Jake's Epic BMW 135i Build Thread (5+ Years of Ownership)


700HP Club (N54)
Aug 1, 2017
First off, I'd like to point out that I'm a late-comer to SpoolStreet. I originally started this build thread on 1Addicts (E90Post). However, once I got heavy into the modifications, the interest dwindled over there. Different crowd. I think this is a much better forum for my current build.... jump to page 3 for my current updates.

Current modifications:




  • MMP Stage 3 twin turbos
  • JB4 G5 with custom map 6 @ 28psi
  • BMS Hybrid E85 PI backend flash via MHD
  • MMP aluminum relocation inlets
  • MMP silicone outlets
  • VRSF 7.5″ race intercooler
  • VRSF 3″ catless downpipes
  • VRSF charge pipe with TiAL blow off valve
  • Precision Raceworks Stage 3+ LPFP with upgraded fuel feed line
  • Precision Raceworks/MMP port injection kit
  • Burger Motorsports port injection controller
  • Burger Motorsports oil catch can
  • Burger Motorsports cowl filters
  • RB PCV
  • NGK 97506 2-step colder spark plugs
  • 3.5 bar TMAP sensor

  • SPEC Stage 3+ clutch
  • MFactory single-mass flywheel
  • Poly transmission mounts
  • BMW Performance short shift kit
  • Teflon shifter bushings
  • Burger Motorsports clutch stop
  • Clutch delay valve delete
  • No-lift-shift/2-step relay
  • Redline D4 ATF transmission fluid
  • Redline 75W90 rear differential fluid
Wheels, Suspension, Brakes:

  • APEX ARC-8 Anthracite wheels:
    • Front: 18×8.5″ +45
    • Rear: 18×9.5″ +62 with 10mm spacer
    • Front: 235/40/18 Michelin Pilot Super Sport (PSS) tires
    • Rear: 265/35/18 Michelin Pilot Super Sport (PSS) tires
  • Eibach Pro-Kit springs (~1″ drop front & rear)
  • APEX 75mm Stud Conversion Kit
  • StopTech drilled & slotted rotors
  • StopTech Sport pads

  • BMW Blackline LCI taillights
  • Rieger flat black rear diffuser
  • OMGSplitters front splitter with APR support rods
  • BMW Performance spoiler
  • BMW Performance black front grilles
  • LUX H8 160 7K angel eyes
  • Black & white BMW emblem overlays
  • Tinted windows (30% front, 15% rear)
  • Tinted side markers
  • LED license plate lights

  • ZHP shift knob
  • ///1M floor mats
  • LED interior, trunk, and glove box lights

I'll copy and paste each update in a post here below. Stay tuned for continued updates and let me know what you think! You can always check my website for major updates: www.my1series.com


After lusting over the BMW 1-series for 3 years, I was finally able to get one of my own. On March 13th, 2014 I brought home a 2008 135i from Holland, MI. I am the 3rd owner and bought it with 81,000 miles.


She was pretty dirty after the 6 hour trip back.

Knowing that I would be keeping this one for a while, I needed to make sure it had everything I wanted.

Black Sapphire Metallic, 6-speed
Black interior with aluminium glacier-silver trim
  • Sport Package
  • Cold Weather Package
  • Comfort Access
  • iDrive/Navigation
  • HiFi Professional Sound System (Logic7)
  • Rear parking sensors
  • No 135i badge from factory
  • Additional cup holder
  • Warning triangle & first aid kit
Modifications it came with:
  • BMW Performance short shift kit and knob
  • Custom stainless-steel axle-back exhaust
  • Riss Racing oil catch can
  • K&N drop in air filter
  • JB+ 20HP chip
  • Powdercoated black Style 264 wheels with 225/40/18 Blizzaks
  • Eibach Pro-Kit springs (1″ drop front and rear)
  • BMW Performance black front grilles
  • Black/white BMW emblem overlays
  • Carbon fiber wrapped interior trim
  • Tinted rear and side windows
  • Tinted side markers
Had my girlfriend drive so I could take a rolling shot:


Next to my 250whp Miata:


I plan to slowly build it to my liking and keep up on maintenance. It hasn't had a walnut blasting yet, so that's on the top of my list of things to do. And I need to get a set of summer wheels so I can get these winter tires off.



