Cobb Rear Motor Mount for Fiesta ST - Installed Review

Discussion in 'Fiesta ST Chassis Upgrades' started by BlueBomber, Apr 29, 2014.

  1. BlueBomber

    BlueBomber Active Member

    Hey guys,


    I got around to installing my Cobb Rear Motor Mount for Fiesta ST - anyways install was surprisingly fast and easy. You need a 13mm, a short extension, ratchet and hammer.


    Just get the car elevated slightly, preferrably level - having four jackstands would be great here.


    [​IMG]


    Anyways - here are my impressions:


    Upside: In-gear or any time the car is moving, smooth as glass. Shifts feel more positive, handling is better because the motor's not jumping around the goddamned engine bay and in general, the car just feels "better" somehow.


    Downside: While there is no increase in vibration while moving, at idle there is a subtle vibration. Think of it as a gentle massage. XD


    Overall Conclusion:
    Thrilled I installed this, even with the increase in vibration ONLY at idle, it makes such an improvement in the car for the rest of the time you're driving it that it's absolutely worth the tradeoff.
    I can see why Ford didn't use a stiffer durometer bushing in the roll resistor in the first place but that sloppy bushing really hampers the car.

    If minor vibration at idle REALLY bothers you, maybe you might not want the RMM, but if you want your shifts to be nicer for you and your passengers, the RMM is the way to go.

    Best,
    Nick aka BlueBomber
     
    Last edited: May 5, 2014
    speedprotege, kamakazee and smatty like this.
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  3. mossdahaus

    mossdahaus Member

    I have a feeling that with some more time and miles, those vibes will be less. Most mounts I've had have a "break in" time.

    Thanks for the pictures and the review! This is definitely on my list now
     
  4. BlueBomber

    BlueBomber Active Member

    Note: A customer came by ModBargains this morning and we fitted the PowerFlex STREET bushings; customer reports it's way too stiff and is going to come back and get the Cobb one.

    I also wanted to let you guys know that I haven't gotten the car to do any of its usual wheelhop shenanigans since installing the mount last night.
     
  5. kamakazee

    kamakazee Active Member

    Nick, it was nice to finally meet you today. So the Delrin insert you guys installed turned out to be more than I bargained for. The vibration is pretty bad on initial take off and the NVH is similar to having an exhaust drone. I spoke to Jurrian and he will be setting aside a Cobb motor mount for me so I'll be seeing you soon. For race purposes, I could see that comfort is not a priority so the Delrin would be fine. In my case, it wasn't so. Appreciate the feedback on the Cobb unit!
     
    BlueBomber likes this.
  6. BlueBomber

    BlueBomber Active Member

    Thanks for coming by! I'm sorry the PowerFlex bushings were harder than we reckoned they'd be - come by and try out my car so you can get an idea of what it'll behave like with the Cobb RMM fitted. I think it's that Goldilocks "Just Right" firmness
     
  7. bobjob

    bobjob Active Member

    wow, how long did the install take? I can just go to the modbargains aoffice and buy a cobb mount and you guys will install it?
     
  8. BlueBomber

    BlueBomber Active Member

    If you bought the Cobb one, a good shop can have you in and out in under an hour. It's really easy. Doing it the Powerflex way will take a little longer, but even pressing out the bushings, in our case, were still done within an hour or so.

    For Fiesta ST specific questions and tech info I am always happy to help, I just personally don't deal with any parts sales myself or scheduling.

    It's kind of a bitch without a level way to jack up the car, but very doable to do yourself.

    Again, sum total of tools is a 13mm deep socket, a ratchet and 6" extension. oh, and a hammer.

    It's worth noting that our cars are MUCH easier to do this to than a Focus ST.
     
    Last edited: May 5, 2014
  9. ghostwhite

    ghostwhite Active Member

    Powerflex doesn't make a delrin insert. And there street inserts would be softer than a cob mount according to stiffness rating


    Sent from my iPhone using Tapatalk
     
  10. kamakazee

    kamakazee Active Member

    [Q"BlueBomber, post: 21203, member: 1240"]Note: A customer came by ModBargains this morning and we fitted the PowerFlex STREET bushings; customer reports it's way too stiff and is going to come back and get the Cobb one.

    I also wanted to let you guys know that I haven't gotten the car to do any of its usual wheelhop shenanigans since installing the mount last night.[/QUOTE]
    I apologize, I forgot to mention that the delrin insert was from 2Jracing, not powerflex. Nick, I trust your judgement in regards to the cobb mount so ill see you whenever it comes in.
     
  11. BlueBomber

    BlueBomber Active Member

    You'd think so, but that's not how it played out in real life. "It fit in CAD"

    Idling the vibration is definitely noticeable but then the tradeoff is any time the car is moving it's smooth.
     
  12. bobjob

    bobjob Active Member

    Thanks I'll wait a bit for the missing parts issue some are having to get fixed and probably make a trip to the OC on my day off.
     
  13. Fiat slayer

    Fiat slayer Member

    I apologize, I forgot to mention that the delrin insert was from 2Jracing, not powerflex. Nick, I trust your judgement in regards to the cobb mount so ill see you whenever it comes in.[/QUOTE]
    I have the powerflex ones in my car and from what I can tell so far they're not stiff
     
  14. speedprotege

    speedprotege Member

    Just installed mine, must have for me!
    Good review!
     
  15. BlueBomber

    BlueBomber Active Member

    I have the powerflex ones in my car and from what I can tell so far they're not stiff[/QUOTE]

    It could also be preference. You got Street durometer bushings right?

    BTW here is a sneak preview of the install how-to, I need to clean it up a bit more but this will give you a better idea of how to install this part.

     
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  16. Fiat slayer

    Fiat slayer Member

    They're yellow so I'm guessing street ones
     
  17. bobjob

    bobjob Active Member

    ok now i cant wait, Bluebomber you pushed me over the edge! Whenever modbargains get it in i'll drive in to get it installed then go to work.
     
  18. Max Archer

    Max Archer Member

    I think I'll have to try one of these soon. Cobb would be nice but my shop has a Powerflex account so I can probably get theirs cheap. Install sounds like a piece of cake considering I have a fully stocked race shop at my disposal - certainly much easier than the E46 motor mounts I just did on Monday.

    Sent from my SAMSUNG-SM-N900A using Tapatalk
     
  19. BlueBomber

    BlueBomber Active Member

    ah, the ones we put into the white FiST that the guy didn't like were Black Powerflexes.

    Wonder if black is race durometer or something?
     
  20. ghostwhite

    ghostwhite Active Member

    Black is race


    Sent from my iPhone using Tapatalk
     
  21. BlueBomber

    BlueBomber Active Member

    That would explain a LOT.
     

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