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      12-20-2012, 10:18 AM   #23
robertm
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If tires are getting greasy then you are starting out with too much pressure. Get a $15 digital gauge and figure out what you need to be at cold to achieve a hot pressure that isn't greasy. (Yes the cheapo digital ones are more consistent than the $70+ fluid filled Longacre units - as proved in Grassroots mag (?) comparison).

Remember though this isn't a set and forget deal. Things like being cooler one day to the next, the temperature differential between morning/afternoon sessions, you driver harder, you driver smoother, different tracks, tread depth will all play a role in starting pressure. Ideal or target pressure will generally not change. Once you figure out that 3x PSI hot is ideal for XXXX brand tire then you will just need to play with start pressures to achieve that ultimate on track pressure. This start pressure will change based on all of the items above by a few PSI. Best thing to do is check pressures before and after each session for max life and consistency on track.

Last edited by robertm; 12-20-2012 at 12:14 PM.
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      12-20-2012, 10:32 AM   #24
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Originally Posted by robertm View Post
If tires are getting greasy then you are starting out with too much pressure. Get a $15 digital gauge and figure out what you need to be at cold to achieve a hot pressure that isn't greasy. (Yes the cheapo digital ones are more consistent than the $70+ fluid filled Longacre units - as proved in Grassroots mag (?) comparison).

Remember though this isn't a set and forget deal. Things like being cooler one day to the next, the temperature differential between morning/afternoon sessions, you driver harder, you driver smoother, different tracks, tread depth will all play a role in starting pressure. Ideal or target pressure will generally not change. Once you figure out that 3x PSI hot is ideal for XXXX brand tire then you will just need to play with start pressures to achieve that ultimate on track pressure. This start pressure will change based on all of the items above but a few PSI. Best thing to do is check pressures before and after each session for max life and consistency on track.
Quite right!

(Except for discussion of tire pressure gauges)

Neil
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      12-20-2012, 12:13 PM   #25
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Quite right!

(Except for discussion of tire pressure gauges)

Neil
Hah! I know what you're saying. I've got an uber expensive Longacre sitting in my trailer. I recently switched to digital though and have to admit it's nice not worrying about someone dropping or breaking my sensitive gauge. Plus it seems to work just fine

One further comment on what I wrote above. As long as you get your street tires two within about +/- 1 PSI of ideal hot pressure you will be good to go. So if 35 is ideal, 34 or 36 will be just fine.
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      12-20-2012, 03:32 PM   #26
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Originally Posted by robertm View Post
If tires are getting greasy then you are starting out with too much pressure. Get a $15 digital gauge and figure out what you need to be at cold to achieve a hot pressure that isn't greasy. (Yes the cheapo digital ones are more consistent than the $70+ fluid filled Longacre units - as proved in Grassroots mag (?) comparison).

Remember though this isn't a set and forget deal. Things like being cooler one day to the next, the temperature differential between morning/afternoon sessions, you driver harder, you driver smoother, different tracks, tread depth will all play a role in starting pressure. Ideal or target pressure will generally not change. Once you figure out that 3x PSI hot is ideal for XXXX brand tire then you will just need to play with start pressures to achieve that ultimate on track pressure. This start pressure will change based on all of the items above by a few PSI. Best thing to do is check pressures before and after each session for max life and consistency on track.
Yes, I usually always have my gauge an play with pressures. On past few track days I had got this setup right, but those were in winter. Obviously warmer summer temps play a bigger role than I anticipated and starting temps must be lowered.
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      12-20-2012, 03:48 PM   #27
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Yes, I usually always have my gauge an play with pressures. On past few track days I had got this setup right, but those were in winter. Obviously warmer summer temps play a bigger role than I anticipated and starting temps must be lowered.
For ambient temps, 10 degrees F = 1 psi.

If I set tire pressures in am during first track session of day, I'll bleed out 1 psi for each increase in ambient temps of 10 degrees.

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      12-20-2012, 05:53 PM   #28
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Noted, thanks. They seem like a great bit of kit. Are the $500 each or per pair? How long is the install?

$529 for the pair. no other parts needed. Install is approx 2-4 hrs.
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      12-20-2012, 09:20 PM   #29
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You're not going to find a better all around performance tire than the PSS.

As Neil stated, max hot pressure for PS2 and PSS is 37 psi. Back when I maxed out my stock camber, I ran +38 psi hot and noticed more wear in the middle of the tread.
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      12-22-2012, 06:40 PM   #30
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No, not even close.

Water evacuation will suffer some, but you can stay with them to they're beneath the wear bars.

Plus, these clearly show that your inflations too high as there is little wear on the shoulders.

Neil
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