Stay tuned!
Last edited:


700HP Club (N54)
Aug 1, 2017

New wheels came in today!

My first round of parts for the car are a staggered set of ESM BBS LM replicas with Hankook Ventus V12 tires and APEX TPMS sensors.
  • Front: 18×8 ET 35 – 215/40/18
  • Rear: 18×9 ET 40 – 245/35/18








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700HP Club (N54)
Aug 1, 2017

Spent $275 and a trip to Chicago-area to get my intake valves walnut blasted at ASPEC tuning. I had a bit of a cold start misfire (only in freezing weather) that I hoped this would fix, but it didn't. Either way, it was money well spent.


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700HP Club (N54)
Aug 1, 2017

I spent $60 for 3 pulls during a dyno today to get baseline numbers. She put down 283whp and 292wtq with just a drop-in air filter and catback exhaust.




700HP Club (N54)
Aug 1, 2017

I ordered JB4 and the BMS clutch stop last week and got around to installing both this weekend. Very happy with both products! I even found a little surprise (old disabled pinned out JB3) while installing JB4 that you can read about on my blog, just click here.

Filled up with a mix of 93 octane and E85 and was amazed on map 5! There is no traction until 3rd gear...


If you're on the fence about purchasing JB4... just do it! So worth it.


700HP Club (N54)
Aug 1, 2017

Well... something came in the mail today :)


Of course I had to set it on the trunk to see how it'd look.


Let's get it installed...



Then I changed the oil with some Castrol Edge, fully synthetic 5W-30. I used an OEM BMW oil filter kit too.


Since I was already underneath the car, I figured I'd try removing the clutch delay valve. 30 minutes later it was out. Look at how restrictive this thing is!


As always, check www.My1Series.com for more pictures, details, and impressions. The first two posts include everything I did this weekend. One for the CDV delete and oil change, and another for the BMW Performance spoiler install.

Also, I scored a set of used VRSF downpipes for a good deal and will be buying the 255 inline fuel pump to run up to 100% E85. When I install those, I’ll add the BMS E85 race flash. Should put it 400whp/wtq.


Stay tuned!


700HP Club (N54)
Aug 1, 2017

I installed my ZHP shift knob today.

Before: worn BMW Performance shift knob


Oooo, what's this? Excuse the fingerprints all over the top.


And installed... still fingerprints.




700HP Club (N54)
Aug 1, 2017

I decided that I wanted to install the downpipes yesterday. On the forums, most people say that the install is a major pain-in-the-ass. They said that they would rather pay someone else do it if they ever had to do it again. So, I went into this expecting it to take a while...

Some friends and I grabbed gaskets from AutoZone, ordered pizza, and slowly got started around 1:45pm.


We were pretty lazy throughout the whole process. I ended up getting most of the bolts off, but one in particular was giving us trouble. It was in a really tight spot and we ended up rounding it off. We ended up having to torch the shit out of it and use an air chisel to snap off the stud/nut.


After we got that out of the way, we still needed to unbolt brackets, v-bands, four O2 sensors, and unhook the whole exhaust from the hangers. We even had to unbolt the steering rack and move it out of the way for more room. Maybe we should have started earlier?


Around 10:00pm we finally got the catted pipes out. I was hoping the car would be buttoned up and back on the road by this time. That was enough for the night, I decided that we would have to finish the next afternoon. I didn't really take any more pictures of the actually install process, but we finally got them in today!



Also, I don't have a picture of them, but I wet-sanded and polished my exhaust tips since we removed the exhaust. They were black and caked with crap. I always assumed my exhaust was some sort of custom setup but as I cleaned the tips they revealed a "Riss Racing" stamp. Sure enough, this thing has a $1300 3" catback exhaust!

