Correct Tire Pressure?
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tire pressures
the tire pressures on the track vary by tire manufacure and weather. some tires work best low psi and some work best high psi. to get your tire pressures set perfect, its best to go up on a friday. it usually takes about an hour or two and lots of notes to get the tire pressures and temps dialed in perfect. do 5 laps, come in to check and take notes, air the fronts down to be the same and do the same with the rear. go out and repreat hte process until everything evens out. after that dont touch your tire pressures. in the morning, look at the pressure in each tire. they will all be different but that is ok cuz when they heat up, they will be even. take notes on the weather so next time you run there with the same weather, you already know what to se the pressure at.
the tire pressures on the track vary by tire manufacure and weather. some tires work best low psi and some work best high psi. to get your tire pressures set perfect, its best to go up on a friday. it usually takes about an hour or two and lots of notes to get the tire pressures and temps dialed in perfect. do 5 laps, come in to check and take notes, air the fronts down to be the same and do the same with the rear. go out and repreat hte process until everything evens out. after that dont touch your tire pressures. in the morning, look at the pressure in each tire. they will all be different but that is ok cuz when they heat up, they will be even. take notes on the weather so next time you run there with the same weather, you already know what to se the pressure at.
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1,315 Posts
Re: tire pressures
A guy taught me a trick when I was AutoXing...
Get a white chalk and mark a straight like from the side wall and into the tread of your tires.
After doing the first trial (AutoX), check and see how far the white chalk mark is left on the side wall. The ideal would be the white chalk disappear where the tire tread begins.
If the chalk mark disappeared all the way to the side wall (beyond the tread), you are way low on pressure)
If the chalk mark can still be seen on the tread, you are running high on pressure.
However, I think that trick is only good for autoX since you don't really heat up the tire that much, and you don't have much chance to test different settings. And that depends on the design of the tire too. The RE92 I used to have had tire tread way up into the side wall, and the Azenis I have right now only have about 1/2 inch of tread on the side wall.
Testing and keeping notes are still the best way to find the perfect pressures.
Correct me if I am wrong, please.
BTW, what kind of gauges do you guys use? I used to have a "Pen" style one and just found out it's so inaccurate. Wanted to get a Digital one, but don't know which one to get.
A guy taught me a trick when I was AutoXing...
Get a white chalk and mark a straight like from the side wall and into the tread of your tires.
After doing the first trial (AutoX), check and see how far the white chalk mark is left on the side wall. The ideal would be the white chalk disappear where the tire tread begins.
If the chalk mark disappeared all the way to the side wall (beyond the tread), you are way low on pressure)
If the chalk mark can still be seen on the tread, you are running high on pressure.
However, I think that trick is only good for autoX since you don't really heat up the tire that much, and you don't have much chance to test different settings. And that depends on the design of the tire too. The RE92 I used to have had tire tread way up into the side wall, and the Azenis I have right now only have about 1/2 inch of tread on the side wall.
Testing and keeping notes are still the best way to find the perfect pressures.
Correct me if I am wrong, please.
BTW, what kind of gauges do you guys use? I used to have a "Pen" style one and just found out it's so inaccurate. Wanted to get a Digital one, but don't know which one to get.
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4,232 Posts
Re: Re: tire pressures
The one I have I recieved as a gift. It has a round gauge with a red needle. You can use it a few different ways.alfa_chan said:
- You can fill up the tire real high and hold or screw the gauge onto the tire via its small hose. From there you can use its release valve button to bleed air.
- Use it as a traditional pen gauge style and just put it onto the tire stem briefly to get a reading. When you do this on mine the needle stay on the mark untill you depress the release valve. Once doing so you can hear the air pressure in the gauge release.
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I'll post some images of it when I get my digi cam back!
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Conspiracy Theory
Sniady you're killing me! I can totally relate to your Jedi mind tricks and beliefs.
