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  1. #1
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    Default Tires pressure, make and compound

    I am running a road course with a Formula Mazda.I am using Hoosiers 25 compound, 13 lbs in from and 12.5 lbs in back. Are Hoosiers the best choice for non spec racing? Is 25 compound correct? Finally; am I beginning with the correct pressure?

  2. #2
    Contributing Member mikey's Avatar
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    you really need to look at some data to determine if you're starting with the right pressure. what are your temps measured across the tire after a session? what is the pressure in the tire after a session?

    in absence of a bunch of other details, if you aim to achieve approx. 21lbs hot pressure and tire temps that are even across the inside/middle/outside of the tread, then you're in the ballpark. probably aiming for surface temps between 185-225 deg F. hoosier 25's are quite soft, not sure that's what you want to run unless you have a pretty good tire budget and only run short stints, or maybe if it is cold all the time where you are.

  3. #3
    Senior Member Raceworks's Avatar
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    When I ran Hoosiers I preferred harder compounds unless it was very cold out (<60F). R35's or R45's if you can get them. If it gets hot the 25's will not last long and if it's very hot they'll blister no matter how good your setup is.

    I usually went for about 19-20lb hot on most tracks.

    Starting pressures were typically in the 15-16 pound range.
    Sam Lockwood
    Raceworks, Inc
    www.lockraceworks.com

  4. #4
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    Thank you, it looks like I am in the ballpark. I am starting with a lower temperature, but end up around 21 pounds hot. The temp is pretty even across the tire. However, it sounds like I need to go to a higher compound tire. Thank you for the help.

  5. #5
    Contributing Member EYERACE's Avatar
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    are you compressing air and thinking it's dry or getting your fill from nitrogen tanks which you know is dry? starting pressures will be different

    vote for 35's here

  6. #6
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    I'm using compressed air. Today we began at 15 pounds and hot at 21 and it stuck beautifully. We are ordering 35 compound not. Thank you for your advice.

  7. #7
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    Ordering 35 compound now. Should have read my previous post better. Is filling with nitrogen that much better?

  8. #8
    Classifieds Super License racerdad2's Avatar
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    Nitrogen is much more predictable. Compressed air varies in moisture content. You're gaining 6 #'s of pressure with air one day, maybe 4 the next. When you get consistent lap times, a pound of air pressure, either too high or too low, can make or break your race.
    "An analog man living in a digital world"

  9. #9
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    That helps a lot, thank you.

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