Cobb RMM worn out?

[DanjenG60]

I own a 2014 with 32k miles. Had the car for about 2 months now and it came with cobb rmm already installed. I've since added an intake, depo IC, and stratified tune via the AP. When hard shifts from 1st to 2nd, which is a rare occasion, I'm getting that engine slap that I've read about that comes along with the stock mount. Is this normal? I don't feel any vibration etc but then again I don't know what the stock mount felt like. Don't know if I should look into another mount or not. Thanks for the help

 

[me32]

Pull it out and check it out?

 

[BRGT350]

if the engine is moving enough to make contact with the firewall, then something is very much wrong. Even with the stock mount, there is no way for the rubber bushing to compress enough to cause impact. Some early Focus ST's had an issue with the engine hitting the AC lines and that issue migrated incorrectly over to the Fiesta ST. The banging is from wheel hop and not the engine hitting anything. The hard shifting is causing the bushings to be wound up and then released, which the release of energy stored in the bushing induces wheel hop. A stiffer mount does help prevent this from happening by reducing the engine movement, but it can still happen since the control arm bushings are still rubber. Those will compress under acceleration, decompress under shifting, and then forced to recompress. This rapid change in deflection is a problem.

 

[DanjenG60]

Thanks for the response. I don't necessarily think it's hitting the firewall, but more or less was wondering if what I'm experiencing with the Cobb RMM was normal.

 

[BRGT350]

If the bushings are worn, you should be able to check with a flashlight and see if there is a section of urethane that is pushed out from the mount. That is a good indication that the bushing needs to be replaced. I have close to 30k miles on mine and it looks the same as the day I bought it, however, I am very gentle on shifts. I do my best to avoid any hard shifts.