hot trying to find some semblance of grip. I have run those lower pressures before at the expense of tire life but grip was good. Tires continued to fall off and I wasn't racing, I was surviving. I was off a full 10sec per lap slower than my 1st session out when I was trying to remember the track with traction control on. Wow! I have never experienced this bad a fall off in performance. Corded tires would have performed better. I still have good tread on the bad set of tires but when my car gets to BRP this weekend you can bet those tires are going right to the trash. Has anyone ever experienced tire fall off before? I was skeptical that tire falloff was a real thing. I suck as a driver but not that bad. My 2012 times in the rain at CoTA in my T2 vette were faster.
 

ArizonaBOSS

Because racecar.
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Not sure your prior experience with the A7 but trying to run an entire weekend on those tires is a Fool's Errand. They are fastest for the first cycle, you can run an entire 45 min race on the first cycle if you have to. After that, they are pretty good until about cycle #4, but on the Mustang I could only get them to perform for about 10-12 mins on cycles after the first. Then they would either be corded or useless by the 6th cycle.
 

honeybadger

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TX
Part of this also sounds like normal COTA behavior. In my experience, the track is UBER inconsistent from mid November-May due to rains and extreme temperature changes. COTA is the only track I've driven on that's faster in 95* weather than 50*. I'd bet a mixture of tire fall off and changing track conditions.
 

Mad Hatter

Gotta go Faster
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1,883
Santiago, Chile
Only sold a very few sets of A7 tires down here, and none of them will do it again... Just to expensive (in terms of tire life) compared to the R7. That said AJ Aquilante seems very keen on them but thats at a whole different level of driving.
 

blacksheep-1

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I just saw this, I'm a big fan of the A7 compound, but you do have to take care of them and watch the pressures. for most mustangs they are good for a 40 minute race and that's about it. They do seem to fall off faster than the R7 compound, but I wouldn't say they fall off of a cliff (Pirellis .. they fall off of a cliff) I think, basically, those tires were simply wore out, a full race weekend is usually more than a set of tires, any tires, can take, use them to warm the car up, or kill them in your first practice session the following weekend, and that's the end of them.
 

bob

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Not sure your prior experience with the A7 but trying to run an entire weekend on those tires is a Fool's Errand. They are fastest for the first cycle, you can run an entire 45 min race on the first cycle if you have to. After that, they are pretty good until about cycle #4, but on the Mustang I could only get them to perform for about 10-12 mins on cycles after the first. Then they would either be corded or useless by the 6th cycle.
The A7 compound is the only tire I race since they were just available in 2014. But I ran them on lighter vettes and they worked great and had good life. My mustang min weight is 3600lbs. At first I was doing just fine on the A7's like with the vette. But maybe I'm just getting use to and faster on the mustang as I learn it. So, Yeah I guess I'm experiencing your past woes with this set's ultra short tire life. I'll be at BRP this weekend with more tires. We will see if this platform is just a tire killer or not. I have never raced the R7. Friends also racing vettes did not like them at all so I never bothered to try them.

There is a sucking sound coming out of my wallet....
 

Mad Hatter

Gotta go Faster
3,378
1,883
Santiago, Chile
My buddy has a similarly prepped S197, but on A7 tires. At one of our last track days. before the plague came, we had two sessions together. For the first 10min he was faster then me. but I kept the pressure on him and as his tires heated up he started to loose grip and I managed to real him back in, ended up finishing with 1 second faster laps then his A7 car.

Really cant say anything very negative about the R7. Lasts a long time and wins races! 🤷‍♂️. Its the cheapest alternative that can get you on the podium.

In any case have to keep track or your temps and pressures. I run a 315/30-18 square setup and try to go for 33-32 hot fronts, and 31-30 Hot rears. We check them every time the car comes into the pits.
 

ArizonaBOSS

Because racecar.
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@bob my experience with the R7 is while they are 1-1.5 seconds slower than the A, they will last the entire session, and performance will not fall off until about 15 cycles or so, although the first cycle will still be best, and the first 8-10 cycles will be useful until they get relegated to practice tires.

On the Mustang I would typically use the A7 for qualifying or time trials, I would typically only try to race the A7 if it was at Nationals (again, using the initial heat cycle on the race itself). I have raced A7s on these cars before multiple times, but after the first cycle, they die after 10-12 mins of use--so the goal is to build a nice gap in the first 10-12 mins, and defend after that.

Also not sure what sizes you were allowed to run on the Vettes per regulation, but maybe you were able to enjoy a 335mm rear tire...mostly for Mustangs we're maxed-out with 315s square until you start getting into custom bodywork and things like that. And I would HIGHLY recommend running 315s square if you want to be competitive in a car this heavy (by comparison).
 

bob

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sfo
@bob

Also not sure what sizes you were allowed to run...mostly for Mustangs we're maxed-out with 315s square until you start getting into custom bodywork and things like that. And I would HIGHLY recommend running 315s square if you want to be competitive in a car this heavy (by comparison).
Unfortunately, I am limited there as well to 295 square which just beats up the tires even more.
 

