282 KPH today!

[R3v]

What is recommended pressure? I have 2.2 - 2.4 on 255/40 R19. Need to check a door sticker for that, completely forgot about that one.

Sponsored

 

[friendgr]

In Malta at the moment. Will post up the dash cam vid when I get home.

we're waiting....:first:

 

[Glenn G]

we're waiting....:first:

Oh Crap, forgot about it after vacation!, I looked but it had been overwritten

Just Enjoy the Dash cam vid of me against that Audi S5, I hit 264 on that one!:cheers:

 

[TurboGlen]

As the tire warms up the water vapor in the air inside of them heats up and expands very quickly. since water is non compressible the pressure rises quickly.
Be careful running less than 2 bar on your low profile wheels, a pot hole could destroy one instantly!

While the principle of tire pressure increasing with temperature is correct you are slightly off on the Physics behind it unless you have liquid water in your tires and are exceeding the boiling point. Liquid water is non compressible but water vapor found in air is compressible. Each different element in the air mixture has a vapor pressure which changes with temperature. Some element's vapor pressure changes more than others with the same temperature change. Water has large changes in vapor pressure while Nitrogen has small changes in vapor pressure given the same temperature change.

Sorry for the Physics lesson but the engineer in me couldn't resist

 

[Glenn G]

While the principle of tire pressure increasing with temperature is correct you are slightly off on the Physics behind it unless you have liquid water in your tires and are exceeding the boiling point. Liquid water is non compressible but water vapor found in air is compressible. Each different element in the air mixture has a vapor pressure which changes with temperature. Some element's vapor pressure changes more than others with the same temperature change. Water has large changes in vapor pressure while Nitrogen has small changes in vapor pressure given the same temperature change.

Sorry for the Physics lesson but the engineer in me couldn't resist

You are right but I usually find droplets of water (not alot mind you) in most tires that have been on for a long time. Just dismount a cold tire in the winter to see what I mean. We both agree that water vapor expands much more than air when heated, even at far less than boiling point, and is far more resistant of compression than our normal Nitrogen-Oxygen-Hydrogen and various trace gases mix, atmosphere. I admit I oversimplified the explanation on tire pressures as I didn't feel the need to explain vapor pressure at temperature in addition to dew points at temperature and pressure on a speed thread it is much simpler to say water is not compressible as most people have heard at some point. :cheers:

I'm in IT but began studing engineering before I switched over

 

[R3v]

Well, at the end of the day, you're just a casual Glenn and he's a Turbo Glen :lol:

 

[Glenn G]

Well, at the end of the day, you're just a casual Glenn and he's a Turbo Glen :lol:

I guess I need to go aftermarket:doh:

 

[Notes]

Thanks Glenn!

Just been experimenting and as said, 2.2 when cold. Went up to 2.7 after a bit of fast driving. But somehow the car felt better today :shrug:

Anyway, sometimes I find the ride to be a bit "jittery", as in bouncing so I may actually bring the pressure down to 2.0 or 2.1 just to try.

Was at 2.4 square when the tires are warm lately, yesterday I set them at 2.5 and on my drive home I noticed the pressure monitor go up to 2.7 & 2.8, also the car felt bumpy and the wheel hop increased so I might redo it today.

 

[MustangMustHaves]

That's how mine have been from the dealer. 2.4 when cold 2.7-2.8 after a long drive. So if that feels bumpy, what pressures are you going back to then?

 

[Notes]

That's how mine have been from the dealer. 2.4 when cold 2.7-2.8 after a long drive. So if that feels bumpy, what pressures are you going back to then?

2.5 feels best to me, that would be 2.3 when cold. So I don't know why they showed 2.8 yesterday as it was only a short drive back & forth to gas station in wet conditions. The guy at the gaspump was surprised how much tear my rear tires already have after 8500KM.

 

[NewMustangDE]

2.5 feels best to me, that would be 2.3 when cold. So I don't know why they showed 2.8 yesterday as it was only a short drive back & forth to gas station in wet conditions. The guy at the gaspump was surprised how much tear my rear tires already have after 8500KM.

The Pirellis do wear quickly...

Re tire pressures, i am still driving on 2.2 when cold (becomes around 2.4-2.5 when warm) and its ok, but still considering going lower to 2.1 or even 2.0 to test.

 

[Notes]

The Pirellis do wear quickly...

Re tire pressures, i am still driving on 2.2 when cold (becomes around 2.4-2.5 when warm) and its ok, but still considering going lower to 2.1 or even 2.0 to test.

I suggested the gaspump guy that I was planning to swap the rears with the front so they could wear more even before replacing them with 4 Michelin's.
He advised against it, said it would be better to swap the rears first and later on the fronts, an idea that I don't fancy that much as I prefer 4 new ones at the same time.

 

[NewMustangDE]

I suggested the gaspump guy that I was planning to swap the rears with the front so they could wear more even before replacing them with 4 Michelin's.
He advised against it, said it would be better to swap the rears first and later on the fronts, an idea that I don't fancy that much as I prefer 4 new ones at the same time.

Exactly

 

[Robby]

Glenn,

You sure your tires can handle that speed?

 

[Glenn G]

Glenn,

You sure your tires can handle that speed?

Not quite. The tires I ordered were supposed to be Y rated 300+ kph (186+mph)
Unfortunately they were 'only' W rated 270kph (168mph) which I can easily exceed. I won't be shooting for 300 until I get a new set.

Sponsored