peterbigblock

I am about to embark on some motor- and transmission-mount upgrades (using liquid urethane 80A durometer) and all of the durometer research I did made me start to wonder: What's the durometer of the stock rubber in those mounts? And what's the durometer of the rubber in other stuff on my Porsche? If I replace my control arm bushes with urethane (as opposed to mono *****) -- urethane is WAY cheaper -- what's the durometer of the rubber bushes I'm replacing with, say, 95A urethane anyway?

So, I went onto eBay and bought a $40 digital durometer. Is it super-scientifically calibrated to be used on the space shuttle? I doubt it. Plus, there is no more space shuttle. It's from China, of course. But it is supposedly quite accurate (for my purposes) and now I can go around sussing out the hardness of every bushing, mount, isolator, grommet, etc. on the car. Hell, I can probably tell when my tires have heat cycled out by keeping an eye on the hardness of the rubber tread. Won't the guys in the paddock be jealous?

I am a total dork.

peterbigblock

By the way, I'm in Hawaii on vacation so it's 10:43pm here. Just so you didn't think I was posting at a quarter to four in the morning.

LuigiVampa

I just bought the Moroso digital durometer on a whim. Looking at some of the other durometer threads here it looks like a lot of people think durometers are akin to voodoo.

From what I read you have to take a base reading when the tire is new. The temperature of the tire is also key. Never take a reading from a hot tire when you have come off the track. Also looks like the ambient temperature can affect the reading as well. A tire sitting in the sun can have a different reading from a cold day. Also have to take readings in the same places.

This is what I gleaned from searching around RL and the internet. Odd to receive a product with no instructions.

Igooz

Did you buy a digital durometer or is that a digital durometer-meter?!

OK - let me get serious as I have some experience here...
a) Don't forget that many of today's motor mount or other bushings (depending on location) are actually variable rate durometer and not constant. So measuing the surface does not give you enough.
b) The same material can/will have variable durometer in the X, Y, or Z direction.
c) Temperature causes a huge rate change on the durometer and drives the rates down. And different material behave differently.
d) There is also the frequency response of the material that causes different results in a dynamic environment. For example, you can have material A with a lower static durometer reading but it actually gives better dynamic performace than material B...
e) Aging (time) significantly effects durometer...

*What are you tryiing to do maybe I can help you?*