N54 DCT w/M3 Conversion

aus335iguy

Colonel
Nov 18, 2017
2,071
716
0
Down under
Ride
335i DCT 2009
Since XHP doesn't support the e9x M3 dct for some reason, I assume it's fair to assume it doesn't work on cars with this swap?
Not yet is the answer. They do intend to expand into M territory however as soon as custom flashing becomes available all bets are off. The M3 is just a different TCU calibration of the same thing so...
 

derekgates

Lieutenant
Feb 23, 2018
727
344
0
NW FL
derekgates.us
Ride
2011 335is

Hey there. Sorry for being away for so long.


I have been absolutely cranking on this mod to the point that I have far too many pictures to show. I have the diff to reinstall and exhaust to hang. Will try to post with some information/pictures.


xHP DCT news caught me by surprise! It seems like it fixes most of the problems I originally had with the DCT and am kicking myself slightly for starting this M3 DCT swap... they refuse to support this setup which is a big bummer.
 

derekgates

Lieutenant
Feb 23, 2018
727
344
0
NW FL
derekgates.us
Ride
2011 335is
Alright so where I left off was being stuck with axles, bushings and no Ohlins wrenches. All of this has been resolved.

First up, the diff bushings...

My bushing kit didn't have a large enough cup for the rear bushing so I got creative with a 3" PVC coupler and a piece of wood:

IMG_2005.JPEG
IMG_2006.JPEG
IMG_2007.JPEG


I proceeded to clean up the diff and get closer to reinstallation time... The diff cleaned up well!


IMG_2029.JPEG
IMG_2030.JPEG



I got the Powerflex purple bushings in place and tackled getting the axles removed followed by installation of the M3 axles...

Getting the axles in was no joke. Passenger side went in with minimal dead blow hammering but the driver side was multiple days of beating them in with a wood block... I started with a dead blow but had to use a 5lb sledge. The axle eluded me for a couple weeks. Then I found out there was a tool to pull the axles into the hub!

IMG_2052.JPEG

IMG_2053.JPEG
IMG_2059.JPEG


Alright. Axles are in, bushings in place. Then came the diff itself!

IMG_2070.JPEG


Sketchiest install, ever. I was terrified this entire time and struggled struggle struggled to get the mounts to line up. What a freaking pain. Got everything torqued up which was another absolute nightmare.

I ran into plenty of issues with attaching the axles and realized I had the wrong distribution plate for the bolts on the drive shaft. I got those plates ordered and cleaned up the shaft itself:

IMG_2060.JPEG

IMG_2062.JPEG


Painted it to ensure it stayed in nice condition. Those welds are fantastic! Thank you @LMB335is for helping with the shaft shortening, such a great job.


IMG_2075.JPEG

IMG_2073.JPEG


Ohhhh yeah.


At this point I got the driveshaft plates in and got that installed.

IMG_2093.JPEG


Perfect length! Pain in the ass to torque but it's in!

Then I started with my diff lockdown kit that I had 'customized' for the 335i with M3 diff from vwetish on N54Tuning and to install the mount... the diff needs to be dropped.

😭

IMG_2098.JPEG
IMG_2099.JPEG



But... that's in now...

At this point I need to get the diff reinstalled and the exhaust hung. Then interior, coding, tire shredding!


Since I love pain, I also decided to redo my Ohlins setup with a rebuild from @[email protected] ... It seems out of scope for this thread, but I will say the quality of his work has blown me away and I found all sorts of problems with my original setup (including ripped AKG rear lower mounts). I can't wait to experience it rebuilt! I have pictures, if anyone is interested. :)
 

aus335iguy

Colonel
Nov 18, 2017
2,071
716
0
Down under
Ride
335i DCT 2009
@derekgates I think your car and all this work deserves its own thread !!!
also just because XHP doesn’t “support” something doesn’t mean that you won’t get use out of it. Custom flash files for hybrid N54/M3 cars will soon be a thing!
 
  • Like
Reactions: RSL

NoQuarter

Major
Nov 24, 2017
1,596
993
0
Indiana, USA
Ride
Z4 35is, 535xi, X5 35i
Is there a version of this where the M3 GWS can be used with the stock TCU flash?

I never tried anything in between - installed and flashed all in one go.
 

aus335iguy

Colonel
Nov 18, 2017
2,071
716
0
Down under
Ride
335i DCT 2009
Is there a version of this where the M3 GWS can be used with the stock TCU flash?

