E90 335i Build

Buying a 16-year-old turbo BMW as an 18-year-old high school student was, on paper, a terrible decision.

In late December of 2022, I accidentally found a beautiful example of an E90 335i listed for sale at switchcars. As soon as I saw the listing I knew I had to find a way to buy the car.

Somehow, I was able to convince my mom, took out a loan, and purchased my 2008 Montego blue N54-powered E90 335i.

Since Purchasing the car in early January of 2023, I have completely transformed the car in appearance, power, and especially handling.

Mod List:

Power:

Custom intakes
VRSF Aluminum charge pipe
“Tial” blowoff valve
VRSF catless down pipes
VRSF 7.5” stepped intercooler
PE muffler mod
Resonators replaced with x-pipe
VRSF 2.5” silicone inlets
Oil catch can off pcv
Custom Walbro 535 bucketed fuel pump
ARCterminator active EKP cooler
MHD stage 2+ tune
XHP stage 3 trans tune
Updated vanos bearing ledge and seals
Turner Motorsports 95a motor Mounts
Rouge Engineering transmission mounts
JXB center support bearing

Suspension:

M3 tension struts
M3 front lower control arms
M3 rear guide rods
Fresh rear upper control arms
M3 RTABS
M3 rear lower control arm bushings
Turner Motorsport toe arms
Turner Motorsport solid subframe bushings
ECS tuning 95a poly diff bushings
BC Racing DS series coilovers
Fresh strut mounts

Brakes:

Rebuilt and powered coated stock calipers
Zimmerman rotors
Front Ferodo DS2500 pads
Rear EBC yellowstuff pads
All EBC bluestuff NDX pads
ECS tuning stainless brake lines
ECS tuning solid slide pin bushings
Custom brake ducting

Exterior:

Cs style carbon fiber trunk spoiler
M-tech front bumper
Lux angel eyes
Gloss black grilles and front splitters
Smoked sequential side markers
Aodhan ah-x wheels (getting a different set soon)
Rolled fenders to fit tires
50% tint on the front windows and 35% rest of the way around

Interior:

Custom suede headliner
Baesic performance suede pillars and visors
Custom suede and leather wrapped steering wheel
NRW v2 paddle shifters
Suede shifter and e-brake boot
Aluminum e-brake handle
Misc suede-wrapped trim
Every LED in all interior modules switched from amber to white
All screens converted from amber to white
Blue m button and start button
Custom radar detector hardwire setup with built-in flashing mute button

Other:

Team Mfactory helical LSD
E diff coded out
Optimized DSC coding
All braking assists coded out
Many other functions coded to work better than factory

The Build Process.

The build process here is NOT up to date, however the above mod list is. The work reflected below is a very small fraction of everything that has been done to the car to date.

First time seeing the car

Even though my mom wasn't fully on-board, I knew I was buying this car as soon as I saw it in person.

Completely stock engine bay

As far as I can tell, this is the only picture I have of the completely stock engine bay.

The car was certainly not perfect when I bought it. There was an obvious and very significant valve cover gasket leak, which I used to help bring down my price.

I tore into the valve cover over the first weekend that I owned the car. This was the scariest job I had done on a car at the time, and I learned tons while doing it.

Removing the valve cover on an n54 (a completely stock engine bay at that) requires the removal of the intermediate fuel rails, coil packs, coil and injector wiring, wiring rail, strut brace, engine cover, intakes, cowl, and numerous other small clips and connectors.

My first power mods

Autozone air filters with some custom adapers! While not the fanciest setup, I have been making great power on these intakes since they were installed over my first weekend of ownership

Intake valve cleaning

The N54 has a chronic issue with carbon buildup in the intake ports due to its direct fuel injection system. Buildup on the valves results in reduced volume and efficiency of airflow in to the cylinders

Fixing BMWs design flaws

BMW has a habbit of using plastic parts in curcial positions. When tuning the N54, I was able to increase boost pressure from 6psi stock to over 22psi. At nealy 4x the factory boost pressure, the plastic charge pipe is prone to exploding and leaving the car inopperable.

At this point, the car has the basic performance mods. I tuned the car through MHD and was making considerably more power than stock, however, I was not quite happy with the way the car looked.

Pictured here is the car in its completely stock exterior form. At this point, the weather was not great and I couldn't justify spending significant money on wheels, tires, bumpers, and other purely aesthetic modifications.