Solid subframe bushings with stock diff bushings

Bartledoo · 12-04-2017, 06:00 PM

Quote:

Originally Posted by buddalun

Would you have gone with OE diff bushings, if you were to do it again?

Nope still would've done the purple powerflex. I already broke one diff bolt, and the tradeoff is worth it to me. However, if there was a way to get rid of the extra drivetrain sound I'd like that too.

pbonsalb · 12-04-2017, 07:58 PM

There are what look like vibration absorbers screwed into subframes on some bmw models. Not sure if something like this would work on our cars.

Hujan · 12-13-2017, 05:31 PM

Small update: I added an M Factory CF driveshaft to the mix and now the clunking from going from park to reverse to first at parking lot speeds is completely gone. And what remained of the very, very faint diff whine I had after moving from delrin diff bushings to PowerFlex purple is the same if not even quieter.

Bottom line: For those thinking of doing the M Factory CF driveshaft, it won't introduce any additional noises if you have solid subframe and poly differential bushings. If anything, it quiets everything down even more.

roastbeef · 12-13-2017, 06:19 PM

Quote:

Originally Posted by Hujan

Small update: I added an M Factory CF driveshaft to the mix and now the clunking from going from park to reverse to first at parking lot speeds is completely gone. And what remained of the very, very faint diff whine I had after moving from delrin diff bushings to PowerFlex purple is the same if not even quieter.

Bottom line: For those thinking of doing the M Factory CF driveshaft, it won't introduce any additional noises if you have solid subframe and poly differential bushings. If anything, it quiets everything down even more.

Weird, I'm very clunky...

Side note, how do you like it? I feel like it's like a third step in improving "feel" after solid bushings.

pbonsalb · 12-13-2017, 06:35 PM

It’s light and hollow so it transmits clunks even more. I definitely hear it clunking. I do agree that it does not seem to make diff whine any worse.

roastbeef · 12-13-2017, 07:16 PM

Yea, no impact on diff whine.

Redd · 12-13-2017, 07:53 PM

Quote:

Originally Posted by Hujan

Bottom line: For those thinking of doing the M Factory CF driveshaft, it won't introduce any additional noises if you have solid subframe and poly differential bushings. If anything, it quiets everything down even more.

Where did you get your M Factory CF shaft? I've been chasing them for 2 months and they are all sold out with no new stock date.

roastbeef · 12-13-2017, 09:54 PM

Quote:

Originally Posted by Redd

Where did you get your M Factory CF shaft? I've been chasing them for 2 months and they are all sold out with no new stock date.

they had a hiccup in their production. a ton of people bought them in the group buy about this time last year, so i think one comes up for sale from time to time from someone who bought but didn't install for whatever reason.

Redd · 12-13-2017, 10:16 PM

Sigh was hoping Hujan found an unsold stash somewhere...

pbonsalb · 12-14-2017, 07:05 AM

I think their DS maker was selling to other companies so they got the flange maker, who is related to them, to stop supplying their DS maker. This stopped production and they are sourcing, or maybe have by now, a new DS maker.

I bought one on eBay that VAC was clearing out for $750. It was a risk because it was not clear whether it was a DSS shaft or the same one MFactory had sold. I definitely did not want the DSS shaft that does away with the Guibo and tends to vibrate since I have one of those on another car. Turned out to be the same as the MFactory shaft. I suspect MFactory will be back in production with a new shaft maker or even making its own shafts within 6 months. Their product is nice so I would wait.

rhyary · 12-14-2017, 07:24 AM

CF DS...
This is why I bought 2 :-)
One on the car, one is safefly tacked in the basement.

I am in purple diff bush, already ordered the solid rear bush from Rogue and it will be going in spring 2018 project.

There is a added noise from all the track mode, but it is not my dialy so I am ok with it. I would not do all the mods on a daily if you have more than 30 min commute.

I had 16 track days in 2017 and at NYST i dropped my time from 1:48 to 1:37.
1:37 is getting into pretty fast territory. I made many but usdual changes one at a time. Each mode made the car lighter and the handling crispier. With each mode, it moved it away from luxury sport car toward sport car. There is no free lunch and BMW engineers are not stupid. It really a matter of how you use your car and what makes you enjoy it. By making one mode at a time, i was able to feel the transfomation and the trade offs were highlighted.

pbonsalb · 12-14-2017, 08:31 AM

I wonder whether the new M3 with solid mounted subframe uses 2 front and one sponge covered solid rear bushing for the diff or has changed the diff mounting. The only concern to me is the diff whine and I don’t think the hardness of the subframe bushings affect it much if at all. It’s the hardness of the diff bushings that I would focus on for a daily driver.