I had a friend take some cell phone videos to capture the exhaust sound inside and outside of the car. Excuse my excitement as I grannyshift up the onramp, I've never lost traction in 3rd like that before. Also, I'm not sure why I sound like a boy going thru puberty right at the beginning of the video...

After this video I put bus lengths on a new Camaro a few times from 50-120mph as he tried messing around. I'll drop in the E85 fuel pump next weekend and reflash the ECU more aggressively. Can't wait to hit up the strip and get her on the dyno again.


700HP Club (N54)
Aug 1, 2017

I ordered Steve’s Walbro 255 inline fuel pump kit so I could run up to 100% E85 for more power. The factory LPFP could handle a smaller mix of E85, but it was maxed out at that. I met up with Bob for help with the install. He has installed the pump before and also has the flashing tools and software. We installed the pump this weekend and flashed the ECU with a free E85-specific flash that BMS offers.


First step: remove the fuel pump bucket from under the rear seats…


As you can see in the picture above, we unplugged the connections first. I didn’t take any pictures of the actual removal process. It’s fairly straightforward if you follow Steve’s instructions. Here it is, removed:


Once it was removed, we started flashing the car because that takes about an hour by itself anyways. This way we could assemble the inline pump while the flash was loading.


Here is what the fuel tank looks like without the pump and bucket:


Now it was time to assemble the Walbro 255 pump to the bucket.


Adding the Walbro 255 pump…


Ready to go back in!


Re-installation of the bucket was easy. At this point, the bummer boost application was done pulling my stock BIN. The BMS E85 flash only took about 15 minutes to load after that. To my understanding, the flash overwrites the DME values so JB4 no longer has to intercept them. However, JB4 still controls boost and has the fail-safe actions in place.

The flash that I loaded was specifically built to be used with anywhere from 50% to 100% E85. I started off with a 50% mix and logged a few pulls on map 5 (auto-tuning map). The difference in power was similar to that of the catless downpipes. I was hoping for more, but apparently my results were normal. The inline fuel pump is doing a great job and is no longer stressing the factory system whatsoever. Now I am able to hit an additional 2 lbs of boost with the added fuel.


The screenshot above is an overview of the log I did on map 5, just to show you the parameters I’m working with. I also tried a pull in map 7 (race map), but the boost couldn’t hit target, so the results were similar to that of map 5. I’m not necessarily disappointed in the BMS E85 flash, but I’m looking for something more aggressive. In other words, I’ll be getting a Wedge flash installed next weekend!



700HP Club (N54)
Aug 1, 2017

When I bought the car, it came with a Riss Racing oil catch can. Good news, right? Well, not so much. After realizing how small the lines were, I couldn’t stop thinking about it. Why wouldn’t they utilize the large lines that the stock PCV system had? Plus, it’s mounted on the hot side, right on top of the turbos! Definitely a re-branded eBay part.


Anyways, I bought a BMS OCC because it’s built from the ground up specifically for this car. It’s hoses exceed the OEM PCV piping in diameter and that flow rate is maintained throughout the entire catch can ensuring no excessive crankcase pressure buildup. Unlike the Riss Racing can, the BMS version is mounted on the cold side underneath the cowl for a stealthy look. Holding the two, the BMS oil catch can is the winner, hands down. Gotta love Terry’s products.


Much better. The hoses are nice and thick and you can’t even see it once the cowl is back on. Very happy with the upgrade.

Now that the car is running higher boost, I decided I should probably replace the OEM spark plugs. I went with NGK 5992 plugs because they run a step colder than stock and are gappable.


I visited Bob again because I wanted to test for boost leaks. Part of me was hoping we’d find a small leak somewhere so I could upgrade to a metal charge pipe with a blow-off-valve and a larger intercooler. We didn’t find any leaks, but I’ll still buy those parts sometime soon.