I never tried anything in between - installed and flashed all in one go.

Now that we can flash the TCU probably but someone will need to figure out a custom flash for it
 

derekgates

Lieutenant
Feb 23, 2018
727
344
0
NW FL
derekgates.us
Ride
2011 335is
meh, xHP is proving to be the fixes I wanted for my DCT... ability to prevent creeping forward, adjustment of launch control, behavior changes in D/S modes, ability to control 'slip' on launches, disable upshift in M, etc. Shift speeds are not a concern for me at all; the logic surrounding shifts/when to shift have driven me crazy since I purchased my 355is (eg; car likes to shift in the middle of turns or eagerly shifts towards gear 7)...

I'd love to use the adjustments/sliders coupled with the incredible hardware applied with the M3 swap. Maybe @WedgePerformance can help me with some of these goals. I've talked with him about the sensitivity tables that were recently discovered... wonder about TCU stuff.

bleh.
 

aus335iguy

Colonel
Nov 18, 2017
2,071
716
0
Down under
Ride
335i DCT 2009
meh, xHP is proving to be the fixes I wanted for my DCT... ability to prevent creeping forward, adjustment of launch control, behavior changes in D/S modes, ability to control 'slip' on launches, disable upshift in M, etc. Shift speeds are not a concern for me at all; the logic surrounding shifts/when to shift have driven me crazy since I purchased my 355is (eg; car likes to shift in the middle of turns or eagerly shifts towards gear 7)...

I'd love to use the adjustments/sliders coupled with the incredible hardware applied with the M3 swap. Maybe @WedgePerformance can help me with some of these goals. I've talked with him about the sensitivity tables that were recently discovered... wonder about TCU stuff.

bleh.
Same here. I think I’ll keep the M3 gear I have so far and just wait till the flash arrives. It’s the best of everything
 
  • Sad
Reactions: derekgates

aus335iguy

Colonel
Nov 18, 2017
2,071
716
0
Down under
Ride
335i DCT 2009
According to XHP Short shifting is because the shifts are based on actual throttle and some of the tunes we have tune the throttle in a negative way. Talk to your tuner about putting your throttle values closer/back to stock
 

derekgates

Lieutenant
Feb 23, 2018
727
344
0
NW FL
derekgates.us
Ride
2011 335is
I spent Saturday cranking on the mod. 9. hours.


Got diff reinstalled, lockdown connected and put in heat shields.

IMG_2112.JPEG
IMG_2116.JPEG



Prepped and installed exhaust... and car SAT ON WHEELS for the first time since December. Yay!

IMG_2113.JPEG
IMG_2121.jpeg

IMG_2127.JPEG

(the Ohlins recommended rear height is ... very tall....)


Now onto the GWS rewiring and software.... Had to review my notes from 2018 and the original PDF that @aus335iguy made!
IMG_2117.JPEG
IMG_2118.JPEG
IMG_2119.jpeg
1596403146646.png
 
Last edited:

derekgates

Lieutenant
Feb 23, 2018
727
344
0
NW FL
derekgates.us
Ride
2011 335is
Woo! Getting so close 🤩
Yeah! Just finished all of the coding and interior.

On Öhlins setup, talk to @[email protected] ... he knows more about the BMW setups that Öhlins does, honestly.

Looking good, Derek!

Filippo

Indeed. This is a 3DM setup now, but I went with Ohlins start setup. I haven’t had a chance to contact Barry since I ordered this months and months ago; first time it has been on suspension in quite some time!
 
  • Like
Reactions: aus335iguy

derekgates

Lieutenant
Feb 23, 2018
727
344
0
NW FL
derekgates.us
Ride
2011 335is
Got the interior buttoned up, went through the fun of VO resetting, coding, etc...

IMG_2132.JPEG
IMG_2133.JPEG
IMG_2135.JPEG
IMG_2137.JPEG




First time it has run in 9 months. Woo!


Unfortunately... there is a nasty vibration in front when I am turning and any sort of elevation. I pulled back into garage and inspected with wheel turned in both directions and can't find the issue. Car still 'clunks' at full lock/certain bumps. Was hoping that was fixed with suspension refresh... bummer.

Secondly there is a driveline vibration... I can't tell where the rubbing is. It isn't constant like brake shield so I am assuming it is the dreaded exhaust heat shield. :cry:
 
Last edited: