4,000 Miles with My Daily Driven Single Turbo N54 135i

chadillac2000

Corporal
Oct 26, 2017
233
254
0
NC
Ride
2008 BMW 135i
Two months ago today, I began tearing down my 135i in order to remove my failing stock turbos and convert the car to a single turbo using ACF's N54 kit. Three weeks later, working on and off during my spare time, the install was complete. Over the subsequent five weeks between that first fire up and now, I've racked up 3,750 miles of use, broken in the clutch fully, learned how to drive the car over again with all the new hardware, and had to iron out the inevitable kinks involved with a project of this magnitude.

Since I had some free time today, and won't have much in the foreseeable future, I took the opportunity to take advantage of the nice weather and perform my annual polish and wax. Even though this car is a daily in all sense of the word and has spent every day and night outdoors for over two years now, I still like to keep the exterior looking mint. And since I'm transitioning to shorter oil change intervals now that I only have one turbo, even though it had been less than 4,000 miles and only 5 weeks since the N54 had gotten some fresh Motul and a new Mann, it was also time to do my first oil change.

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I've already detailed the steps I use to paint correct and seal my car earlier in my build thread, but after buffing diligently for many hours, I had something to show for my hard work. Not too bad for now having over 106,000 miles on the odometer.

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After spending so much seat time in such a short time, and in my previously used "stream of consciousness" style, here are my thoughts on owning a single turbo N54 135i, and in particular the 6062 ball bearing PTE turbo using AC Fabrication's kit:

  • For the first two weeks of single turbo life, I was plagued by o2 sensor issues. I had purchased and installed ADV sensors specifically for this conversion, but for whatever reason, I could not get them to cooperate with my IJEOS ECU. After pulling my hair out over possible culprits, I finally installed a set of NTK o2 sensors and my problem was solved so I could start enjoying the car. Those NTK sensors haven't skipped a beat since.
  • The Spec Stage 2+ clutch proved problem free while breaking everything in, and it was quite easy to learn the new engagement points. In comparison with the OEM clutch, pedal pressure has increased slightly, and everything grabs a bit harder once it reaches the engagement point. All in all, I don't have many complaints about my clutch choice. The combination of the UCP, shifter mods, and lack of a CDV, make gear engagement buttery smooth.
  • The MFactory steel SMFW on the other hand, has been the aspect of this build I've been the least keen on. Using MHD to raise the idle of my car to 950 has kept the "marbles in a can" sound many describe at bay for the most part, but this can be still be heard slightly with the AC on or if RPMs dip while taking off from a stop in 1st gear. While this is very easy to live with, the noticeable NVH caused by the SMFW at low RPMs in first gear was somewhat disappointing and surprising. This gets worse after shifting into 2nd gear after the RPMs fall again and low throttle is applied. That NVH during low-speed driving has been my biggest gripe yet, but doesn't manage to ruin the entire driving experience. Hopefully in the future, we'll have an option to ditch the SMFW and high HP misfires.
  • I've closely monitored engine activity through the JB4 Mobile App, and shared a bunch of the logs I've collected across numerous forums to get feedback and make sure things were looking okay. I had intentions of running an ethanol blend for added safety and more power, but as I progressed the wastegate spring boost of 15psi up to map 2's 17psi, it wasn't long before I saw I was running out of fuel from the HPFP side on E30 fuel at 17psi. Since then, I've tapered back the fuel to E25 to take some stress of the HPFP, and opted to just daily drive on 15psi. For the time being, I'm content with running this low boost map, but more than likely I'll add one of the upcoming intake manifold upgrades with integrated port injection once I get bored at this power level. For the record, things feel far faster at 15psi through the 6062 than 20psi + inlets felt through the stock twins.
  • The Phoenix Race FMIC is pretty unbeatable it seems. I've yet to see a log where IAT hasn't went down during a pull. My VRSF 7" non-HD FMIC would result in a large increase over a multiple gear pull when I was FBO. I'm also enjoying the stealthy black finish I gave it before installing.
  • By pairing the same catless N54 midpipe with Vibrant resonators and MadDad Whisper axleback that I'd been using for a while now with all the new single turbo hardware, the exhaust note is much improved. At idle and during normal driving, things are very tame. But any heavy application of the throttle and all hell breaks loose. Airplane style spool up sounds, a terrific throaty growl out of the rear end, and external wastegate dumps that make me smile every time. Natural run over or "burble" isn't as audible as it was with the twin turbos; not sure of the cause of the reduction--I've never used the MHD option and don't intend to. The common comparison to the 2JZ exhaust note from single turbo N54s is not exaggerated, they certainly share similarities. For a daily driver, I wouldn't change a thing sound wise. Plus no there's no sound pollution from rattling wastegates, nor do I have to worry about there being any in the future.
  • On the topic of being a daily driver, switching to a single turbo has only seemed to improve overall functionality and fun. Since the conversion I've been averaging 21.9 miles per gallon on a variety of low percentage ethanol blends between E20-E40. Oil temperatures are consistently lower. The large amounts of smoke and terrible smells of burning oil I used to be embarrassed by regularly are a thing of the past. There are no lights on the dash, and no functions were lost during the conversion. Drivability with the BMS ST E85 TS THR BEF is even better than I thought it would be, and the cruise control feature is even smoother than it was with the OEM twin turbo configuration. Four days a week I take this car on a 3 hour round trip, and it hasn't hiccuped once. Earlier this week I drove the car for 7 hours straight in a variety of different driving conditions with nothing negative to note. I'm impressed.
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I need to pick up a GoPro in order to get some better in-car footage, but here's a quick video I was able to make this afternoon including some start up action, walk around, some idle/revs, as well as a quick pull at the end . I wanted to get some audio of the exhaust at full throttle, as well as the external wastegates, so please excuse the fact I had to use my front facing iPhone camera to do so.

