[gumby79]

after reading 225 posts I've only seen a few comments of rim psi strength and NO data so let us bring on a list of stock SAE wheel pressure limits set by the manufactures A: with rubber valve stem and B:metal Can a wheel off a Geo hold 65psi (as posted hear it can but should it, is it within the safety limits)

I know NOT street ,but
in stock car dirt track we ran :
12psi left front 17psi right front(outside more weight transfer from all left turns)
8psi left rear (and one size down to help turn the car ) 12 psi right rear (RR)
all tires had bead screws X4-8ea rules allowed a RR"bead lock" wheel (a clamping device to hold the tire on the rim with such low tire psi wile sideways in a corner wide open with500+ hp) . To git theas #s I would have to measure the tire temp after each session and adjust for a changing track(Tacky, Blue Groove, Dry Slick) my aim point was a tire that came off the track with a evan temp across the tread 70-130f measured with a no contact inferred (IR) thermometer and normally within 5psi of departure psi . this was proof that the entire tread patch was grabbing the same giving our team a performance advantage over guys with a bad air setup

if my setup was high : 1-2psi
the psi would go up as much a dubble (eg RR 35psi )
inside 1/3 of tread was cold center was hot, out side 1/3 was warm (the tire would grow from the air mass taking up more volume raising the psi this growing problem reduces the size of the contact patch allowing more "wheel spin " adding more heat and a compounding problem

If my setup was low 1-2psi :
tire psi 2-5 rise to perfection
the inside, center, and outside were hot . the tire would grow to be right this was the happy spot

if my set up was low 3-5psi low :
psi 5-20psi rise
on short "Heat Race" inside cold(rarely below ambient)center, outside and SIDEWALL warm to hot this is from the G-force "Rolling" the tred over )_)

the tire would build heat to fast and pass the happy spot becoming a over inflated and back to a growing problem theas nights I prayed for lots of yellows to hopefully cool the tires to optimal and that my car wasn't the cause.
inside outside references the track not position on car

rear @door placarded 80psi 1750 lbs at this tire psi notice the studs don't touch the road how can this be considered safe or cost effective the , $15ea tire, studs not doing an thing up in the air @ this psi my 2x4 open diff truck will spin out (get stuck )on snow/ice covered flat pavement hence the need for proper psi and studs tires psi was uped for towing a F250 on a car trailer
How can this tire get even wear??? the center WILL wear premature !!! how can the part not touching the ground keep up with the part doing all the work
80psi is excessive for 1750lbs

same truck front @65psi @ 2000lbs at tire nice flat contact patch 65psi more appropriate for 2000lbs
sorry I don't currently have a IR temp. gun or temps would be included

my point is that EVERY tire in EVERY position has a wight to proper psi ratio (eg 65psi@ 2000lbs and 55psi @1500lbs )check with a inferred temp gun to see just how much of your tread is working and adjust your OPTIMAL psi WILL be different front to rear because of wight bias ( typically FWD heaver front than rear 65%/35% more or less. Our race cars 40/60 split move the motor back )

in this post i kept the OD the same and changed the wheel/rim size in-effect only changing the size of the side wall as a comparison of low pro to standard to tall tires RRC yes each size has a different load rating , but IF I'M correct in my under standing the "C" part of RRC takes this into account

http://ecomodder.com/forum/showthrea...tml#post494003
Edit fix broken pictures