transmission mounts - Group N / revshift 80a

[DIXIE NORMUS]

Hey guys my e92s at 75k miles and getting ready to do a complete suspension/drivetrain overhaul (if my brothers mustang ever gets off the lift)

i just got DD so I'm looking to make my car a little more track oriented, but i still want to be able to enjoy on the weekends. So far my suspension has been pretty much stock aside from ohlins coil overs, but heres whats in the works:

-Vorshlag camber plates (bought used a while ago and it was missing some parts..never got around to it)
-GAS thrust arm monoballs
-BW performance engine mount
-TMS solid aluminium subframe bushings
-AKG 95a differential mount bushing
-MFactory carbon fiber driveshaft
(these last 2 might have been a little compulsive)
-BW trailing link bearing set
-BW rear camber arm bearing kit

Ill probably make a build thread down the line with some DIY's on the installs, but idk if i will be able to truly review anything due to everything going in at once which sucks.. i might just save the BW bearings for a later install so i can review those cause i haven't really seen much feedback on them.

anyway, reason I'm posting this is because I can't decide which transmission mounts to get. I'm looking for a bushing slightly stiffer than oem, but not solid. i think I've narrowed it down to 2 options;

Group N
https://www.ecstuning.com/b-genuine-.../22308321927n/

or

revshift 80a
https://www.revshift.com/product-p/ptm-e9xm.htm

Has anybody out there tried either of these? I've seen 1 (maybe 2?) comments on the revshift 80a producing way to much NVH, but i know NVH is very objective and would like a second opinion on that. I haven't heard any reviews or comments even regarding the group N trans mounts which surprised me.

What are you guys are running for your trans mounts and what your thoughts are on them.

-Grant

[pbonsalb]

I would be happy to sell you my Revshift 80A trans mounts. I ran them for about a year, probably 8k miles. My car is purely a street car and they added a little NVH that bothered me a little and I did not drive hard enough to notice any difference in performance. But if you feel new stock ones next to these you will immediately feel how squishy the stock ones are. In fact they are so squishy bmw has to build limiting blocks into them so their is a limit to how much they will move. Half whatever they cost new, and I’ll pay the shipping.

[slicer]

I have been curious about the GroupN mounts as well. I'm still running standard trans mounts but I've upgraded every bushing except for the trailing arms and trans bushings. I am sure I'll do both within the next 6 months. I'll be sure to share my findings

[///Mobbin]

I've done some experimenting with transmission mounts in the past and IMO unless your car is a dedicated track car it might be best to leave them alone (aside from refreshing with new OE mounts).

That said it's a fairly easy swap if you just want to try it out.

My experience with the AKG Poly 95A mounts is discussed in this thread on pages 4-5: LINK

And in case anyone is interested I'm re-selling the AKG transmission mounts I experimented with: LINK

[DIXIE NORMUS]

Originally Posted by pbonsalb

I would be happy to sell you my Revshift 80A trans mounts. I ran them for about a year, probably 8k miles. My car is purely a street car and they added a little NVH that bothered me a little and I did not drive hard enough to notice any difference in performance. But if you feel new stock ones next to these you will immediately feel how squishy the stock ones are. In fact they are so squishy bmw has to build limiting blocks into them so their is a limit to how much they will move. Half whatever they cost new, and I’ll pay the shipping.

Im waiting to hear back from a buddy at bmw to see if he might be able to get a deal on the group N's, but if not that sounds like a good deal. PM me your price

@///Mobbin those 95a sounds just a tad too rough for me lol

[pbonsalb]

They are $120 new plus shipping. I’d sell my 80A Revshift trans mounts with ~8k miles and 1 year use for $60 shipped.

[ebisu8]

I have the Group N ones and there was no increase in NVH. I added them after my Vibra-Technics race motor mounts. I always read horror stories about how much transmission mounts added NVH so I thought this was a good compromise.

[pbonsalb]

The Group N are still soft enough that BMW retains the limiting nub you find on stock mounts to limit movement. They are probably as far as you want to go on a street car. It could be that if you raise the idle speed to 850 rpm in the tune, there will be less noticeable NVH from Revshift or comparable 80A hardness mounts. Same goes for motor mounts - a little higher idle speed often makes any buzzing go away.

[ebisu8]

Do we know what stiffness of Group N vs stock? I searched but came up short.

[pbonsalb]

If I had to guess, I would say stock is 65-70 and Griup N is 70-75. But I am guessing. Stock is really soft. It is also a weird design. You could probably do some custom welding to allow use of a conventional hockey puck style mount and use one an aftermarket one for a 335, which used the same GS6-53 but with a bell housing having 6 cylinder bolt spacing.

