What Transmission Mounts to Match BW (Group N style) motor mounts?

[Special_K]

Closest match I can determine are the Revshift 80A based on info in our forum, but hoping as of late maybe there are new options I overlooked.


Car is dual duty but favors track at this point, for context I’ve got the BW (Group N style, for GT4 iirc) motor mounts, solid subframe bushings, Powerflex (purple) diff mounts, monoball FCA and looking to add the Mfactory CF driveshaft for this coming season.


Any of you guys with BW or similar motor mounts running an upgraded transmission mount you like and would recommend?

In researching it’s pretty empty between OE to aftermarket. First step up are those Revshifts at 80 durometer, but I’m thinking something more like 70-75A is a better fit to the BW motor mounts (if something like that exists )


Appreciate any input, cheers!

-Kk

[Redd]

The consensus is stock rubber trans mounts are the best for a street driven car. Anything harder and there is a lot of NVH. Rubber durometer is around 60-70A anyway. The trans mounts also seldom wear so I think they are not a highly stressed part unlike the motor mounts.

[Special_K]

Originally Posted by Redd

The consensus is stock rubber trans mounts are the best for a street driven car. Anything harder and there is a lot of NVH. Rubber durometer is around 60-70A anyway. The trans mounts also seldom wear so I think they are not a highly stressed part unlike the motor mounts.

Yup, that’s also what I read. But good thing is the labor involved is fairly minimal from what I’ve seen. So if I give the 80A a shot and NVH is too much at least it’s an easy swap back to OE.

Also, and I might be alone on this, I actually like the seat feel of the BW motor mounts…that type of NVH doesn’t bother me much and I prefer it to stock, even on street driving. Just feels like you’re more connected to car and intune with how the engine is performing, but it’s not for everyone. On the other hand, the NVH you get from upgrading certain suspension parts will bother me until I know it’s normal and nothing has failed.

Aaand….This is the point where I usually start asking myself why not trade in for a p-car which have dynamic motor and transmission mounts…but the E92 M3 and S65 are just too good to ever walk away from. I’ve seen the powerflex adjustable motor mounts which involve inserting/removing pins, but man….if we only had the “magnetorheological fluid” mounts like Porsche (and the EDC suspension) where you can adjust at the push of a button, that would be awesome

[powerbait]

I have the revshift black 80A paired with the BW motor mounts and prefer the feedback and light vibes that I get. The drivetrain feels more connected and there's nice clunk when you first shift into gear from neutral, like the car is ready for business. I also prefer that in my cars. I have an e90 that has all stock mounts and it's very numb and I have to try to drive it fast, it's like I don't intuitively know what the engine is doing, I hate it, but I'm trying my best to keep it mild.
Also, I wouldn't say the trans mounts are fairly unstressed. I had one shear in two and the other one about 3/4 torn through. This was with maybe 50k miles on a 2010 back in 2022. I'd had the BW mounts for maybe 10k at that point. I have no idea what mileage they actually sheared at. I just happened to notice while I was under the car prior track event. I think I was going to see if I could engineer a way to use the stiffer Rouge manual trans mounts, but the cross member won't allow it. Glad I discovered it though.

[Special_K]

Originally Posted by powerbait

I have the revshift black 80A paired with the BW motor mounts and prefer the feedback and light vibes that I get. The drivetrain feels more connected and there's nice clunk when you first shift into gear from neutral, like the car is ready for business. I also prefer that in my cars. I have an e90 that has all stock mounts and it's very numb and I have to try to drive it fast, it's like I don't intuitively know what the engine is doing, I hate it, but I'm trying my best to keep it mild.
Also, I wouldn't say the trans mounts are fairly unstressed. I had one shear in two and the other one about 3/4 torn through. This was with maybe 50k miles on a 2010 back in 2022. I'd had the BW mounts for maybe 10k at that point. I have no idea what mileage they actually sheared at. I just happened to notice while I was under the car prior track event. I think I was going to see if I could engineer a way to use the stiffer Rouge manual trans mounts, but the cross member won't allow it. Glad I discovered it though.

Dang! Looks like the OE tranny mounts are totally good till their not. Catastrophic failure. Were you missing shifts at the track before you replaced the tranny mounts?

I noticed I’d occasionally miss downshifts on track once my OEM motor mounts were toast, both were cracked and fluid leaked out. Noticeable difference when I went from failed OE to BWs. The 4-3 and 3-2 downshifts are so crisp and never miss…hard to explain that visceral gratification of a crisp 3-2 downshift and S65 throttle blip on a hot lap to those who haven’t tracked the car yet


For 80A looks like its Revshift or 034. If you’ve had good luck with the Revshifts that’s a point for them

**EDIT**
Not sure if I misread previously but the 034 street density are actually 70A:
https://www.034motorsport.com/street-density-transmission-mount-bmw-e9x-m3.html . Curious to know if anyone has run these with BW or similar engine mounts.

I don’t know much about 034 and looks like Revshift has a longer history making these parts. Even though they make a higher stiffness mount seems like Revshift has more experience as a manufacturer

[pirategenes]

Originally Posted by Special_K

Curious to know if anyone has run these with BW or similar engine mounts.

Yes, I have the 70A 034 street density transmission mounts on my 6MT and the BW engine mounts. Car is mostly for track and driving to/from events. I think the BW mounts made more of a shifting difference and increase in NVH compared to the 70A 034 street density trans mounts. I still have the occasional 3-2 mis-shift in one part of my home track, which is annoying, but it's better (much less frequent) than it used to be. Now I'm considering upping to the 80A Revshift trans mounts for, hopefully, even more precise 3-2 shifts.

Also a note of warning for something else you mentioned:
Powerflex has a revised front diff bushing mount with an additional washer that resolves the issue that it's prone to tear out. They replaced free for me since my driver side front diff purple mount tore apart in less than a year (~2k total miles and 11 track days). I'm upping all diff mounts to powerflex black while I'm in there replacing the purple. (Fingers crossed this is possible without disconnecting the driveshaft and axles, which will make the job quicker/easier)

[Redd]

Originally Posted by pirategenes

Also a note of warning for something else you mentioned:
Powerflex has a revised front diff bushing mount with an additional washer that resolves the issue that it's prone to tear out.

Interesting. When did PF make this revision? Not sure if my purple diff mounts had the washer or not.

[pirategenes]

Originally Posted by Redd

Interesting. When did PF make this revision? Not sure if my purple diff mounts had the washer or not.

Just became available a few months ago.

[Scrippy]

I have Revshift for both. It was stated that they don’t really wear and I agree. My trans bushings were 11 years old when I replaced them and they were 95% new IMO. The job is super easy as well. NVH isn’t really bad at all. It got rid of my high rev up shift squeak as well.

[Redd]

Originally Posted by pirategenes

Just became available a few months ago.

Thanks. Will monitor mine. PF gives a lifetime warranty anyway so I'm not too worried.

[maddmatth]

I have the 034 transmission mount in my DCT car. They're the same design as stock, just solid rubber instead of liquid -filled.

You can hear gear changes and clutch engagement at low speed (parking lots, coming to a stop) but once you get going there is nothing noticeable to me. I think it's the stiffer engine mounts that create that drive belt/pulley noises that I can here while driving, but it's not loud, just noticeable. For engine mounts I also have the 034 mounts which I think are about the same as the Bimmerworld ones.

[gtogorban]

Also looking to buy trans mounts, did you end up going with the 034? Car is street driven with occasional mountain and track days, I have Turner poly motor mounts. Should I go with the 034 70a or Revshift 80a? I can handle a little nvh but don’t want it to be unbearable because I drive a lottt