12-04-2017, 07:58 PM	#24
pbonsalb Lieutenant General 5228 Rep 10,611 Posts Drives: 18 F90 M5, 99 E36 M3 Turbo Join Date: Feb 2011 Location: New England iTrader: (4)	There are what look like vibration absorbers screwed into subframes on some bmw models. Not sure if something like this would work on our cars.
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12-13-2017, 05:31 PM	#25
Hujan Brigadier General 569 Rep 3,742 Posts Drives: M3 Join Date: Apr 2013 Location: . iTrader: (16)	Small update: I added an M Factory CF driveshaft to the mix and now the clunking from going from park to reverse to first at parking lot speeds is completely gone. And what remained of the very, very faint diff whine I had after moving from delrin diff bushings to PowerFlex purple is the same if not even quieter. Bottom line: For those thinking of doing the M Factory CF driveshaft, it won't introduce any additional noises if you have solid subframe and poly differential bushings. If anything, it quiets everything down even more.
	Appreciate 0 Quote

12-13-2017, 06:35 PM	#27
pbonsalb Lieutenant General 5228 Rep 10,611 Posts Drives: 18 F90 M5, 99 E36 M3 Turbo Join Date: Feb 2011 Location: New England iTrader: (4)	It’s light and hollow so it transmits clunks even more. I definitely hear it clunking. I do agree that it does not seem to make diff whine any worse.
	Appreciate 0 Quote

12-13-2017, 07:16 PM	#28
roastbeef Lieutenant General 11585 Rep 12,725 Posts Drives: E92 M3 Join Date: Nov 2010 Location: Orange County, CA iTrader: (4)	Yea, no impact on diff whine. __________________ Instagram; @roastbeefmike
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12-13-2017, 10:16 PM	#31
Redd Brigadier General 3897 Rep 4,160 Posts Drives: 2010 BMW E92 M3 Dakar Edition Join Date: Jul 2015 Location: Malaysia iTrader: (0)	Sigh was hoping Hujan found an unsold stash somewhere...
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12-14-2017, 07:05 AM	#32
pbonsalb Lieutenant General 5228 Rep 10,611 Posts Drives: 18 F90 M5, 99 E36 M3 Turbo Join Date: Feb 2011 Location: New England iTrader: (4)	I think their DS maker was selling to other companies so they got the flange maker, who is related to them, to stop supplying their DS maker. This stopped production and they are sourcing, or maybe have by now, a new DS maker. I bought one on eBay that VAC was clearing out for $750. It was a risk because it was not clear whether it was a DSS shaft or the same one MFactory had sold. I definitely did not want the DSS shaft that does away with the Guibo and tends to vibrate since I have one of those on another car. Turned out to be the same as the MFactory shaft. I suspect MFactory will be back in production with a new shaft maker or even making its own shafts within 6 months. Their product is nice so I would wait.
	Appreciate 0 Quote

12-14-2017, 07:24 AM	#33
rhyary Colonel 1563 Rep 2,869 Posts Drives: 2013 M3 Join Date: May 2015 Location: Albany, NY iTrader: (0)	CF DS... This is why I bought 2 :-) One on the car, one is safefly tacked in the basement. I am in purple diff bush, already ordered the solid rear bush from Rogue and it will be going in spring 2018 project. There is a added noise from all the track mode, but it is not my dialy so I am ok with it. I would not do all the mods on a daily if you have more than 30 min commute. I had 16 track days in 2017 and at NYST i dropped my time from 1:48 to 1:37. 1:37 is getting into pretty fast territory. I made many but usdual changes one at a time. Each mode made the car lighter and the handling crispier. With each mode, it moved it away from luxury sport car toward sport car. There is no free lunch and BMW engineers are not stupid. It really a matter of how you use your car and what makes you enjoy it. By making one mode at a time, i was able to feel the transfomation and the trade offs were highlighted. Last edited by rhyary; 12-14-2017 at 07:29 AM..
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12-14-2017, 08:31 AM	#34
pbonsalb Lieutenant General 5228 Rep 10,611 Posts Drives: 18 F90 M5, 99 E36 M3 Turbo Join Date: Feb 2011 Location: New England iTrader: (4)	I wonder whether the new M3 with solid mounted subframe uses 2 front and one sponge covered solid rear bushing for the diff or has changed the diff mounting. The only concern to me is the diff whine and I don’t think the hardness of the subframe bushings affect it much if at all. It’s the hardness of the diff bushings that I would focus on for a daily driver.
	Appreciate 0 Quote