[M3NACE90]

Originally Posted by DIXIE NORMUS

Hey guys my e92s at 75k miles and getting ready to do a complete suspension/drivetrain overhaul (if my brothers mustang ever gets off the lift)

i just got DD so I'm looking to make my car a little more track oriented, but i still want to be able to enjoy on the weekends. So far my suspension has been pretty much stock aside from ohlins coil overs, but heres whats in the works:

-Vorshlag camber plates (bought used a while ago and it was missing some parts..never got around to it)
-GAS thrust arm monoballs
-BW performance engine mount
-TMS solid aluminium subframe bushings
-AKG 95a differential mount bushing
-MFactory carbon fiber driveshaft
(these last 2 might have been a little compulsive)
-BW trailing link bearing set
-BW rear camber arm bearing kit

Ill probably make a build thread down the line with some DIY's on the installs, but idk if i will be able to truly review anything due to everything going in at once which sucks.. i might just save the BW bearings for a later install so i can review those cause i haven't really seen much feedback on them.

anyway, reason I'm posting this is because I can't decide which transmission mounts to get. I'm looking for a bushing slightly stiffer than oem, but not solid. i think I've narrowed it down to 2 options;

Group N
https://www.ecstuning.com/b-genuine-.../22308321927n/

or

revshift 80a
https://www.revshift.com/product-p/ptm-e9xm.htm

Has anybody out there tried either of these? I've seen 1 (maybe 2?) comments on the revshift 80a producing way to much NVH, but i know NVH is very objective and would like a second opinion on that. I haven't heard any reviews or comments even regarding the group N trans mounts which surprised me.

What are you guys are running for your trans mounts and what your thoughts are on them.

-Grant

did you end up going with the revshift 80a mounts? I just ordered an rtd shifter and looking for mounts to pair up with it, but I dont want a lot of added nvh.

[pbonsalb]

I sold my revshift 80a after a year but forget to who. Maybe he will read this and report on his experience. I would try the RTD with stock mounts first.

[DRLane]

Originally Posted by pbonsalb

I sold my revshift 80a after a year but forget to who. Maybe he will read this and report on his experience. I would try the RTD with stock mounts first.

I think it was me that bought them - I'm running Ron's SSK and strongly considering a CAE upgrade. I pulled the 80a out and put stock back in. For now I'd rather upgrade the motor mounts as even the 80a increased the NVH significantly. Might simply swap for track days.

[M43S7RO]

How would you describe the NVH of the 80a gearbox mounts? Is it whine? Do you feel it? I bought a pair during black friday to be put in whenever I get around to swapping bearings.

I have a race xpipe (no cats/resonators) paired w a Corsa and if its sound, I'd bet the exhaust will drown it out. NVH is so subjective and different from car to car from what I've gathered from reading peoples experience w other bushings. I run 500 lb springs front, 1k rear, solid subframe bushings and powerflex black on all of the other subframe bushings and frankly I love the direct feel, unbothered by the added connection to the road.

But if its a buzz, kinda like exhaust drone that you hear and feel, I think that would drive me nuts.

[pbonsalb]

I have a catless x pipe and Megan rear exhaust, 75D poly subframe and 95A diff bushings, but just H&R Sport springs, not that any of those mods have anything to do with vibration from stiffer transmission mounts. The loud exhaust does mask some of the diff whine, however.

[DRLane]

Originally Posted by M43S7RO

How would you describe the NVH of the 80a gearbox mounts? Is it whine? Do you feel it? I bought a pair during black friday to be put in whenever I get around to swapping bearings.

I have a race xpipe (no cats/resonators) paired w a Corsa and if its sound, I'd bet the exhaust will drown it out. NVH is so subjective and different from car to car from what I've gathered from reading peoples experience w other bushings. I run 500 lb springs front, 1k rear, solid subframe bushings and powerflex black on all of the other subframe bushings and frankly I love the direct feel, unbothered by the added connection to the road.

But if its a buzz, kinda like exhaust drone that you hear and feel, I think that would drive me nuts.

I first tried the 95a and it was insanely loud, pretty much starting around 2500 RPM. The 80a isn't bad at low speeds until you really went WOT. I hear a deep groan or grind noise from the transmission which is over bearing...

That said, it take 15-20 mins to swap them in or out. Give it a shot, drive around for a day and see what you think.

As a reference I have no qualms with most NVh and my m3 is far from the OEM luxury ride. Solid subframe, solid diff, race camber plates, 95a rear shock mounts, performance coilovers, 95a shifter bearing, and monoballs. Now a Harrop SC. I love the whine from the diff and the super charger. Just didn't like the groan of the transmission.

[pbonsalb]

I drove for about a year with the Revshift 80A, probably 8000 miles. If they had been insufferable I wound have changed them sooner. I just eventually decided they were not worthwhile to me. I don’t notice any improvement in the shifting I do, but maybe I would if it was a track car.

[Mr_Reeves]

I've just installed RevShift 80A along with RTD shifter. There is a tiny bit more transmission wine at motorway speeds but I'm not sure if that's down to the shifter or the gearbox mounts.

I already had vibrations at low speed due to the BW engine mounts so there's nothing additional in terms of vibration to what I already had.

Gearshift engagement is cleaner though and there feels like less slack in the drivetrain. Personally, if you are fitting a new shifter and you track your car then I would recommend them.