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Hoosier Product Bulletin

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Fabman

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Pleasanton: 1/2 way between Sonoma and Laguna Seca
That's exactly the one I own, I keep one with each team with a digital pressure gauge and a backup gauge. I own them, they're mine, no one uses them unless they ask me first, I send them all back to Longacre at least once per year for a checkup, if I drop one, it goes back to Longacre. I expect all of them to read within .1 of each other.
I still have my Afco pressure gauge and other setup gear from back in the day that goes in what was affectionally known as:
"The Magic Box" by competitors because whenever I showed up in somebody's pit with it, they magically got faster.
The pic was from the resurrection of the famed magic box after it had been run over and buried in my tool box for some 25 years.
I should probably update that pressure gauge as well, but damn this stuffs got some history, hard to retire everything.
Maybe I'll make a decoupage out of it. :rolleyes:

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Fabman

Dances with Racecars
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Pleasanton: 1/2 way between Sonoma and Laguna Seca
I asked this question months agonwhen i first use A7
Hoosier told me 42-44psi hot. I think is just crazy. Isn't 50 the limit?
I think is nore related to liability issues they had in the past? Maybe the side wall is too soft to start so low?
I just don't feel safe running so high psi.
 
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we're talking banks here guys, not road courses, I'm unaware of any issues with Hoosier tires in the past, I've never had a problem with their product
 

steveespo

Lord knows I'm a Voodoo Child
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Rob, wouldn't the camber advice only apply to the left side tires? Negative on the lefts on the banking will put the tire more on the outside shoulder not less correct. NASCAR guys run positive left side camber. At Daytona I was planning on running LF -1.5, RF -3.0, LR -1.0, RR -1.5 with R7s and Michelin S9s R7 at 31 hot left side and 34 hot right side. Your opinion will not be legally bearing LOL.
Steve
 
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Rob, wouldn't the camber advice only apply to the left side tires? Negative on the lefts on the banking will put the tire more on the outside shoulder not less correct. NASCAR guys run positive left side camber. At Daytona I was planning on running LF -1.5, RF -3.0, LR -1.0, RR -1.5 with R7s and Michelin S9s R7 at 31 hot left side and 34 hot right side. Your opinion will not be legally bearing LOL.
Steve
That sounds pretty reasonable, although the last Mustang that I brought across the line at Daytona had a blistered INSIDE RF, which came as a bit of a shock to me.. I wasn't expecting that
 
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just so we know the type of loads we're dealing with, this is Preston's T2 car at Homestead on 275 Hoosiers, also, IMO I don't think, that when you run a tire this small, that a harder compound will help you, I think the forces transcend that and it strictly becomes a matter of loading.

Pdh3I2Ll.jpg

a better pic, notice how the tire is doing everything possible to pull itself off the bead.

F6Z2WGJl.jpg
 
531
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sfo
Can a statement be made if on banking and tires start all at same pressure and generic front engine car, what are the relative pressures at each corner?
 
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Every track is so different, I'd start the right front at least 2.5 psi lower, the RR 1.5, again, if you're running nitrogen. If you are running air, I don't know, hopefully it's dehumidifier air because if the humidity is too high the psi will run away with you
 
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Every track is so different, I'd start the right front at least 2.5 psi lower, the RR 1.5, again, if you're running nitrogen. If you are running air, I don't know, hopefully it's dehumidifier air because if the humidity is too high the psi will run away with you



So the right side gets hotter and the RF is the hottest tire. That makes sense to my brain.



Rob, wouldn't the camber advice only apply to the left side tires? Negative on the lefts on the banking will put the tire more on the outside shoulder not less correct. NASCAR guys run positive left side camber. At Daytona I was planning on running LF -1.5, RF -3.0, LR -1.0, RR -1.5 with R7s and Michelin S9s R7 at 31 hot left side and 34 hot right side. Your opinion will not be legally bearing LOL.
Steve

So steve is throwing me off. The hot pressures are measured in the hotpit I would assume. Why would you run the right side hotter on purpose? Wouldn't you want to do something like what Rob said above and drop the pressures of the right side so the pressures are more balanced left side to right side unless your pyrometer tells you otherwise? Also, is steve in a gt350? I would think you might want a staggered camber on a track like Homestead to max your grip and speed on the banking. But at Daytona the banking is so steep I would think you would be flat on the gas and be power limited such that the camber will not matter. Max speed will not allow that car to creep up the banking such that the friction of camber would prevent the creep. Running at Daytona in a power limited car is like the infamous motorcycle guy riding the "wall of death".
 