 
Oct 27, 2016
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Loving the progress man. I too can agree an all the things you've noted from gas mileage, to exhaust tone, cruise control ( 80 mile commute to work daily) oil temps etc. All those have had a dramatic change for the better IMHO.
 

dyezak

Major
May 4, 2017
1,768
1,515
0
Plano TX
Ride
335is
I'm always impressed by your car. It's remarkable. But you should paint that little bracket that you use to relocate the coolant overflow...it kind of jumps out at you when you popped the hood.
 

chadillac2000

Corporal
Oct 26, 2017
233
254
0
NC
Ride
2008 BMW 135i
Good post. I also had problems with the ADV sensors on both my ST cars.

I'm pretty disappointed in the situation with the ADVs. I was excited about having a long term solution to the o2 sensor problems a lot of ST cars are plagued with, but no such luck. The NTKs seem to be holding up fine so far however.

Loving the progress man. I too can agree an all the things you've noted from gas mileage, to exhaust tone, cruise control ( 80 mile commute to work daily) oil temps etc. All those have had a dramatic change for the better IMHO.

Yes, those were all positive benefits that a lot of people don't mention when debating whether or not to go with a single setup.

I'm always impressed by your car. It's remarkable. But you should paint that little bracket that you use to relocate the coolant overflow...it kind of jumps out at you when you popped the hood.

Oh, and am I the only one who thinks the 135i is like a grown up E46?

Thanks my friend. Now that I have all the big things taken care of, I can start focusing on the little thing again. I have ambitions of going with a 335D coolant take in the future, so I may tackle paint matching a bunching of stuff at the same time if I'm feeling frisky.

My first BMW was an E46, so that would make sense as to why I was drawn back to the brand with the release of the E82.
 

suspenceful

700 HP Club (N54)
Aug 1, 2017
542
551
0
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2015 M3, 2008 135i, 2009 335i
Hey it's my twin!

Glad things are working out well for you Chad. Would you mind sharing a lot of you going WOT in 3rd and quickly shifting to 4th and carrying that out for at least a little bit? I want to see if your post shift timing looks anything like mine.
 
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chadillac2000

Corporal
Oct 26, 2017
233
254
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NC
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2008 BMW 135i
Hey it's my twin!

Glad things are working out well for you Chad. Would you mind sharing a lot of you going WOT in 3rd and quickly shifting to 4th and carrying that out for at least a little bit? I want to see if your post shift timing looks anything like mine.

Vehicle doppelgängers for sure! It's been soaking wet here since about an hour after I made that video, so haven't had a chance to have any fun yet, but next week I have plans of removing the clutch input wire, uploading that new bog shift fix FW, and posting some new logs. Glad to see that it seemed to help out your situation.

Look at that paint!

I'm glad I documented the silky smoothness because a) it's not easy getting it that way, and b) it's already dirty again. We've had 48 hours of heavy rain here in NC, but there's no rest for this non-garage queen.
 
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Dmak

Specialist
Nov 19, 2017
75
40
0
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09 bmw 135i
As for your clutch/flywheel noise. Do you still have stock or aftermarket transmission mounts? Is your clutch disc sprung?

Reasons i ask is because i just installed mfactory smfw with a 335is pressure plate and a ACT 6 puck sprung disc along with poly transmission mounts. The car sounded like 30 yr old rusted out pos inside. After some reading, i reinstalled my stock mounts in and all noise are gone. Also rised idle to 900rpm and gear rattle is minimal. I was suprese how much noise gets transfer into the cabin with the poly mounts..
 
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Feb 4, 2018
16
7
0
Ride
2009 bmw 335i 6mt E90
Had any issues with heat management with the ST kit? Yours looks clean as fuck in the engine bay. I just finished installing my Doc Racing kit. Waiting on a new suspension to come in but haven't been able to sit in traffic yet and burn anything up. Was Curious. Appreciate the Feedback
 
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chadillac2000

Corporal
Oct 26, 2017
233
254
0
NC
Ride
2008 BMW 135i
I appreciate the feedback and glad to read long drives aren't an issue in particular heat issues! The car sounds awesome! Nice job on the detailing of the car!

