Let me preface this by saying I've been a member of the N54 community for 5+ years now. My first N54 powered car was a "Certified Pre-Owned" 2008 BMW 535i that I purchased with only around 50,000 miles on the odometer from Century BMW in South Carolina. For those interested, the car is currently still being driven daily with over 175,000 miles and running great with the original turbos. This served as a great foundation for learning the ropes of this platform and I very much enjoyed adding a plethora of bolt on parts as well as taking care of the maintenance myself. After 5 years of every day use and adding over 125,000 miles on the car myself, I began to seek a way to give the car a bit of a rest from the high amount of miles it was racking up; plus I had developed a distaste for the automatic transmission, heavy curb weight, and squishy suspension.
What I'd be looking at getting in trade-in value or private party sale with this many miles was minimal, so I just decided to keep the car and began looking for the car I'd been crushing on for the past 6 months: the E82 135i. I tried to be fair to other cars and investigate something that would fit my wants/needs, but the 135i always came out on top. For 3 months I scoured the country for one with exactly what I was looking for which included: 6-speed, completely stock, white black or silver exterior, HIDs, and less than 70,000 miles.
When the right car popped up, I quickly hopped on the seller’s asking price and made arrangements to make the 7-hour drive to Norfolk, Virginia to bring the car back home to North Carolina with me. The seller said all the right things, and the car was even in better condition than described. Bone stock, always warmed up properly before being pushed, maintained religiously, had already had some of the injectors and HPFP replaced under warranty, and as clean inside-and-out as an 8 year old car could be. 53,000 miles on the odometer and right in my price range too. Besides the very first time I got behind the wheel of my first E46 M3, I had never been so happy after purchasing a car. I smiled the entire drive back home as I got used to everything; especially the active steering and 6-speed gearbox. The 535i has since been inherited by my significant other who has retired the car to simply getting her to work and back, about a 10 mile round trip. We also use the car for road trips and simple errands on the weekends when the 135i doesn’t make sense. Here’s a shot right after I got the E82 back home and she was introduced to her big brother.
I wasted no time getting to the modding side of things. Since the 535i was going to spend the rest of its life being driven nice and easy, I started analyzing which parts I could swap over. I did not want to deal with the hassle of reinstalling the OEM down-pipes to the 535i, which meant I’d need to retain some type of tune to keep the service engine lights away. The FMIC had also been performing great and had taken some fabrication to install correctly on the E60 platform, so I decided to keep that. And lastly, the Fuel-It! Stage 2 LPFP was performing flawlessly and was installed initially to replace a failing OEM unit, so that would stay installed as well.
At that point, I began picking up some used parts including a cheap, older JB4 G4 with wiring harness. I swapped out the G5 ISO and Bluetooth connector from the 535i to the 135i and installed using the including wiring harness from the JB4 G4. I was able to tuck the JB4 itself deep into the ECU box so the lid could easily close without issue. Now both cars were running JB4 tunes, and although the 535i was equipped with a slightly outdated model, it still retained all the code reading and deleting functionality I was looking for.
After knocking the JB4 install out quickly, I was feeling ambitious about completing all the mods I had on hand which included this extensive to-do list: changing the oil, plugging the holes from the front license plate, swapping over the used BMS dual cone intakes from the 535i, installing an ER charge pipe with HKS BOV and a 7” VRSF FMIC I purchased used from the forums, a new RB PCV valve, new OEM spark plugs, BMS cowl filters, a BMS modified CDV, a BMS clutch stop, blackout grills, LUX H8 amber angel eye LED bulbs. If this sounds like a lot to install in one day, it was. Took me practically an entire day to get everything in, but surprisingly enough, caught almost no snags and was able to take my time and was able to triple check my work. The FMIC gives the front end an aggressive look, but by leaving the lower mesh installed, leaves a little to the imagination as well.
The charge pipe and HKS BOV were the first aftermarket parts to find their way on my car. I'd always been hesitant to run the HKS BOV, and even though I probably won't run it forever because of the aggressive sound, its hard to deny the fun factor at times.
I've always preferred the badge-less look, so it wasn't long before the fishing line and Goo-Gone were at it again.
After letting my hands and body heal over the next 5 days, I was back at it the next weekend installing a used set of BMS down-pipes and a new set of MMP stock location silicone inlets. Previous to taking on this install, I thought that installing down-pipes on the E60 535i was the hardest thing I’d put in by myself because of the tight clearances and awkward angles. Little did I know this would be a walk in the park compared to inlets. The strategic decision to install inlets and down-pipes at the same time was no accident and was done to avoid tearing the car apart twice. I would need to remove the OEM downpipes regardless to reach the rear inlet, so might as well upgrade them instead of putting the restrictive original pipes back in place.