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I don't think that's what Steve is trying to imply, he's running less camber on the left side, realizing that, that tire will not lean over as much as the (highly) loaded right side tires, so there is less reason to run that much camber, a lot of guys will run lighter springs on the left as well... but that's a whole different deal that you only see on ovals. Also, you only see that oval for maybe half of the track, you still have to get around the rest of it, so if you set up strictly for the oval, you're going to give up a bunch elsewhere. Take a look at this late model, this is an extreme example (and is a "bump stop car") but it illustrates my point, on a (fairly) constant state oval track, they run this much positive camber on the left front so the car will handle the center of the corner, and under hard braking. So you'd run less (negative) camber on the left as compared to the right, the right would run a lot more (negative) camber because that tire is loaded more.
With regards to the tire pressure, if the right side builds more pressure during the run you'll need to start that tire lower to get the correct hot pressure. I believe, and I'm not trying to speak for Steve, that this would be a max pressure for the right, so it would be less in the infield, prolly matching the lefts. Remember where pit lane starts at Daytona, and that's where you take the pressure samples. I'm not sure that's going to work, but he's thinking and I can appreciate that.

uW6nIJSl.jpg [/QUOTE]
 
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steveespo

Lord knows I'm a Voodoo Child
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So the right side gets hotter and the RF is the hottest tire. That makes sense to my brain.





So steve is throwing me off. The hot pressures are measured in the hotpit I would assume. Why would you run the right side hotter on purpose? Wouldn't you want to do something like what Rob said above and drop the pressures of the right side so the pressures are more balanced left side to right side unless your pyrometer tells you otherwise? Also, is steve in a gt350? I would think you might want a staggered camber on a track like Homestead to max your grip and speed on the banking. But at Daytona the banking is so steep I would think you would be flat on the gas and be power limited such that the camber will not matter. Max speed will not allow that car to creep up the banking such that the friction of camber would prevent the creep. Running at Daytona in a power limited car is like the infamous motorcycle guy riding the "wall of death".
Bob, Standing the left side tire up on the banking is not for grip, but to reduce dragging the inside shoulder on the banking and down the straights. I run my 2018 car and related to other NA Mustangs, even GT350s it is certainly not power limited, at Daytona Nick's race car ran 171 mph, my car ran 169.8 and it's 550 lbs heavier. The pressure differential is an estimate and takes into account the recommendations from Hoosier and Michelin for banked tracks, the higher hot pressure provides increased load rating. These numbers will be adjusted per pressure and tire pyrometer readings. We are amateurs but try and act like professionals on track. At Daytona all of the high speed corners are lefts, including turn 1 and the kink between the horse shoes. The rights are relatively slow so the 1.7 degrees of left camber will give up a little but not that much, I believe the gains in speed on the Speedway will offset the losses on the infield. As another example at Lime Rock last weekend which is 7 rights and a left I ran 3.2 degrees camber on both sides, after 2 hours on a set I found inside shoulder wear on the Right Front. To me this was an indication of dragging that inside shoulder in the right turns and I could (should) have reduced the right side camber. I digest everything Rob and AJ Aquilante post or tell me, they really focus on tire management through setup. I may not always succeed but am always thinking.
 
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With regards to a higher load rating, this is true, but it comes with a caveat, it is pretty standard for tire manufacturers to tell customer to increase pressure in the banks, the problem is, and this is not every case, that if you run a small tire on a heavy car (the example of the red mustang) you band aid the RF by increasing pressure BUT eventually, that tire will meet it's max load capacity , or simply become worn and greasy, and will lose grip, when that happens, with increased pressure, the front will slide, the driver puts in more steering input, the tire gets hotter, increases pressure, the car slides, on and on.. the driver inputs even further and you blister the tire or worse blow it out. You go down this rabbit hole of tire degradation, and you cannot ever get out of it. This is why, on some tracks, you have to "breathe" the tires in the bank, it sounds counter intuitive, but if you want the tires to last the full race, you need to manage them.
Remember I said somewhere above that the issue is not compound, but a load issue, increasing pressure increases the load characteristics, but if you are running a small tire on a heavy car, at some point, you have to give that tire a break or you will simply lose it completely.
This is a car that came across on an oval in 3rd place, I managed the tires on top 3 cars, the right front on everyone was similar to this one (this was the worst, however) this is not a setup issue, ( in fact. I would say the setup was bang on considering the circumstances) it's simply life by the rules, this was a 40 minute race and the tire was a scuff to begin with, (maybe about 3 laps) to try and make it last.
With regards to the "cut" you see, some of that might be from the fender, but I think most of that is where the tread area is trying to separate from the carcass and the sidewall, you can also see how far the car rolled over onto the sidewall of the tire in the bank.
Note that this tire never blistered, it was simply worn out, it did it's job.
This is as good as it gets, this is also why I lose sleep at night, trying to find that edge and not go over it.

rbt9RVV.jpg
 
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