I certainly took a lot of precautions to avoid any future issues in general, but paid the most attention to heat control. Everything is sleeved properly, heat wrapped, or relocated. I also skipped all the tacky gold and silver reflective heat tape. I've been keeping an eye on everything very closely and haven't seen any signs of any type of deterioration of anything. Makes me believe all the heat issues with the top mounts are from not taking enough time to place barriers between heat sources and stuff you don't want get burned up, running larger turbos, or running poorly fitting kits.

I love the way everything sounds as well!

As for your clutch/flywheel noise. Do you still have stock or aftermarket transmission mounts? Is your clutch disc sprung?

Reasons i ask is because i just installed mfactory smfw with a 335is pressure plate and a ACT 6 puck sprung disc along with poly transmission mounts. The car sounded like 30 yr old rusted out pos inside. After some reading, i reinstalled my stock mounts in and all noise are gone. Also rised idle to 900rpm and gear rattle is minimal. I was suprese how much noise gets transfer into the cabin with the poly mounts..

About a year ago, when I was just FBO, I switched from the OEM transmission mounts to those from Rogue Engineering. At the time I was still on the stock DMFW, and experienced zero increase in NVH from the stock mounts. I've also heard that stiff trans mounts will cause that same type of NVH even on the stock DMFW, but since I didn't experience any when changing to the Rogue Engineering ones (barely stiffer than stock), I kept them on. Maybe one day in the future, when I'm underneath the car, I'll switch back to the OEM transmission mounts and see if that makes a difference.

This is the clutch I purchased, and I believe it's unsprung. From what I gathered it's the Spec Stage 2+ that you want to order if you're pairing it with the MFactory SMFW:

https://topgearsolutions.com/spec-s...-2016-bmw-135i-335i-435i-m235i-free-shipping/

Had any issues with heat management with the ST kit? Yours looks clean as fuck in the engine bay. I just finished installing my Doc Racing kit. Waiting on a new suspension to come in but haven't been able to sit in traffic yet and burn anything up. Was Curious. Appreciate the Feedback

No issues at all, but I took extra precautions. I rarely drive the car for less than an hour at a time, have driven the car daily since installing the kit in all kinds of weather, have put as many as 7 hours on the car in one single stretch, and have gotten stuck in traffic jams on the interstate with bumper to bumper traffic for 30+ minutes at a time and everything seems to be performing better than it was with the stock configuration. As I've mentioned, runs cooler, sounds better, more power, on and on.
 

doublespaces

General of the Army
Oct 18, 2016
8,943
4,150
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AZ
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2009 E93 335i
Definitely one of the cleaner top mount installs. Proper install is one thing but looking clean is much more difficult.
 
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veer90

Captain
Nov 16, 2016
1,000
763
25
West Nyack, NY
Ride
e90 335i 6MT
This is the clutch I purchased, and I believe it's unsprung. From what I gathered it's the Spec Stage 2+ that you want to order if you're pairing it with the MFactory SMFW:

https://topgearsolutions.com/spec-s...-2016-bmw-135i-335i-435i-m235i-free-shipping/

Yes it's unsprung. Sprung Spec clutch doesn't work with mfactory SMFW, only Spec's own SMFW.

FWIW they use the same picture of the sprung hub in all their listings regardless of what you actually get. A bit misleading if you ask me.
 

suspenceful

700 HP Club (N54)
Aug 1, 2017
542
551
0
Ride
2015 M3, 2008 135i, 2009 335i
Vehicle doppelgängers for sure! It's been soaking wet here since about an hour after I made that video, so haven't had a chance to have any fun yet, but next week I have plans of removing the clutch input wire, uploading that new bog shift fix FW, and posting some new logs. Glad to see that it seemed to help out your situation.

Just an FYI, because I know you do a lot of highway driving, unplugging the clutch wire will deactivate cruise control. Not sure if it's worth it for you. But either way, the fix is working well for me!
 
Oct 27, 2016
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Just an FYI, because I know you do a lot of highway driving, unplugging the clutch wire will deactivate cruise control. Not sure if it's worth it for you. But either way, the fix is working well for me!

I plug mine in for work day commutes, might install a switch though for now. We are still working on a solution, don't worry!
 

chadillac2000

Corporal
Oct 26, 2017
233
254
0
NC
Ride
2008 BMW 135i
Deactivating the cruise control, at least for how I use my car daily and for long periods, would not be acceptable at the moment. Then again at my power levels and that I usually shift around 6,500 RPM or so, I never really experience any shift bog, so I'll just keep things as-is until we can figure out a way to have no shift bog + cruise control! Thanks for heads up!