Fabman
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Spring rate multiplier.
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Tire falls off cliff
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Fabman
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Rate of growth with rise in temp.
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the "N" is for nitrogen, so what could possibly effect handling so bad that it needs to be kept track of?
come on..somebody besides Fabman!!
BTW you're getting warm
come on..somebody besides Fabman!!
BTW you're getting warm
Fabman
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effective spring rate multiplier.
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dood.. so close, but what that 15% refers to effects everything you've mentioned.. spring rate, roll out, growth..
Fabman
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so what am I missing?
Fabman
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Pressure increase with temp...didn't I mention that?
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How about, the one thing that can totally screw you over with setup, tire wear, handling and a multitude of other issues while the car is on track, but when the tire cools off coming down pit lane, everything will appear normal?
Go look at the graph I posted
Go look at the graph I posted
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Mad Hatter
Gotta go Faster
You mean.....
continuous physical force exerted on or against an object by something in contact with it?
continuous physical force exerted on or against an object by something in contact with it?
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Ok guys..
Obviously, the info on the tire is the distance around, which I used to keep track of, but radial tires are so consistent that it really is no longer necessary, they are almost always within an 1/8 of each other.
The wheel set that the tire is on, because wheels wear out
The set of tires, such as Sebring set 4
The " N" is that the tire has been filled with
But the 15%
It's the amount of relative humidity in the tire
Obviously, the info on the tire is the distance around, which I used to keep track of, but radial tires are so consistent that it really is no longer necessary, they are almost always within an 1/8 of each other.
The wheel set that the tire is on, because wheels wear out
The set of tires, such as Sebring set 4
The " N" is that the tire has been filled with
But the 15%
It's the amount of relative humidity in the tire
Mad Hatter
Gotta go Faster
With 15% Rel. Humidity, is the advantage of using Nitrogen worth it?
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Absolutely, 15% is the max allowed by me. That's my spec. You really cant get there, and have consistency by using air. Especially in Florida where humidity is around 90% every day.
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Hang on Bob, you're going to school
ChrisM
Mostly harmless.
The more I learn the less I know.
Fabman
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I actually was going to say that and a Customer walked in, I'm finally finished with his job and now and it looks like I missed the party. Oh well, it was fun. Always interesting when Blacksheep is involved.
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OK, Bob, Chris and Mad Hatter, here's the red meat.
Let's say you have a car, running on a (mostly) left turn road course, so the right sides are going to get hotter. Your tires are saying from between 180 to 230 on the pyrometer, it's a hot day (90 plus). So the car goes loose, but when you come into the pits the tires are all in their target pressures plus or minus .5psi.
You make a bunch of changes, the car starts tight, goes loose, so you head down the adjustment rabbit hole time and time again..
But what is really going on?
Well, at some threshold ..say 220 degrees, the water in the right rear tire is heating up at a faster rate (trying to turn to steam, which under pressure, it won't actually do) than the surrounding air, or nitrogen, whatever you happen to be using. This causes a massive increase in pressure, causing the car to go loose but... as the tire goes under 220 on the cool down lap and the drive through pit lane, the temperature goes down, with resulting pressure, and all is apparently normal in tire world. Leading you to make a bunch of unnecessary changes in what is, in reality, a great handling car.
Have I seen this? well sort of, I'm not sure anyone has actually seen it, but I'd bet a bunch of people have actually experienced it, and not known about it, and believe me, I have experienced it in the worst way at the worst time.
In any case 15% is my spec for humidity in tires, I will not run more than that.
For this reason I work through a proprietary method of removing water from the tire. There are several ways to do that for the local guy, the easiest and simplest is to just use several water filters in a row on your compressor when inflating the tires, that should be a decent way to control water coming out of the compressor. Along those lines, nitrogen is also pretty predictive when it come to expansion, but.. that doesn't guarantee that the nitrogen is not bad either, because people who half ass stuff are worldwide. So it pays to sample your tanks when you replace them. With regards to "dehumidified air" I've heard of it, supposedly seen example of it... and it is not below my spec.
So, with regard to the OP, there are a number of reasons that you may have experienced these issues, I will still put my money on an A7 in almost every application, but details count, and this is just another detail than can have extensive, and across the board results in your pressure management.
At Daytona last year the track and temp was hotter than usual, several teams had tires blown off their cars in the banking, I would put money that those tires had water in them.
Let's say you have a car, running on a (mostly) left turn road course, so the right sides are going to get hotter. Your tires are saying from between 180 to 230 on the pyrometer, it's a hot day (90 plus). So the car goes loose, but when you come into the pits the tires are all in their target pressures plus or minus .5psi.
You make a bunch of changes, the car starts tight, goes loose, so you head down the adjustment rabbit hole time and time again..
But what is really going on?
Well, at some threshold ..say 220 degrees, the water in the right rear tire is heating up at a faster rate (trying to turn to steam, which under pressure, it won't actually do) than the surrounding air, or nitrogen, whatever you happen to be using. This causes a massive increase in pressure, causing the car to go loose but... as the tire goes under 220 on the cool down lap and the drive through pit lane, the temperature goes down, with resulting pressure, and all is apparently normal in tire world. Leading you to make a bunch of unnecessary changes in what is, in reality, a great handling car.
Have I seen this? well sort of, I'm not sure anyone has actually seen it, but I'd bet a bunch of people have actually experienced it, and not known about it, and believe me, I have experienced it in the worst way at the worst time.
In any case 15% is my spec for humidity in tires, I will not run more than that.
For this reason I work through a proprietary method of removing water from the tire. There are several ways to do that for the local guy, the easiest and simplest is to just use several water filters in a row on your compressor when inflating the tires, that should be a decent way to control water coming out of the compressor. Along those lines, nitrogen is also pretty predictive when it come to expansion, but.. that doesn't guarantee that the nitrogen is not bad either, because people who half ass stuff are worldwide. So it pays to sample your tanks when you replace them. With regards to "dehumidified air" I've heard of it, supposedly seen example of it... and it is not below my spec.
So, with regard to the OP, there are a number of reasons that you may have experienced these issues, I will still put my money on an A7 in almost every application, but details count, and this is just another detail than can have extensive, and across the board results in your pressure management.
At Daytona last year the track and temp was hotter than usual, several teams had tires blown off their cars in the banking, I would put money that those tires had water in them.
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Mad Hatter
Gotta go Faster
Holy crap. even in our dry semi-arid region where we do most of our racing... things get pretty humid.
We race from March to Dec. Too bad its so hard to get decent Nitrogen... the ones I tried in performance shops had the same temp ranges as air. Maybe time to see if we can get better stuff.
We race from March to Dec. Too bad its so hard to get decent Nitrogen... the ones I tried in performance shops had the same temp ranges as air. Maybe time to see if we can get better stuff.
Fabman
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I get it from my welding gasses supplier. We use it in labs so it its very clean.
Mad Hatter
Gotta go Faster
Yes I was just thinking I might steal a cylinder from work and see how that does. I have about 6 big ones fulll of O2 sitting at home in case we had Covid during the peak and hospitals were maxed out.
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