Fabman

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Pleasanton: 1/2 way between Sonoma and Laguna Seca
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How about this....direction of rotation:
Hoosier direction.PNG

I seem to remember during my Youth working as an alignment tech the tire guys would always mount tires with the Date code to the inside but my current tire guy insists that the date code goes on the outside.
Now I have something from Hoosier to show him.

Anybody pay attention to this?
 

bob

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186
sfo
By a show of hands, who here follows the Hoosier recommended tire break in procedure?
I am a follower not a leader because leading takes time, effort, and commitment. Unfortunately, no one around me runs the S550 unlike when 12+ of us raced the C5Z06 vettes. So I'm forced into taking my own tire temps and pressures to optimize what I can. I'll do it eventually but my mo is to show up and qualy then race. I never practice or test. Qualy and race sessions with impound and all are just no conducive to taking tire temps and pressures that are best done in the hotpits and I go by myself with no crew. Ah....1st world problems...

So no I never do the hoo hoo break in or follow their hot pressures because guys before me told me what to do and it seemed to work. No one I know does that break-in. I know people who have tried it and found no advantage only pain. In fact everyone on DOT's in SCCA run A7's. There are only a very few who run R's or other DOT's like BFG.
 

bob

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186
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How about this....direction of rotation:
View attachment 62730
I seem to remember during my Youth working as an alignment tech the tire guys would always mount tires with the Date code to the inside but my current tire guy insists that the date code goes on the outside.
Now I have something from Hoosier to show him.

Anybody pay attention to this?
Never and I have my own tire mounting machine and balancer. The hoo hoo statement contridicts itself saying mount this way but then it is OK to flip to even wear. The only reason to do that IMO is to know by where the code it that the tire has been flipped. But just looking at the shoulders you know.
 

Fabman

Epic Contributor
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Pleasanton: 1/2 way between Sonoma and Laguna Seca
W2W Racing
20+ Years
Never and I have my own tire mounting machine and balancer. The hoo hoo statement contridicts itself saying mount this way but then it is OK to flip to even wear. The only reason to do that IMO is to know by where the code it that the tire has been flipped. But just looking at the shoulders you know.
Its because the way the carcass is made....they want you to cure it in the proper direction, question was, which is the proper direction? Now we know.
 

bob

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Its because the way the carcass is made....they want you to cure it in the proper direction, question was, which is the proper direction? Now we know.
Well thanks for that. I learned something. I'm 99% sure no one does that but it is easy enough to do. Because of my travel race I have to pay the tire shop at the track to mount my new hoo hoos. I bet the codes will be mounted randomly by these pros who mount hoo hoos all day long. We'll see and I'll report back tomorrow.
 

Fabman

Epic Contributor
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Pleasanton: 1/2 way between Sonoma and Laguna Seca
W2W Racing
20+ Years
Well thanks for that. I learned something. I'm 99% sure no one does that but it is easy enough to do. Because of my travel race I have to pay the tire shop at the track to mount my new hoo hoos. I bet the codes will be mounted randomly by these pros who mount hoo hoos all day long. We'll see and I'll report back tomorrow.
Race tires are almost always directional, most have an arrow denoting direction of rotation.
Hoosier A and R series uses the date code to denote direction they want the initial side loading on (not necessarily direction of rotation).
Now we know which is the correct way.
 

blacksheep-1

Epic Contributor
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2,672
By a show of hands, who here follows the Hoosier recommended tire break in procedure?

What do we think....Merit....or Meritless?

View attachment 62729
True, Hoosier will only mount the tires with the date code in, the problem is when the tires are mounted at a private shop, then you have to tell them to put the date code in.
With regards to tires and wear, you have 2 choices, since the tire's best laps will be it's first 5 (I call it the filet) if you qualify on stickers, and why wouldn't you? then you will get the fastest laps right off, you may have to have a set of qualifying pressures and race pressures, but that is another topic for another day. The problem with that is, like the bulletin alludes to, you will get a shorter life out of the tire, since you are basically reaming the crap out to them as soon as they hit the track, So, that is how you qualify up front, now it takes talent to do that, you can't just go out and make laps, you have to get out, find a hole in traffic and get it done within 5 (preferably 4) laps or you are just wasting rubber. This even more important when you have to race on the tires you qualify with.
So there's that scenario, and now there's the other scenario where you follow the recommendations and break the tires in slowly, this will allow them to last longer, but... you will never get a fast lap out of them like you would by just running them hard, right out of the box.
So it comes down to whatever strategy you are going to use.
In PWC we had 3 sets of tires per weekend, we would run the car on the race set from the week before to check things out, then we'd switch to the 4 lap practice tires from the week before, these we would run for both practice sessions, then, with 5 minutes to go, we'd throw on a set of stickers for 4 laps. the reason was that your practice times put you farther forward in the qualifying queue. Those 4 lap tires would become next weeks' practice tires. You'd run stickers for 4 laps in qualifying, then park the car because you needed those 4 tires to run in the race. (those tires, after the race, would be totally junk and swapped out for 4 stickers and go in the rack for next week) The next day's race, you had 4 more stickers, (these became the following week's first practice tires) and so it would go, week in and week out.
IMSA is similar, but they use more tires because they race longer.
You will never.. ever.. beat a set of sticker tires with scuffs, it just won't happen.
 

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