L98Terror

So I picked up this nifty Durometer today and I'm not sure what all these numbers mean but this is what I found.


100 Steel Hammer
96 Cooler lid
71 My F-150 Tires with 65k miles
66 My shaved 2003 RA1s with unknown heat cycles
65 My old NITTO Drag Radials
65 Set of R6s with unknown heat cycles (tires I'll race on this weekend)
65 My couple week old NT05s
62 Wife's Pirelli P6s
58 A6s about 6 heat cycles
56 4 year old MT Drag Radials (daily driven on my C4)
43 Bottom of my shoes
29 my thumb


Now I looked acrossed the rear of my A6 and found
Inside 55 Middle 60 Outside 63 what does that mean?

wallyman424

was that repeated with the same pattern on the other side?

also does the durometer have a margin of error?

pretty neat stuff.

geerookie

It's my understanding that the readings are only valid when the tires are at or near operating temps.
Their relative softness/hardness when cold may be an indication of how "sticky" they will be, but not very accurately.

L98Terror

The other side was 60 60 64 so similar, I'm sure there is a margin of error, I bet you need to do it in like 5 spots around the tire and take an average so like 15 measurements per tire, damn I need an intern

wallyman424

this racing business is serious aint it?

L98Terror

I'm not sure what I was thinking I have three **** on my shocks and have yet to turn one even a click, like I'm going to check tire hardness

wallyman424

what? you mean you don't adjust your tire pressure in .5psi increments depending on which way the wind is blowing that day?

TedDBere

Wow, a durameter makes me hard. I wonder how hard?

L98Terror

Last track event I was like what do we try to run these tires at hot again? I need to get a clip board and a piece of paper

ghoffman

Yep!

Han Solo

Mine measured 14. Getting old sux!

Kanmer

But getting old beats the alternative!

Use the durometer when your tires are warm. Now you also need to pick up a tire pyrometer. That will allow you to see how your alignment is acting on your tires. Blast into the pits from a hot lap, unstrap yourself, jump out of the car and quickly take 3 reading with the pyrometer on all 4 tires. Oh, and don't forget to write all the info down on that clipboard and paper. Better bring a pen to.

Bob

L98Terror

We already have one but keep being told that the tire pyrometer numbers are almost useless on a corvette and was advised to get a tire depth gauge and a durometer.

BTW I do take some notes.

gkmccready

Why are pyrometer readings useless if you have somebody in the hot pits take them? I can see it if you roll around for a cool down lap, or drive around the paddock, or ... they won't be 100% telling, of course, but combined with tire wear and handling characteristics?

L98Terror

I don't know but that is what Richard keeps telling me with the wide tires you can toss those numbers out, now that is how I set my pressures in the past so I'm again confused.

Falcon

I would imagine the durometer readings on a cold tire are good, but that reading must be compared to a relative tire. I'd guess getting the reading form a new A6, and then comparing later reading from the A6 so see if the rubber is getting harder. If it reads 45 when new and 65 later in its life, that'd be a good indication of when to expect to see it falling off significantly.

L98Terror

My plan really isn't to use it from brand to brand but for 1 set of A6s to another, and also try and figure out ideal cambers setting.

Falcon

Might work, but I'd guess pyrometer readings immediately on pit lane would be more meaningful for that.

L98Terror

Well even in early testing I'm getting different durometer reading accross the tire, it must mean something

JaxVette

Yeah, and just to make it a little more confusing, if you don't apply the durometer with the equal pressure and hold it for the same amount of time, you will get different readings. As you roll the footpad of the durometer onto the tire, take the reading as soon as the footpad is flat on the tire. If you leave it for a few seconds and then take the reading, the rubber will conform around the durometer probe and give you a false reading. If you press the durometer into the rubber with heavy pressure, you'll get one reading. If you lightly set the durometer on the tire, you'll get another reading. And then of course there's the hot and cold tire readings!!!!!

It's a good tool to use to track the degradation of the tires. That is, when all the grip is gone from your tires and the rear end of the car comes around and smacks you in the face, take a durometer reading. Then the next time you see that number, you'll know what's coming!!!!