Bob also has the tools for flashing the DME. My first flash was the free BMS E85 flash. It was okay, but I didn’t notice much. I went back and had him load an E85 flash from Wedge. It was great. I ran it for a week or so, took some logs, sent them to Wedge, and he sent back another version of the flash. This time when I visited Bob, I had him load the new flash that Wedge created. On the way home, I pulled up to an E39 M5 on the highway. He toyed with me and once things cleared up, we were able to do a pull. I put bus lengths on him! I’m not sure if I should have expected more out of his 4.9L V8 or if my car is just fast. I plan on hitting up the drag strip next week.


700HP Club (N54)
Aug 1, 2017

Last week, I scored a used BMS Dual Cone Intake kit on 1Addicts for only $25 shipped! It was just too good of a price to pass up. When I opened the box, I found a pair of very dirty white filters. I regret not taking pictures of them because they almost looked black.

After soaking them with degreaser and rising them off, they looked brand new again! A couple minutes in the sun and they were dry. Then I grabbed a can of K&N filter oil and sprayed a nice coat on top. To my surprise, the oil was red! My precious white filters were no longer white! Oh well… they still look great.


BMS claims that these puppies add at least 15HP to the wheels. I’m not sure how accurate that is but the sound is intoxicating! I had no problems with the K&N panel filter in the OEM airbox, but I read that it can be restrictive at higher boost levels. For only $25, I couldn’t go wrong with these. A quick test run proved that the car pulls great and sounds much better. Plus, I like the look of these under the hood.



700HP Club (N54)
Aug 1, 2017

This car has been in need of a good detail and I finally got around to doing it. First I washed it with Meguiar’s Gold Class Shampoo, then went over the whole car with their Clay Bar Kit. I was surprised at the amount of crap the claybar took off. Then I used a high-speed corded drill with a velcro attachment for cutting, polishing, and waxing.

I started with Meguiar’s Ultimate Compound on a 6″ foam cutting pad from Harbor Freight. After going over a body panel, I would let it dry and then wipe it off with a microfiber cloth. Next, I used Meguiar’s Polishing Compound on a 6″ polishing foam pad, again wiping it off with a microfiber towel once finished. The last step was applying Meguiar’s Black Wax with a 6″ foam finishing pad. Obviously wiping the excess off with a microfiber cloth.

I took a picture before I started the cut/polish/wax process. Once I was finished, I took another picture to show the results. Keep in mind, the “before” picture is when the car was already washed and clean. The imperfections you see are all swirls or scratches, not dirt.

This animated GIF will switch between images. Click it for high-res.


In the two photos, you can see a lot of things in my garage reflecting off the paint. The two lines near the middle of the photos are power cords, not scratches. The lighter reflections above those are the power boxes on the light stands. All other bright imperfections are either lights on the ceiling, lights on the stands, or bright objects laying on the ground or on top of shelves. Obviously you can see the reflections of the yellow and red light stands themselves.

This was my first time doing any sort of paint-correction and I am very happy with the results. I briefly researched what products were best and read good things about the Meguiar’s line up and the Harbor Freight foam pads. Said and done, the whole process took about 10 hours. I even wetsanded a spot on the rear bumper to get rid of some weird hazing. I finished up by using trim restorer on the plastic grilles/diffuser, and tire shine on the tires. Well worth it to me.

I was able to remove about 95% of the imperfections from the paint with this process. The 5% of imperfections that remain are very hard to see unless you’re inspecting the car under harsh lighting. It just goes to show how awesome the car looks and feels now. Also, the photos capture the metallic flake. It is easy to see in person but hard to notice in most photos. Black Sapphire Metallic > Jet Black!
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700HP Club (N54)
Aug 1, 2017

I was initially planning on storing my 1-series over the winter months, but the unexpected always seems to happen. My winter beater decided to throw a rod about a week into driving it. Wisconsin was getting pounded with snow and I had no other choice than to buy a set of winter wheels and tires for this car.
I bought the following from TireRack for under $1,300 shipped:
I took advantage of the free mounting and balancing they offer when you buy a set of both wheels and tires. They arrived like this:


I quickly removed the summer wheels and installed this new winter set. My first impression of them was great. Quiet, smooth, and soft.

