View Full Version : am i over inflated?
Lie495s14
11-18-2006, 09:43 PM
38psi front. 36psi rear. am i over inflated ?
i put on 4 continental ContiExtremeContact all season tires this afternoon with help of a friend. he used snap-on tire balance matchine which were able to indicate the "point" where "tire and rim should be line up". it was pain in the ass to rotate the tire onece it's on the rim(i don't know technical term for this), but was that really need? cause i don't see other balance matchine do that. anyway, i told him i want to have 38psi front and 36 psi rear as i read somewhere in our fourm this would aid the soft sidewall.
wukindada
11-18-2006, 09:49 PM
Not @ all.....I would be running 39/37:)
Lie495s14
11-18-2006, 10:05 PM
:) small relieve for me, my heart rate stablized alittle. thankx dude.
MIKEBRAVO
11-18-2006, 10:54 PM
Thats what I am running. Same Tire had them a week. I really like them. However when they were installed the pressure was a round 30. The ride was plush, but the looked low. They still look low but stick like glue. Haven't chirped yet, and heaven knows I tried. LOL
Xenonk
11-19-2006, 08:57 AM
depends on what tire size you run as well.
On some of my larger but lower profile tires, I run as high as 44/42 so really it depends on when you measured it, your tire size, and what you have been doing to get the tires that hot too.
On some track days, I could start off with 25 psi up front and as I drive for the 20 minute session, it can heat up to 35 or sometimes 38 psi.
unclemat
11-19-2006, 09:10 AM
I am also running more than recommended inflation pressure (39/37).
Btw, how does different ratio of pressures f/r translate into difference in tire circumference? Does it all? I guess not, unless the tire is not severely underinflated or something.
The reason I am asking is, of course, the requirement that all tires circumference must be close (1/8"? I forgot) to not screw up differentials.
Vimy101
11-20-2006, 11:17 AM
Running ContiExtremes 215/50/17 @ 41f/39. Great tire if not a little more floaty than the OEM Spec.B set up which is fine by me for winter purposes and accounts for my higher psi to stiffen the taller sidewalls.
No snow experience yet :icon_mad: but cold/wet performance has been fantastic.
Think snow!:)
outahere
11-20-2006, 03:08 PM
.... he used snap-on tire balance matchine which were able to indicate the "point" where "tire and rim should be line up". it was pain in the ass to rotate the tire onece it's on the rim(i don't know technical term for this), but was that really need?
to achieve the smoothest running tires, that is an excellent practice.
Lie495s14
11-20-2006, 04:30 PM
to achieve the smoothest running tires, that is an excellent practice.
Try to rotate tire on the rim was pain in the butt because rubber sticks to the rim, took 3 people almost a hour to get those tires mounted.
i'd thank the inputs from you guys, glad to know that i'm in the safe zone. but my friend pointed out this morning:"you should pump up the front a bit more, it looks low!" It must be because of the temperture this morning, around mid 30. can't wait for it to start snow now.
Vimy101
11-20-2006, 04:38 PM
but my friend pointed out this morning:"you should pump up the front a bit more, it looks low!" It must be because of the temperture this morning, around mid 30. can't wait for it to start snow now.
That is your cold inflation pressure. Drive less than one mile so that the tire heats up as little as possible to your nearest compressor and pressurize to the level you want.
And yes, think snow!:)
I generally overfill to say 40psi at a local gas station on the way home a couple miles from home, park over night, and then release excess pressure the next morning before driving.
I'm running 44/42 on the stockers. It's cool here now so I'm guessing they don't heat up all that much. No exploding tires yet.
unclemat
11-21-2006, 07:53 AM
I am also running more than recommended inflation pressure (39/37).
Btw, how does different ratio of pressures f/r translate into difference in tire circumference? Does it all? I guess not, unless the tire is not severely underinflated or something.
The reason I am asking is, of course, the requirement that all tires circumference must be close (1/8"? I forgot) to not screw up differentials.
whitetiger
11-21-2006, 08:21 AM
its 1/4" i think, not 1/8" but i could be wrong. in any case, i dont hink even a 10 psi difference from front to ear would do any damage. Just dont drive on a flat tire, but we all know not to do that anyways, right?
With viscuous diffs the tire diameters aren't gonna kill anything. This is what one of the early members stated. The Spec B might have different diffs, requiring carefull attention to diameters.
With the 'regular' LGT diffs, (the EAT anyway), you can attach and drive on the spare without harming the AWD system. That is proof about the viscuous diffs, I believe.
Vimy101
11-21-2006, 10:24 AM
With viscuous diffs the tire diameters aren't gonna kill anything. This is what one of the early members stated. The Spec B might have different diffs, requiring carefull attention to diameters.
With the 'regular' LGT diffs, (the EAT anyway), you can attach and drive on the spare without harming the AWD system. That is proof about the viscuous diffs, I believe.
Unfortunately, that is not the case. When there is a greater than 1/4" circumference in the tire size, the viscous fluid will react the same way it does when actual slip is occuring. This means that the fluid will heat and stiffen up stressing the system. The OEM spare is sized to minimize the difference in size in order protect the VLSD. It's all in the manual.