Replaced rear motor mount ... rough ride

I had replaced the rear motor mount on my MS6 with the JB mount. 80 durometer. I had heard that the ride might be more rough but I am surprised just how much.

The engine is relatively loud and aggressive in the cabin. Certain RPMs (usually around 2000-2500) also vibrate the cabin.

How normal is this?

 

That's jbr for you

 

I'm running CS solid PMM and Torque Mount. I had to turn the idle up to 900-950 in order to smooth out vibrations inside the cabin

 

Will it smooth out at all over time?

Yikes I’d like this car to have good performance (relatively) but it’s still my daily driver. I don’t mind some aggressiveness but sometimes it’s too much. Idle has more vibration than my other cars but it’s fine. It’s mainly certain RPMs, and also 4th gear seems to be the worst—perhaps a combination of engine load and speed?

 

This will be a good time to have someone else drive it while you hop around inside the car and push on panels and trim pieces to find the source of the rattles. I have just become used to mine. I don't have torque steer anymore which is nice and rarely have passengers so no one complains.

 

Jbr is not a well designed product

 

Thanks for the tip. My complaint is that the entire car rumbles and vibrates a reasonable amount, and the engine noise in the cabin (but not outside) is a bit too loud at times. Maybe some people like that, which is fine.

Seems good build quality to me, but I wouldn’t know about design and won’t argue I’ll go ahead and order the Corksport mount. I hate spending more money on the car but if the JBR won’t smooth out then it might just be too aggressive for my taste. Maybe someone on the forums will buy it for a discounted price.

 

I mean their motto is embrace the vibes

 

It'll settle down after some time it's normal. If you want the best ride with upgraded mounts you want damond motorsports mounts. But they will still have a break in period.

Seriously man you need a build thread.

 

I had it for 90k trouble free miles. Yeah it settles. I did have all 3 and no issues too. Just vibss. I've had multiple other rear mounts too. Ain't no thing. Bushings wore out after 90k miles of abuse. Normal. And the bushings could have been replaced but I was offered a deal. I have Damond now and ifs a lot better but it's no prius.

 

+1 for Damond mounts.

 

Amusingly, I was driving my kids last night and told them I was planning on replacing the one motor mount and my son complained My daughter even said she didn’t mind it. Of course I had to ask them to repeat themselves a couple of times because I couldn’t hear them over the engine.

I’m guessing the Corksport has a more passive ride than the Diamond while still being tighter than OEM? Or is that not the case?

 

My corksport is a solid mount. No bushing at all. The torque mount is their stage 2 or whatever it's called. Basically damn near solid. I have a poly insert in my transmission mount. I have quite a bit of NVH but as I said kick your idle up to 900-950 and some of it should die down.

 

Damond has a new set of bushings that is not as "solid" that you can order as an option for less vibrations as well.

Go damond if you don't like it but it could take a few hundred miles of driving to break the mount in I don't even notice my Cobb one anymore

 

I have the CPE stg 2 mount and 100 years ago when I was almost stock it was my first "mod" It made no discernable difference in NVH. I would recommend it.

 

I’ve driven about 290 miles on the JBR. I realised today it’s actually more the sound I’m concerned about rather than the vibration. The engine sound reminds me of taking a vibrating tuning fork and touching it up against a wood table—the tone is amplified.

Are you all not fans of the Corksport mount? The Diamond looks a lot like the JBR in size, but it’s more forgiving? The CPE sounds very good in the description although it’s more expensive.

L337TurboZ, I’m impressed you’re using a solid mount I wonder what that’s like.

 

CPE stg 2 and CS Stg 2 are likely the most forgiving for NVH. JBR is the worst when it comes to NVH. Damond is legit as well but if you are sensitive to it stick to one of the stage 2 ones. If the RMM bothers you NEVER go aftermarket TMM or PMM lol. PMM is like you are riding inside the engine bay and it is so loud you feel like you are driving a race car when you are barely moving around town.

 

I have the CPE stage 2 as well. I'm going to switch mine out for a Damond to complete the trilogy.

 

I took this video today leaving work so you can have an idea of what I deal with during a cold start

 

Do you all have an aversion to the Corksport or just no experience with them? (Except for L337TurboZ, but I’m not talking about what he uses).

I have an order in progress with Corksport and it’d be easy to just add the mount to that order. But I have no feelings beyond that and if people here don’t recommend it then I’d reconsider.