We are in the process of fabricating the subframe for my 20b project. I want to replace the stock liquid filled 20b mounts with something shorter in height before going any further.

I spent the last hour searching through threads on upgrading the stock motor mounts, and am still unclear about what polyurethane grade AND tensile strength to use. For those that reply, please state the following measurements:

-Shore Grade (and what scale A or D is being used)
-Tensile Strength

Useful link on the subject:
https://www.rx7club.com/showthread.p...ht=motor+mount

 

80 Shore A is what most people use, which is great for a street driven 13b. Although, there are some people running 90 Shore A. This is just a little stiffer, and would be recommended for a high-horsepower application.

Use the higher tensile strength (I think I used somewhere around 6kpsi). This comes in black. The lower tensile strength urethane comes in Amber.

 

Thanks for the reply. That sounds similar to what I was looking at:

Part Number: 8695K653 $54.97 Each
Polyurethane Material Type: Polyurethane
Durometer Range: Hard
Actual Tensile Strength: 6,500 psi
Shore A: 80
Color: Black

I'm uncertain about the relationship (if any) between shore value and tnsile strength. For example, the following alternative has a lower tensile strength, but a higher shore value.

Durometer Range: Extra Hard
Actual Tensile Strength: 4,100 psi
Shore A: 90

However, the next example has a lower shore value and tensile strength than the first example.

Durometer Range: Medium Hard
Actual Tensile Strength: 2,400 psi
Shore A: 60

Therefore, I don't see the downside to getting the highest tensile strength possible for any given shore value -someone please chime in if there is one.