How to Video: Upgrading the factory Engine Mount

[mendo]

Originally Posted by BobDiaz

In looking at the placement and design of the engine mount, to me it appears to be one of many key safety features.

If the smart is hit from behind hard enough, the engine will move forward. As it moves forward, the engine mount will rotate downward, pushing the motor under the car.



Once it moves past the 180 degree (straight down) position, the mount does move the engine upward, but look what it hits, a very solid "U" shaped steel bar. At that point, the weakest link fails; which happens to be the engine mount. If there's still any force from the impact, it appears that the engine will be pushed under the car.

I can't find any videos of a rear end test crash of the smart, not can I find any good still photos of a smart after rear end crash. So, I can't verify my best guess as to the safety function of the engine mount.



Bob Diaz

We went over this a while ago Bob,

if you take a look at the stock mount, it is completly captive. just has more play. if you were in a catastrophic event, the stock mount would not allow the motor to come loose, only to pivot, not too different from this. I have stressed the stock one to see how far it will go before the rubber tears, (in a vise) and the rubber does not fail even at the limits of the outer metal ring. So, the motor can only move so far then it thinks that it is solid. My guess from looking at it is that because it is at a slight angle when force is applied to the back (hit from behind) the motor will move downward until it hits the rear suspension, that will dissipate some energy. (crumple zone) I think any of these alternate mounts will allow the motor to move to the same place, the angles are all very, very close.

Bottom line is: yes, it is not stock. it will be a personal choice as to if you want to change it. I think it is safe, I run a modified mount.

if you want to get super critical, then maybe the stock big-giant exhaust is part of the crash worthiness. some people may not want to remove that. it is the size of some bumpers!!

[smartcar111]

In other news...

...I just ordered my BMS motor mount. I'm super happy with the free shipping! Can't wait for it to arrive

Also, Butch said that it could shave off a couple tenths of a second in the quarter mile. SM or Paul or anybody that owns a connector, is that your projected estimate performance wise for the mount? That stock really does rock back and fourth during acceleration and this mount is pretty solid so that is great.

[BARNEY O]

Originally Posted by smartcar111

In other news...

...I just ordered my BMS motor mount. I'm super happy with the free shipping! Can't wait for it to arrive

Also, Butch said that it could shave off a couple tenths of a second in the quarter mile. SM or Paul or anybody that owns a connector, is that your projected estimate performance wise for the mount? That stock really does rock back and fourth during acceleration and this mount is pretty solid so that is great.

Brett, can't give you a solid number as I didn't do a before and after at drag strip but you will feel a difference after you put it on. Street or strip!

Time to light up your electric supercharger thread, isn't it?

[smartcar111]

Haha I'm still deciding if I want to throw out the idea of the inline electric supercharger. Didn't throw it out totally, but still thinking about it.

We might rig something up one of these days just to see if we could get one or two psi, but college started and those weekday car projects are coming to an end and Butch is going to get his truck back so we are going to be working on that for the weekend projects.

For now though, your connector, window tint, and a Christmas gift of custom mounted Polk Audio speakers will suffice until next summer.

[nscaler]

Originally Posted by nscaler

Ordered mine. 80-85 lbs. torque according to the SM site.

Installed it two weeks ago. I was lucky as the second bolt went right in (I was dreading the prying part).
I do notice the vibration when stopped, but no vibration at any other time. I think the transmission does shift faster. Overall I am pleased. The video helped immensely!