Tire Pressure

[slaughterj]

My stock rear tires were finally worn down and needed replacement at 21k. They were smooth in the center, with tread left on the outside, which I understand is from overinflation. However, I had them at the door-panel-recommended 29psi (and routinely checked them and adjusted them). So what are people running for pressure to avoid this problem with the stock tires?

 

[MikeR]

My stock rear tires were finally worn down and needed replacement at 21k. They were smooth in the center, with tread left on the outside, which I understand is from overinflation. However, I had them at the door-panel-recommended 29psi (and routinely checked them and adjusted them). So what are people running for pressure to avoid this problem with the stock tires?

How sad, it brought a tear to my eye just thinking about your poor Viper never spinning those tires. You may have a record, 21k miles on rears is alot. I think I had 6-7k on my runflats before taking them off for PS2's. Id have been lucky to even get 10k miles out of them.

29 Psi seems right. Thatys what I always ran. As you said, overinflation results in that kind of wear, but I wouldnt worry much. 21k is alot of miles for this car on rear tires and I ve seen wear like that on wide tires. So Id stay with 29 psi on factory runflats, and on my ps2's I bumped pressure a hair and havent noticed abnormal wear.

 

[Y2K10 SRT#39]

During the last SRT Engineers chat, they said for track work you want 38 lbs HOT for best performance.
PBR

 

[MikeR]

During the last SRT Engineers chat, they said for track work you want 38 lbs HOT for best performance.
PBR

What does that have to do with street driving, tires dont get to near the temps on street as they do on track. Track tires are usually monitored hot and cold, whereas street driving you usally find a cold setting and stick with it.

 

[JonB]

My stock rear tires were finally worn down and needed replacement at 21k. They were smooth in the center, with tread left on the outside, which I understand is from overinflation. However, I had them at the door-panel-recommended 29psi (and routinely checked them and adjusted them). So what are people running for pressure to avoid this problem with the stock tires?[/quote]

John, YOU DONT HAVE A PROBLEM, other than not enjoying your SRT Viper enough!

Your ALIGNMENT is as much at play here as the CORRECT pressure. You are highway aligned, probably factory spec (flat-footed). What this indicates is lots of highway miles, not much twisty driving, and sedate, easy throttle inputs. If you dont corner much, your shoulders will always last longer.

OE alignment + burnouts and aggressive = the same result, but in 8000-10000 miles !

ITS THE ALIGNMENT !

Generally speaking (very general) if you CROWN the tires by overinflaiting them, (or letting them get too hot on track) you will get the 'groove of doom' wearing awy the center rib. This is one reason PS-2 is so fantastic. Center rib is HARDER !! Shoulders are SOFTER.

Did you already get your tires? {I was not blessed this time? }
I SUGGEST THAT YOU WOULD APPRECIATE A NITROGEN FILL........... not atmospheric air

 

[JonB]

What does that [38 lbs hot] have to do with street driving, tires dont get to near the temps on street as they do on track. Track tires are usually monitored hot and cold, whereas street driving you usally find a cold setting and stick with it.[/quote]


Actually, if you read between the lines, it helps.

If you are a highway driver, tire temps 100-130f, take some temps when HOT and see if YOUR hot pressure is ~ 38 psi. If your performance goal is 38, you might have to start out at 32-32 cold to get there at 130f.

Or just put in Nitrogen at 38.

IM NOT SAYING TO DO THIS, but based on "SRT engineers" Paul-quoted opinions

 

[MikeR]

What does that [38 lbs hot] have to do with street driving, tires dont get to near the temps on street as they do on track. Track tires are usually monitored hot and cold, whereas street driving you usally find a cold setting and stick with it.[/quote]


Actually, if you read between the lines, it helps.

If you are a highway driver, tire temps 100-130f, take some temps when HOT and see if YOUR hot pressure is ~ 38 psi. If your performance goal is 38, you might have to start out at 32-32 cold to get there at 130f.

Or just put in Nitrogen at 38.

IM NOT SAYING TO DO THIS, but based on "SRT engineers" Paul-quoted opinions

Agreed. I just dont see many of the Street only drivers worrying or checking there "hot" temps. Otherwise as you say, theres always Nitrogen.

 

[SweetRed04]

I thought I drove pretty easy to get 13,000 miles on each set of rear tires (so far).

I have a hard time believing you have the willpower to drive that gently so often!!!

 

[CitySnake]

You may have a record, 21k miles on rears is alot.

Oh pleeze Mike. Not even close!

 

[slaughterj]

How sad, it brought a tear to my eye just thinking about your poor Viper never spinning those tires.

I thought I drove pretty easy to get 13,000 miles on each set of rear tires (so far).

I have a hard time believing you have the willpower to drive that gently so often!!!

Hah, you guys are funny! Actually these tire did get a fair amount of spin, maybe not as much as you guys, because (1) my car is a daily driver and (2) I put 80k on my 98 with plenty of spin, so I don't feel the need to spin the tires like those who only drive once a week/month!

 

[slaughterj]

[Did you already get your tires? {I was not blessed this time? }

Actually I did buy from you, but a while back!

 

[slaughterj]

So it sounds like in summary, I should just stick with the 29psi and accept that the centers will wear a bit quicker?

 

[JonB]

Quote:

Originally Posted by JonB - PartsRack
[Did you already get your tires? {I was not blessed this time? }

Actually I did buy from you, but a while back!

I know, thats why I say "THIS time"

So it sounds like in summary, I should just stick with the 29psi and accept that the centers will wear a bit quicker?

Did you say what tires you bought? You said 'with the stock tires" is that RunFlats again?
29 PSI Stock runflats yes. PS2? Hoosiers? SOB?

Tires purchased from PartsRack last longer (hot air included)

 

[OKFireChief]

This may be a silly question but ... If you want the tire pressure at 38 psi for the track and autocross, what psi should you start with? Is 38 psi the general rule for Hoosier, Toyo, Kuhmo etc??? Thanks to all!!!

 

[JonB]

During the last SRT Engineers chat, they said for track work you want 38 lbs HOT for best performance.
PBR

Check that forum

 

[slaughterj]

Quote:

Originally Posted by JonB - PartsRack
[Did you already get your tires? {I was not blessed this time? }

Actually I did buy from you, but a while back!

I know, thats why I say "THIS time"

And that's what I meant, "this time!" Only I bought them from you a while back and just now putting them on.

Did you say what tires you bought? You said 'with the stock tires" is that RunFlats again?
29 PSI Stock runflats yes.

Yes

 

[ssnaked]

If you want 38lbs hot on the track start cold with 31-33. Adjust to 38 lbs right after you get off the track. You may be off a pound or two depending on track and weather conditions so check and adjust each time you come off the track.

John
_________________
06 FE Coupe

 

[OKFireChief]

John, thanks buddy! I'll set the pressure next time out ...