I can't believe we have to pay 50 cents for f*****g air! Then again, my little ciggarette lighter powered compressor, took 10 minutes to get from 29 psi to 44 psi on my Accord.
I bought a cheapie digital gauge years ago at Fry's. I think it's accurate, therefore it _is_ accurate. I then just go by the psi recommendation on the sidewall. As I am a street driver . . for now.
Sniady you're killing me! I can totally relate to your Jedi mind tricks and beliefs.
I can't believe we have to pay 50 cents for f*****g air! Then again, my little ciggarette lighter powered compressor, took 10 minutes to get from 29 psi to 44 psi on my Accord.
I bought a cheapie digital gauge years ago at Fry's. I think it's accurate, therefore it _is_ accurate. I then just go by the psi recommendation on the sidewall. As I am a street driver . . for now.
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My last name is chEAP
I've a 12v that I bought in Target for $9.99. Works pretty good for me.
I found out those gauges in the gas station is at least +/- 10psi or worse. The one smestas mentioned is the one that I'm looking for.
But it would be better if there is an electronic one, with backlit and pressure release button.
I saw an article somewhere (about.com ??) and it says the most accurate ones are the electronic one. +/- 0.5 psi.
Still looking for that special gauge.
Too bad all the gas station in Pasadena either have the gauge missing, or I am too cheap to put in a quarter for air.Sniady said:
I've a 12v that I bought in Target for $9.99. Works pretty good for me.
I found out those gauges in the gas station is at least +/- 10psi or worse. The one smestas mentioned is the one that I'm looking for.
But it would be better if there is an electronic one, with backlit and pressure release button.
I saw an article somewhere (about.com ??) and it says the most accurate ones are the electronic one. +/- 0.5 psi.
Still looking for that special gauge.
I just moved in the Makati, Manila Philippines and surprisingly they have this automatic air pressure pump for FREE and FULL SERVICE!!! You just tell the attendant the psi you want in your tires and the attendant dials in the psi and the pump automatically stops or adjust your tire to the psi set.
Ex: If you asked for 30 psi but your tire(s) are greater than 30 psi the pump will automatically adjust your tire pressure for less or more to reach the 30 psi. AWESOME!!!
Ex: If you asked for 30 psi but your tire(s) are greater than 30 psi the pump will automatically adjust your tire pressure for less or more to reach the 30 psi. AWESOME!!!
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Random side note to the ancient thread:
It doesn't actually matter if a pressure gauge is accuate to the Nth degree, or even within a few pounds actually.
What is important is that the one you use is consistant and that you use that same one every time. Doing so establishs what pressures (according to the gauge) you run and can have repeatable results when adjusting. (until you lose/break/replace the gauge, then you get to start all over again with a different one)
I never trust the dial-it-in gauges at the gas stations as I've seen way too many that when set to say, 30psi, will put in 50psi or 20psi depending on weather conditions and if the thing is actually maintained regularly. (most aren't)
They're also kinda useless for cold inflation as driving to the garage warms the tires a bit, so whatever # you put in will be different once the tires cool which in turn blows the baseline pressures all to crap AFA a point of reference.
Of course if you're just looking to get air in the tires they're prolly OK, but if you're serious about tweaking pressure for handling then avoid that kind like the plauge.
It doesn't actually matter if a pressure gauge is accuate to the Nth degree, or even within a few pounds actually.
What is important is that the one you use is consistant and that you use that same one every time. Doing so establishs what pressures (according to the gauge) you run and can have repeatable results when adjusting. (until you lose/break/replace the gauge, then you get to start all over again with a different one)
I never trust the dial-it-in gauges at the gas stations as I've seen way too many that when set to say, 30psi, will put in 50psi or 20psi depending on weather conditions and if the thing is actually maintained regularly. (most aren't)
They're also kinda useless for cold inflation as driving to the garage warms the tires a bit, so whatever # you put in will be different once the tires cool which in turn blows the baseline pressures all to crap AFA a point of reference.