Once the snow starting falling, I put them to the test and they performed perfectly. Unless the snow is halfway up the front bumper, I have faith that this car could bring me anywhere!


The car was due for some maintenance so I spent a weekend tidying things up.
  • Returned to factory pump gas flash for winter season
  • Replaced broken hood latch and stretched hood cable
  • Oil change with Motul 8100 5W-30 and MANN oil filter kit
  • Replaced faulty front brake pad sensor
  • Installed missing jack pad (front, passenger side)
  • Replaced broken dome light bulb holder
After getting the car back on the road, it's performed flawlessly. The wheels are great and it purrs like a kitten.


700HP Club (N54)
Aug 1, 2017

I’ve always preferred the look of smoked tail lights, but oftentimes the results are unflattering. I didn’t want VHT Nightshade anywhere near my BMW. Then I found out that BMW sells OEM tinted LCI taillights overseas. The only reason they aren’t offered in America is because they aren’t DOT-approved. Half of my car is no longer DOT-approved, so I decided to order them anyways.

I got mine from individual-car-consulting (Germany) on eBay, but now they can be purchased in the U.S. from ECSTuning. After about 4 weeks, they finally arrived! I couldn’t wait to install them.


Taillights OFF – LCI Blacklines (left) vs. OEM pre-LCI (right)


Taillights ON – LCI Blacklines (left) vs. OEM pre-LCI (right)

The install was very straight forward and only took about 30 minutes from start-to-finish. The LCI Blacklines were actually brighter than my OEM taillights. I’m very happy with the purchase and believe they’ve transformed the rear-end of the car.


Click the link below to see more comparison pictures.


OEM pre-LCI – Taillights OFF


LCI Blacklines – Taillights OFF


OEM pre-LCI – Taillights ON


LCI Blacklines – Taillights ON


OEM pre-LCI – Taillights ON


LCI Blacklines – Taillights ON


700HP Club (N54)
Aug 1, 2017

It was just another day browsing 1Addicts when I stumbled upon a thread about custom front splitters by fmxomar. There was a ton of interest, but no one had installed one yet. For the price, I figured I’d pull the trigger on the front splitter and a set of side splitters.

I thought these two items would flow perfectly with the Rieger rear diffuser that I’ve had my eyes on. The parts arrived within a week and came with installation hardware, but no mounting holes. I guess that’s what a drill is for! First step: remove the front bumper.


I started off by clamping the splitter to the bottom of the bumper and then lined everything up. 9 holes later and it was attached. I still wanted to mount the OEM wheel wind deflectors, so I trimmed 1/2″ notches in the back of the splitter to make room.


Because both parts are plastic and the splitter wasn’t structurally mounted, I didn’t want to take the chance of it folding under at high speeds. So, I installed two APR support rods. It took a little courage to drill into a perfectly good front bumper, but it was a risk I was willing to take. I followed the center-flow design and made sure to use large washers on the back of the bumper. Everything was secure so I quickly re-mounted the front bumper. It is a very sturdy setup.


Overall, I am very satisfied with this splitter. I would not recommend mounting it without supporting rods, but feel free to do so at your own risk. Stay tuned for the side-skirt installation in about a month!




700HP Club (N54)
Aug 1, 2017

Why do cars still come with halogen headlights and crappy interior bulbs? It’s 2015, Xenons and LEDs should be standard issue, since the 1 series is pretty old – I decided to take it upon myself to upgrade the interior lights.

I finally ordered some LEDs from ECSTuning. They sell a full LED kit for the 135i, but it’s marked up an additional $15 for no reason. So, I bought everything individually to save some cash. (1) overhead kit, (1) glovebox bulb, and (1) trunk bulb for a total of $41.33 instead of $54.95… you’re welcome. Here are my results:


There were no instructions, but the install was pretty straight forward. The front dome lights were easier for me to get at by dropping the headliner. Simply unclip the visors, pop open the visor holders (not the swinging section) and unscrew the T27 screw. Once you remove this piece from each side, the headliner should droop down. Now you’ll be able to slide your hand in and remove the bulb holders. The rest of the lights just require popping a cover off and replacing the bulb.