I took my time removing the plastic under trays and OEM down-pipes, and besides one of the nuts/bolts connecting the down-pipes and midpipes shearing off and having to be cut, the disassembly was fairly simple. A few hours in and I was ready to tackle the removal of the front OEM inlet. The front inlet was easy enough to get out and I was even able to pull it out in one full piece by removing the radiator fan.
The MMP replacement was secured with no issues, cleared the front belts perfectly and was completed in less than an hour. At this point, I was feeling pretty confident. If you look deep enough at the engine bay from up top, you can make out the MMP logo on the inlet connecting to the snout of the front turbo.
I quickly moved to breaking the rear inlet mounting tabs loose, and made the cut at the bottom of the rear inlet so I could pull it out the top. While this wasn’t the easiest, another hour and it was complete. I was still confident and not sure why people had claimed having such difficulties doing this on jack stands.
So four hours from the start of the install, I was now looking at placing the rear inlet into place, and everything would be complete. After the first four hours were enjoyable, I spent the next four hours letting my little 135i beat the **** out of me. I bled, I perspired, and I cursed. I’ve had to call in reinforcements before due to time constraints or to help hold something heavy, but never have I had to call in reinforcements because I simply couldn’t get it done by myself. I reached a point where there was no option going forward without another pair of hands. Even after calling in a friend to pull from the bottom as I pushed from the top, we were barely able to get it through, and then spent the next 30 minutes or so getting the inlet on the turbo itself and secured properly. down-pipes went on with ease, but never fun dealing with those pesky v-band clamps. Exhausted and relieved doesn’t begin to explain the feeling of cranking up the car, hearing no strange noises, no service lights, and hearing the engine purr with a slightly deeper growl than before.
MMP inlets finally in place:
The next weekend, it was time to address the current suspension. While the M-Sport OEM setup on the 135i was a giant step up from the feel of my 535i, I still had desires to get rid of the wheel gap, stiffen the ride slightly, but nothing to adversely effect drivability on a daily basis. When Tire Rack put the combination of the Koni STR.T shocks and Eibach Pro-Kit on sale at a little over $500, I jumped on the opportunity to upgrade. I've swapped out a dozen or so suspensions on newer model BMWs, so the installation on the E82 wasn't too difficult.
Rear Koni shocks and Eibach Pro-Kit springs ready to be put in to place:
And installed:
One front spring/shock into place, and the other assembled:
The previous owner had ditched the original run-flat tires in exchange for some Michelin PSS in upgraded sizes. He'd obviously pushed the tires through the twisties on a few occasions as they had decent wear on the outer edge of the fronts. Before I knew it, the front tires were in dire need of replacing. This was an excuse to get the wheel setup I'd always been set on since first seeing them -- Apex ARC-8. As their stock was dwindling, I was able to pull the trigger on a set of anthracite ARC-8 wheels in 18x8.5 ET45 & 18x9.5 ET58 wrapped in a set of brand new 235/265 Hankook V12s.
The BMS wheel pin and lug tool are both really helpful, and certainly something I wanted to use when mounting up the new wheels for the first time.
I also threw on some cheap smoked side markers from DDM tuning -- $10 + $10 shipping.
I'm really loving the new look. The drop is perfect and the ride is fantastic. Obviously not a huge leap in improvement over the stock suspension, but the lower center of gravity and more rubber makes it feel light, nimble, and confident. The wheels and tires go great with the black exterior and really bring the car together. Here's a sneak peek of the new stance and appearance until I can find the time for a proper shoot.
I spent the new few weeks enjoying the glorious new sounds coming from the front and rear of the car, getting used to all the available power on tap, and doing plenty of "parking lot look backs" to admire the new suspension, wheels, and tires. I’m not one to fully push the limits of an engine, so on 93 pump gas, I was content with the 13psi on map 1 for the time being. The combination of the cowl filters, intakes, inlets, hard intercooler pipes, HKS BOV, and catless down-pipes made the car sound sensational, while the modified CDV and clutch stop helped out with getting the car to effortlessly engage into each gear.
But it wasn't long before the E85 station on my way to work started calling my name.