Of course if you're just looking to get air in the tires they're prolly OK, but if you're serious about tweaking pressure for handling then avoid that kind like the plauge.
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I go with Darren on this one. With some serious vintage racing in both my old 275 GTB Ferrari with HARD Michelin tires, and the same with my Alfa with SOFT Bridgstones, I resorted to the days when I really (tried) to race. I would use a tire pyrometer (modern electric, digital, non-contact) and measure heat across the thread after some hard driving. The idea was to find a HOT pressure that caused even heat across the tread, WITHOUT the tread chunking, or tearing away in little pieces at the edges. THAT was my racing pressure. Letting things cool down, that happened to be 33 lbs front AND rear on the Ferrari, cold. The Alfa is different. I use that same pressure with the Ferrari on the street, though it is not ideal with a cold tire, or on a cool day. When hot, the Michelins seem to have maximum grip at this pressure, and do not come apart.
My gauge is an old racing DRAGER. I generally over inflate, and bleed down to my desired pressure. Both the Alfa and Ferrari use valve stem supports to avoid the valve stems flexing around from centrifugal force at speed. I use TUBES in my tubless tires on tube type rims. Tubes do cause the tires to run hotter than without, but wheel design, Minilite magnesium on the Alfa, and wire wheels on the Ferrari, both designed for tube type tires, makes good tubes a safety issue.
Well ... that was a LONG answer to a short question! I hope it helps, Simon. This is from my experience.
My gauge is an old racing DRAGER. I generally over inflate, and bleed down to my desired pressure. Both the Alfa and Ferrari use valve stem supports to avoid the valve stems flexing around from centrifugal force at speed. I use TUBES in my tubless tires on tube type rims. Tubes do cause the tires to run hotter than without, but wheel design, Minilite magnesium on the Alfa, and wire wheels on the Ferrari, both designed for tube type tires, makes good tubes a safety issue.
Well ... that was a LONG answer to a short question! I hope it helps, Simon. This is from my experience.
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Last track day I used 30 # front and rear on the Vredestein 155/80/15.
Handling was neutral and they didn't throw any tread.
Compared to tires on the other cars--the 155s seemed a little wider than the tires on my mountain bike.
Some six months ago there was a thread on tire gauges when I found some old-fashioned ones with a rubber surround. Can't remember the name, but the price was right.
When is the battery in a digital gauge going to fail?
Just received some vintage-looking steel valve caps. From:
-- EE -- Expedition Exchange Incorporated
Tried this and it is vague.
How I found them was to Google: Tire Valve Caps and up came valve-cap images
Handling was neutral and they didn't throw any tread.
Compared to tires on the other cars--the 155s seemed a little wider than the tires on my mountain bike.
Some six months ago there was a thread on tire gauges when I found some old-fashioned ones with a rubber surround. Can't remember the name, but the price was right.
When is the battery in a digital gauge going to fail?
Just received some vintage-looking steel valve caps. From:
-- EE -- Expedition Exchange Incorporated
Tried this and it is vague.
How I found them was to Google: Tire Valve Caps and up came valve-cap images
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4,324 Posts
32 lbs front and 30 lbs rear got me a even temps across the thread at the track with 205/50/15's Hooiser's .
I just recently bought a programmable Craftsman digital pressure gauge ($25) it has a large display that's easy to read, has a memory, light and a blead valve. I like the digital read out better then the dial or stick type gauges.
http://www.sears.com/shc/s/p_10153_...blockNo=9&blockType=G9&blockNo=9&blockType=G9
I just recently bought a programmable Craftsman digital pressure gauge ($25) it has a large display that's easy to read, has a memory, light and a blead valve. I like the digital read out better then the dial or stick type gauges.
http://www.sears.com/shc/s/p_10153_...blockNo=9&blockType=G9&blockNo=9&blockType=G9
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