After all of this, I performed the $2 DIY blow off valve mod for cool noises. With my exhaust, I can't hear much of a difference.


700HP Club (N54)
Aug 1, 2017

Update: I sold my BBS LM replica (ESM) wheels. I ended up getting a deal on a set of APEX AERO-7 wheels locally, so I bought them this weekend. I test-fitted them right away and decided I really didn't like them, whatsoever.


I took them off right away and listed them for sale. The wheels sold right away, but I still have like-new Nitto INVO tires and TPMS sensors for sale.

I found a set of wheels across the country on Craigslist and convinced the seller to ship them. So, I sent him money last night and hope to have them by this weekend or early next week!

Anyone think I made a mistake by selling the LM reps or APEX AERO-7s?


700HP Club (N54)
Aug 1, 2017

I recently purchased a 75mm Wheel Stud Conversion Kit from APEX Race Parts to go with my APEX ARC-8 wheels. I chose the kit with hex head studs and silver lug nuts.

This kit makes wheel changing much easier and allows you to use spacers without having to buy extended lug bolts.
As the weather has been getting warmer, I decided it was the perfect time to install them with my summer wheels. So, I documented the process to share!

Step #1 – Loosen all 5 lug bolts while the car is on the ground.


Step #2 – Jack up the car, take off lug bolts, remove the wheel.


Step #3 – Apply a drop or two of thread-locker onto the threads at the short end of the stud.


Step #4 – Screw in the stud until it is hand-tight. Repeat these two steps until all 5 bolts have been inserted.


Step #5 – I bought the hex head stud kit, which accepts a 5mm hex key. I slid my 5mm hex key into a 5mm socket and attached it to a torque wrench with an adapter. Set your torque wrench to 25 ft/lbsand tighten all 5 studs. (You will need to have a friend press down the brakes while you are tightening the front studs. The e-brake will hold the rears while you tighten them.)


Step #6 – Slide the wheel back on the studs. Make sure it is centered on the hub. Tighten the supplied lug nuts onto all 5 studs.


Step #7 – Lower the car onto the ground. Grab your torque wrench again and set it to 88 ft/lbs. If you did not use a spacer, you will need a deep 17mm socket. Tighten all 5 lug nuts.


Step #8 – Repeat these steps on the other 3 corners and enjoy!





700HP Club (N54)
Aug 1, 2017

A few weeks ago, I started to hear a squeaking noise under the hood. Here is what I found:

Serpentine belt started shredding, so I started replacing stuff. Ordered a new belt and tensioner, along with oil filter housing gaskets (#1 & #2) because mine were leaking.

Oil filter gaskets going in... what a mess.


I put everything back together and assumed all was good. Wrong. About 50 miles later, the belt started shredding again. This time it started wrapping around the alternator pulley and burnt up the backside of the brand new tensioner pulleys.



Something was clearly causing the problem. Unsure where to start, I looked at the alternator because the belt wrapped around that specific pulley. The alternator pulley has a sprag clutch inside that allows it to spin one way, but not the other. This video shows how to test yours. After watching the video, I went out and tested mine. I carefully lodged a screwdriver into the fan to lock it from spinning:


Once the alternator was locked, I tried spinning the pulley by hand in either direction. It was seized and would not move. So, I assumed that was the problem. This time I ordered another new belt, tensioner, as well as an upper idler pulley, a lower idler pulley, an alternator pulley, and an alternator pulley removal tool.

All of the parts arrived and we installed everything for a second time. The new alternator pulley spun smoothly in one direction as it was supposed to. I thought everything went great and drove the car around for 2 days until the belt shredded AGAIN! This time the belt started tearing and worked itself off of the pulleys. I was shocked.


I went online and starting reading up on the repeating issue. I saw a lot of discussion about the power steering (PS) pump pulley coming into contact with the subframe. The pulley would hit the subframe and shred the belt or break the pulley. This was caused by worn motor mounts, allowing the motor to flex and sag when accelerating.

