Urethene motor mounts
 

Anyone have urethene motor mounts on their P5 to tame the engine bounce?

Keep it between the paint...

A service guy at my mazda dealership has them on his Protege sedan, and he recommended to not get them. I took a look at them with the car on, and it it makes the front bumper shake(vibrate). And on top of it a piece of it broke off! but maybe thats just his car:rolleyes:

I put in the front mount only so far (rear is a bitch to do). I find the shifting much tighter with them on, and really like them. THe annoying part is that it does add more vibration, but only at idle is it noticable. My tradeoff is that I will never put the rear ones on, as the front ones make things tighter with the vibration still livable. I think if you put both on, the rattle would be unbearable.
I can only think that the top part of the urethane broke off if he overtightened the bolt, as otherwise it should not happen. Anyways, the edges do nothing anyways, its the urethane in the center portion that do all the work.

I think he meant a piece of the front bumber broke off?

na, i meant a piece of the mount broke off. It was ok, but he still took it back to get another one.

but see, all you are doing is transfering the vibration from the motor which is built to withstand it, to the rest of the car. Now I know the iron blcok is more suited to withstand the shake rattle and roll than the plastic parts in the rest of the car.

I say wait for the Mazdaspeed to come out, and then get the motor mounts for one of them. They are supposed to be a lot better.

This is partially incorrect.
When you rev your engine, it "leans" or "flexes" due to the change in RPM. This is more apparent when looking at the engine from the side of the car (i.e. looking at the pulleys). Have a friend sit in the car and rev it up from idle and you'll notice the block sort of tip toward the firewall. Urethane mounts stiffen up the engine in relation to the frame so that the engine flex doesn't occur relative to the PPF and the frame of the vehicle. This will reduce wheelhop when the tires are spinning and generally shorten engine response time. As a side effect, the natural vibration of the engine is no longer isolated from the rest of the car.

isn't that what i said?? by "stiffining" the engine mounts you are not allowing the engine to lean or move as freely and will transfer the vibration to the rest of the car. This is in fact the reason the engine is mounted with a certain degree of play, otherwise the car ride would be too rough and would prolly make holding a cup of coffee in the cup holder rather interesting. Although-i can see the theraputic value of a full body massage.

to put it simply the technology of urethane mounts is basically for racing/pretty spirited driving and drivers that will accept the consequences for every little detail that will make the car faster, handle better, etc. it wasn't made for everyday "hold your cup of joe while you go to work kinda thing" that's why they use rubber and liquid filled motor mounts from the factory. hell, i've seen in japan another new technology of the various crazy ideas they have is a shock absorber type dampner that attaches one side to the engine and the other to the chassis.

that's not really new, either. they call it a torque strap, and i know that cars from at least the 70's used 'em to control engine movement. and yes, the whole reason for making the motor mounts soft is so that the car will be as confortable to drive as possible, to appeal to as many people as possible, to sell as many cars as possible. the best handling responsive car would have solid motor mounts, spherical bushings in the suspension, and no rubber any where except the tires. but then, granny won't buy one because it will cause her dentures to fall out.

I hate my motor mounts. That is the first mod I wanted to do to my car. The sloppiness, combined with the nonlinear throttle (the computer "blips" the throttle when you push on the gas, fooling you into thinking you have more power than you really do), makes it hell in first gear in a parking lot. Anyone seen any hard rubber motor mounts? They make 'em for VW's, as a compromise between pitifully-floppy rubber and shake-your-fillings-out urethane. Hm, maybe Mazdas aren't cool enough yet.

just replacing the front mount with the urethane one seems like a nice comprimise. it is easier to get to, also. the only drawback to that option from my view is this: they only sell them in pairs.