Tire pressure
- Thread starter Bagman
- Start date
tfeverfred
Well-Known Member
I used to run 26 on the front and 28 on the rear. That's about as low as I'd go. If you dropped it anymore, you'd never feel the difference, but it will reduce the life of your tires. That's MY experience with tire pressure.
Indycars
Well-Known Member
As long as I keep the fronts at 35 psi, I don't have any problems with the wheels
bouncing. The backs I'm running at 12 psi, could go lower and don't think you
could tell by looking. I just don't want the tires turning on the rims under hard
acceleration. I've marked the rims and tires and no problem yet.
bouncing. The backs I'm running at 12 psi, could go lower and don't think you
could tell by looking. I just don't want the tires turning on the rims under hard
acceleration. I've marked the rims and tires and no problem yet.
tfeverfred
Well-Known Member
OP, what size tires are you running?
tfeverfred
Well-Known Member
Wow! 205 in the front. 26 may be too low. I'm really not sure. I ran 165/15's. Old VW tire size.
fletcherson
Well-Known Member
Too soft and they may want to bounce or wobble on you. How stiff are your springs? Any chance of removing a leaf to soften the ride?
Currently not having any driveability issues. Unknown spring stiffness. The ride isnt bad. Just mainly wondered what everyone was running for tire pressure. At 32 i could definitely feel the hardness of the tires. Ran 28 then dropped to 26. Didnt really plan on going any lower. These dang cars are so light i figured you could go with a little less pressure.hell at 26 psi my tires are still a tad rounded at the tread
Larry Ploghoft
Member
I run 155R15 in front at 24PSI and 29X18X15 on rear at 10PSI. All are Radials and it drives good with this pressure
Well my thinking on this is when the tires are inflated too much it gives you an unnecessary rough ride. On my car when i ran 32 lbs in my tires and drove some of these crappy roads around here it just seemed to rough. Dropping a few lbs made a big difference.
An example is, i live on a dirt road and it gets washboarded. In my truck with no weight in the bed it slides around etc. On my car being so light and with higher pressure it would feel similar on rough roads. Dropping the pressure a few lbs made the tires stay in contact with the road.
Another way i was thinking about this, and i could be way wrong. If my tires max inflate on sidewall is 44lbs and the tire is rated for 1660 lbs at that pressure, that gives you 37 lbs of weight carrying for each lb of pressure. If i run 26 lbs in my tires it gives me 962 lbs of weight carrying cappacity per tire.
Like i said, i could be way wrong on this thinking.
Like i said, i could be way wrong on this thinking.
tfeverfred
Well-Known Member
It looks like, in the end, all you can do is see what works best for you and your car. Too many variables for a definite conclusion.
fletcherson
Well-Known Member
If you think about it, there is a direct corolation between weight and pressure. Also side wall height and construction. It would be very difficult to put a generic number to accommodate the variables. Trial and error seems like the best option. There is likely data available to account for the vehicle weight/psi ratio, but I don't know where to locate it right off. Goodyear states that running a tire 20% under inflated mandates dismount and inspection by a "qualified trained" technician, but there was no mention of vehicle weight in relation to inflation. I presume they are referring to tires that are being loaded to their load range. Out of curiosity I looked on line, there are many manufacture sites with related info, but I didn't see anything definitive right off.
tfeverfred
Well-Known Member
I've still got 2 sets of coil springs from trying to find the right set that ended up on my old T Bucket. Sometimes, ya gotta play around and see what happens.
That's what SHE said!
That's what SHE said!
fletcherson
Well-Known Member
Right, and with tire pressure, you may have to run lower PSI with no passenger and on certain roads, and a bit higher with a passenger or on freeways, etc... Sort of like tuning Holley carbs, depends on the weather, lol!I've still got 2 sets of coil springs from trying to find the right set that ended up on my old T Bucket. Sometimes, ya gotta play around and see what happens.
That's what SHE said!
JeffK
Member
I suppose you would also have to consider expansion rates, the car in my avatar (2450 lbs) we would run 8 psi in the tires but after an 8 lap heat race (3/8 mile track) the pressure increase was 3-4 psi, a huge diff in handling characteristics, perhaps even a contributor to the T's fishy front ends. surely there is disproportional expansion on a street tire as heat builds up? Of course if you air with nitrogen, no worries
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