However, this issue only affected N54 cars produced up until 04/2008. Apparently BMW addressed the issue at that point. My car was built in 08/2008 so I didn’t think it was my issue, but I took a look anyways. While underneath the car, I noticed that this was NOT my issue. My PS pulley was NOT coming in contact with the subframe. But upon further inspection, this is what I noticed:

1 of my PS pump bolts was missing and the other 2 were loose! This is not on the pulley, but on the pump itself. After doing a little more research, a few others reported the same thing. Maybe it’s because the bolts are attached to the oil pan, become coated in oil, and eventually work themselves loose… I’m not sure.

Either way, I removed the 2 loose bolts and found another bolt that fit perfectly in the missing slot. I added a drop of thread-locker to each bolt and reinserted them. I couldn’t find the torque specs, but I torqued them down to 40 ft/lbs.

This time around the tensioner and all pulleys were still in good shape, so I just bought another belt (for the 3rd time). I installed the belt and everything has been running smooth for over 5,000 miles now.

Important Notes:
  • Check all pulleys the first time around! Make sure there is no play or movement in any of them. They should all spin freely.
  • If your N54 was produced before 04/2008, check to see if your PS pulley is coming in contact with your subframe. I’ve read that you can install 335is motor mounts (passenger side, driver side) to fix the problem. You can also notch the subframe.
  • If your belt has started to shred, pull over immediately! If the belt works its way around the crankshaft pulley, it can break through the front main seal and even work its way into the timing belt. Best case scenario: the main seal needs to be replaced (oil leak). Even worse, the main seal continues to leak and you run the motor dry. Much worse, the belt causes the motor to jump timing and self-implode. No one wants that, so be sure to check behind the crankshaft pulley for belt fragments. If the belt wrapped around the backside of the pulley, remove it and carefully inspect the front main seal.


700HP Club (N54)
Aug 1, 2017

After adding my aggressive E85 flash last summer, the factory clutch started to slip. I decided it was time to upgrade so I could enjoy the car to it’s full potential this summer. I decided to go with the 335is/550i clutch upgrade on ECSTuning.

It feels fantastic. The clutch pedal is slightly stiffer, but retains an OEM feel. The gear changes are nice and smooth with the new Redline fluid. Everything grabs like it should and I’m very satisfied with the new setup! I have over 5,000 hard miles on the setup and haven't had a single issue.


Here is a little more information about the process:

This clutch comes factory in the F10 550i, which puts down 443 tq and weighs a whopping 4552 lbs. DINAN doesn’t offer a clutch upgrade for their different stages of 550i’s, so apparently they feel that it is adequate. Their Stage 3 550i puts down 580 tq and they kept the factory clutch. Also, someone on the forums is using this clutch and claims that it is holding at over 620wtq on aftermarket turbos. To me, it sounds like the clutch is severely underrated.

My 135i won’t see more than 500 tq anytime soon (8/11/17 update: boy, was I wrong!). I’d guess that it is currently around 420whp/465wtq, but only weighs 3300 lbs!

I decided to give it a try. Here is my parts list from ECSTuning:
Total ECSTuning parts cost: $544.17

When replacing your clutch, I highly advise that you also replace the factory dual-mass flywheel (DMFW). The springs wear over time and will eventually let go. I chose to go with a lighter, single-mass flywheel (SMFW) from MFactory for $499.95 shipped. This brought my total parts cost to $1044.12, not bad.

Some pictures, from start to finish.



Still some life left on the friction disc, but some slipping spots with heat damage on the pressure plate. Everything else was ‘okay’. The new rear main seal was installed and the transmission was removed.




See those two bottles of Redline D4 ATF on the table? We drained the old fluid out and added about 1.5 quarts until it started overflowing. After that, the new clutch and flywheel were bolted on.



Lastly, everything goes back together in reverse order. Obviously I didn’t get pictures of everything during the install, but it all went together flawlessly. Big thanks to my buddy Kevin, who did an awesome job with the install. He took great care of the car!

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