After thoroughly shaking down the car with all the new mods and making sure everything was working properly, I added 3 gallons of E85 to an empty tank, filled the rest up with 93 octane as I had done time and time before on my 535i, set the JB4 to Map 5 and gave it a whirl. I did a few quick pulls to let the ECU learn and on my third pull with this new mixture, a dreaded misfire reared its ugly head. At this point the problem was only surfacing at WOT and under boost and my first long indicated that I desperately needed a back end flash to get my trims in line. In addition to gathering the equipment to use the BB software to load a back end flash more suitable for E85 use, I also decided to purchase my second Fuel-It! product: a new build Stage 2 LPFP.
This would give me the flexibility of adding more E85 once I got things running right. As was my last install with a Fuel-It product, this one went about as smoothly as possible and only took a little over one hour. Hooking up my BT cable and flashing the 135i with the BMS E85 BEF took longer than the install of the pump when it was all said and done. I also took this opportunity to flash my 535i back to the OEM BIN seeing as how it wouldn't be seeing much E85 anymore. Once I had verified everything was flowing properly and the new BEF boost settings were working correctly, I switched to 4/2 on the JB4, added what I equated to be a full tank of E50 and switched to map 1, which would target 15psi. I immediately began having the same misfire issues as before, but unfortunately this time it seemed to be getting worse as I drove and was triggering a cylinder 6 misfire code that eventually wouldn’t go away. Eventually the car began to run on only 5 cylinders, all the while this is the only code that was being triggered.
Since the spark plugs had only a few hundred miles on them, I expected a failed coil to be the culprit. I made the decision to replace all six so I wouldn’t have to deal with the need to replace one by one at a later date. After installing the new coils, I fired the car up with the new coils installed and still the same symptoms. Poor idle, running on 5 cylinders, etc. At this point I was a bit discouraged. Despite all the aftermarket parts being installed correctly and functioning properly I did not have a functioning vehicle. Misfires are common with N54 engines, and I’ve had to deal with them before with the 535i, but I hadn’t really expected having to investigate injector problems so soon after purchasing the car (only 2500 miles so far); especially injectors that had supposedly already been replaced once. Following a deep dive into everything injectors about this car, I discovered I had a mixture of two 07 and four 08 index injectors. Cylinder 6 happened to be one of those 07 index injectors. At this point I was already annoyed, so I wanted to avoid having this headache in the future.
Six new index 12 injectors would hopefully solve my problem and keep me misfire free in the near future considering the car now has all new injectors, coil packs and plugs.
Everything all laid out after removing the old injectors and prior to putting in the new index 12s:
Following some time in map 4 to make sure everything was functioning properly, I filled up with a tank of E40, switched to map 1 at 15psi, found some open road with no traffic, and rolled into the throttle. Plenty of power, no misfire, and felt smooth as silk with the new back end flash. Map 2, E40 fuel, and my current mods brought about all I was looking for in my power output from my daily driver -- gobs of torque and horsepower, conservative boost levels, and sounded sensational, but still a few decibels too quiet for my desires. A log of the map 2 run confirmed that the car was running stellar. My fueling setup and current mods allow for running map 3 at 19psi, or even the race map at higher levels, but for now I'm looking for some dependability and longer life from my OEM turbochargers, so map 2 at 17psi running E40 fuel seems to be a nice balance for daily driving.
Now that the engine seemed to be healthy and running strong, I began looking at some other aspects of the car that I wanted to improve. The gear selection shift knob was swapped for the ZHP weighted version (had and loved this same knob in both of my E46 M3s) and the perforated leather emergency brake handle was upgraded to the OEM BMW Performance pearlescent version. I also added a bit of alcantara with the OEM BMW Performance performance shift knob boots for the shifter and emergency brake.
I also added a custom-fit black Canine Covers seat protector for the rear. The rear seat is way too small for most humans, but it's practically perfect for my border collie, Winston. This piece protects, covers everything, and is easily removable for washing.
He liked the 535i, but he loves the 135i.
Ever since I swapped the used dual cone filters from the 535i to the 135i, the dirty (even though they were clean) look had bothered me. I began researching for a filter colored similar to the amber output of the LUX angel eyes. What I found was that white, red, and black were about the only colors available. With the suggestions from another forum I took on the task of creating my own. A set of white BMS dual cone intakes, some Tangerine RIT liquid dye, and orange Green Filters oil resulted in the following look. Coupled with the Plasti-Dipped black ECU and brake covers, and rusty vacuum canister bracket, the engine bay is starting to come together nicely.
Stay tuned for more upgrades and maintenance related DIYs to come!