Tire Preasure HPDE
02-16-2008, 08:21 PM
#1
Drifting
Thread Starter
Tire Preasure HPDE
Could not find much on this topic during a search so figured I would ask here...
Is there a rule of thumb as to starting tire pressure for a HPDE in relation to track or ambient temps ? What pressure do you start out at? (firestone firehawks here)
Is there a rule of thumb as to starting tire pressure for a HPDE in relation to track or ambient temps ? What pressure do you start out at? (firestone firehawks here)
02-16-2008, 11:06 PM
#2
Melting Slicks
It depends on the Tires??? Michelin Cups 26 to 29 depending on outside temp and track temp. Different tires like different running temps and they heat at different rates. Tire manufactures list the best operating temps. JD
Last edited by JDIllon; 02-16-2008 at 11:09 PM.
02-17-2008, 11:12 AM
#3
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I do follow the sequence as set forth in the shop manual but the following is from Zeckhausen Racing:
"Bleeding is done one wheel at a time. The "old timers" will tell you to start with the wheel furthest away from the master cylinder and then work your way closer. Typically, this would mean RR, LR, RF, then LF. However, it doesn't really matter if you start with the front or rear wheels, since they are on separate brake circuits on modern cars with ABS and/or dynamic stability control systems. However, you should start with the passenger side wheel and then do the driver's side."
"Bleeding is done one wheel at a time. The "old timers" will tell you to start with the wheel furthest away from the master cylinder and then work your way closer. Typically, this would mean RR, LR, RF, then LF. However, it doesn't really matter if you start with the front or rear wheels, since they are on separate brake circuits on modern cars with ABS and/or dynamic stability control systems. However, you should start with the passenger side wheel and then do the driver's side."
02-17-2008, 05:02 PM
#4
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I do follow the sequence as set forth in the shop manual but the following is from Zeckhausen Racing:
"Bleeding is done one wheel at a time. The "old timers" will tell you to start with the wheel furthest away from the master cylinder and then work your way closer. Typically, this would mean RR, LR, RF, then LF. However, it doesn't really matter if you start with the front or rear wheels, since they are on separate brake circuits on modern cars with ABS and/or dynamic stability control systems. However, you should start with the passenger side wheel and then do the driver's side."
"Bleeding is done one wheel at a time. The "old timers" will tell you to start with the wheel furthest away from the master cylinder and then work your way closer. Typically, this would mean RR, LR, RF, then LF. However, it doesn't really matter if you start with the front or rear wheels, since they are on separate brake circuits on modern cars with ABS and/or dynamic stability control systems. However, you should start with the passenger side wheel and then do the driver's side."
Uh, wrong thread. Maybe?
02-18-2008, 12:23 PM
#5
Melting Slicks
Your experience and how hard you push your car will make a difference as well. The harder you push the car, the more heat your tires will generate = higher psi.
On cold mornings, I've been told to add about 5 psi to help the tires heat up faster. As the temps warm up (ambient and track) you will need to lower tire pressure.
My last HPDE on BFG street tires, I started out at 33 psi as it was pretty cool oustide. At the end of the session they were ~ 40psi. One session I did not check my tires and got high tire pressure warnings on all 4 tires (~44 psi). As the day went on I lowered pressure to ~28 psi before a run and would end up ~40 psi.
Others with much more experience than me will probably chime in (and may correct me) but that has been my experience. You don't want your max pressure to be more than what your tire manufacturer states. Count on an increase of 10 psi during a run.
On cold mornings, I've been told to add about 5 psi to help the tires heat up faster. As the temps warm up (ambient and track) you will need to lower tire pressure.
My last HPDE on BFG street tires, I started out at 33 psi as it was pretty cool oustide. At the end of the session they were ~ 40psi. One session I did not check my tires and got high tire pressure warnings on all 4 tires (~44 psi). As the day went on I lowered pressure to ~28 psi before a run and would end up ~40 psi.
Others with much more experience than me will probably chime in (and may correct me) but that has been my experience. You don't want your max pressure to be more than what your tire manufacturer states. Count on an increase of 10 psi during a run.
02-18-2008, 05:47 PM
#6
Burning Brakes
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Mike has had me start as you suggest about 29 cold and when they get heated up run at about 36-27. Is that what you have been running hot? (assume your on pilot sport cups R compound?)
02-19-2008, 09:08 PM
#7
Melting Slicks
02-20-2008, 05:34 PM
#9
Burning Brakes
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St. Jude Donor '10-'11
Haven't run WO's ... but a guy who does starts them cold around 30 and wants a hot off-track temp ~ 37 ... more and they get greasy.
02-20-2008, 11:23 PM
#10
I start at 30 all the way around then see. I usually end up bleeding some air during the day but don't get too fixated on chasing tire temps. 36 hot is usually pretty good.
Sorry about that.
