I got my polyurethane from polyurethane products company, out of CA. Used 90A durometer, as that is what's generally used for motor mount applications.

 

3" dia x 1-5/16" 90A Polyurethane. Trued on a lathe, drilled 3/8" thru hole in the center. Endplates are 1/8" mild steel. Used grade 8 bolts, washers, lock washers, I believe the bolt was in the neighborhood of 2.5" long, but don't quote me, just measure yourself =)

any questions, ask away.

jesse

 

I'm going to use delrin for this, harder and longer lasting than poly but a little less vibration than aluminum.

 

It looks like all the aftermarket "upgrades" with urethane or hard rubber (hockey puck, etc.)use a single bolt that runs all the way through the mount. This sort of design will provide isolation only in compression -- in rebound it's shorted out by the bolt. Another concern is bolting through the urethane or rubber and expecting this soft joint to maintain clamp load. If you're gonna do this, I would recommend using a castle nut and cotter pin -- or at least a prevailing torque nut (nyloc or "jet nut").

If I remember correctly, the OEM mount is a totally isolated sandwich design that maintains isolation in compression and rebound. This is why it has studs at both ends. This seems to be a much better design. Does anybody know of a urethane mount that mimics the OEM design?

 

I like the competition motor mounts from Racing Beat.

 

I'm confused, you guys do know that mazdacomp and racing beat sell a stiffer mount right? I have them, works fine, as far as the height, they are the same because the are the same part number...

You can even get a matching tranny mount.

Alvin

 

How bad do the solid mounts vibrate in idle?
Anyone have any feedback on this?

 

Thanks for the lead. Since my team support number has expired at Mazda Motorsports, can you tell me how much their mounts are? I see the RB ones are $45 each. Is the construction the same?

 

RB ones fit and look like stock. The construction is the same. I swapped a couple sets in some 1st gens a couple months ago. They make a noticeable difference.

 

We are currently testing prototype mounts. Hope to have them available in a month. Our design is like stock where there are two apposing studs that are not joined inside the mount, for exactly the reasons you posted. I would have the say the mazda comp mounts are done this way as well.

-billy

 

Just checked, mazda comp is 42 dollars each. I just got confused by the long thread when this stuff is already availabe. P.S. I think the racing beat/mazdatrix/mazdacomp mounts are all from the same source.

Alvin