I made a gun thread so I figured why not make a car thread seeing we have an Automotive Discussion section and the guys in TS have been hearing bits and pieces from me when the topics comes up. My car is a 2007 BMW 335i. I got it in March of '07. I have since modified the hell out of it. She's my baby, my girl, well until I can find the right one
I have taken the utmost care for it, inside and out. It has Swissvax Shield sealant to protect the paint from Miami's harsh weather. The car came stock with 300hp and 300ft lbs (measured at the flywheel, as all manufacturers do). It came with a new fuel system called Direct Injection. Instead of injecting with an air mixture before the cylinder as in all port injection motors, direct injection injects the fuel into the cylinder, against the compression stroke. In order to do this the fuel must be injected at an extremely high pressure, at redline it's near 3500psi. It makes this kind of pressure mechanically (driven off the belt) and uses a low pressure fuel pump to supply it at a constant 72psi. It allows for a more even burn, as the fuel is perfectly accounted for and atomized each time. This is a blessing and a curse because it allows for extremely lean burns during cursing and upon initial load, near 16AFR. For those who don't know what the means it is less fuel burning, ie: better mileage. The problem lies in its novelty as well as other things. 'The more you add the more it tends to break.'
Getting less technical, it now has mid 400's at the wheel -whp- (add 15% for drivetrain loss in order to compare to flywheel hp) on pumpgas/water-methanol. On racegas it has over 500whp. This is due to a hybrid turbo upgrade which involves cutting away material from the exhaust housings of the stock exhaust manifolds (I-6, twin-turbo, two banks) then welding on a CNC'd piece that will accept a new, custom, larger chra. The compressor housing is also bored out to accept a larger compressor wheel. The car also has supporting mods including a new airbox and intercooler for the 50% increase in cfm.
I added handling mods including coil-overs and sway bars, front and rear, as well as a front engine strut bar.
The car is tuned using basically a Haltech board running what's called PROcede and controls boost through the wastegates with vacuum instead of the standard external wastegate boost. The tune is completely integrated into the car and all ECUs. It re-calibrates my oil temp and fuel level gauges on my dash to read instead AFR and Boost, respectively. My steering wheel is an upgrade for e9x models called the BMW Performance Steeringwheel which gives me all sorts of read-outs as it's hooked into the same CANbus the tune is. You swap between screens: I can read G forces, forward/backward and side/side; another reads oil temp/water temp; another is a 1/4th mile timer; and the last is a Lap Timer for when I track the car and want to compare my own times, hotlapping.
In order to combat Miami weather I use something called Water/Methanol. What it does is not only cool the intake charge, but also increase the octane. I have it injecting on the hot-side of the intercooler, post compressor (water does not compress) and in the charge pipe, near the Tial BOV. When water goes from a liquid to a gas it absorbs heat and going from 220psi in the line to the intake charge that's way hotter and moving fast it atomizes the mix, hitting the nozzle like a brick wall and cools the charge, but the methanol bumps up the octane as it is 116octane. It's a win-win situation, but you need to be careful with this additive as you need a safe way to tell your car to get less aggressive with the timing (boost is just a byproduct of the timing run) ie: tuning. What my car does is switch 'maps' if the 'Safe-Injection' sees an impedance of flow. Being an I-6 it is a torque beast, especially being twin turbo. Stock spool was fast, peak torque would arrive around 2500rpm. Because the upgrade is a Ceramic Ball-Bearing chra even though larger it has greater spooling characteristics. If it were steel, like stock, it would be spooling at 4000 but instead I have peak torque by 3000rpm, 500lb-ft worth. I also upgraded the oil cooler to handle the increased load. It came with an external thermostat which dropped the activation temp to 180F instead of the stock's 230F. Without further adieu here are the pictures:
Engineshot, semi recent (as you can see, stock oil thermostat/lines):
Badly taken pictures of the external thermostat and CNC'd distribution block, awesome braided lines:
Old engineshot without plastic engine cover:
Airbox up-close (yes, those are fine, metal filters):
Trunkshot, water/meth tank:
Car with old rims:
Hotchkiss under-brace:
KW v2 Suspension (brakes stock back then, can you believe it? both single piston calipers!):
Steeringwheel on temp screen, lower dash gauges showing now Boost on left (used to be fuel, each thin hash-mark is 1psi, the thicker ones are 5psi increments, so 0-20psi) and AFR on the right (oil temp, far left is 20:1 or engine braking/off throttle cruising, so 20:1 is far left, 15:1 is in the middle and 10:1 is far right) as shown, sitting pretty at ~stoich
Front BBK:
Rear BBK:
My tranny dropped, clutch upgrade, Spec Stage 2+:
Stock clutch:
The still-stock dual-mass flywheel:
A culprit found before it turned worse, rear main seal replacement:
Replacement aluminum bolts for the tranny:
Fully divorced exhaust (two banks), except for an X-pipe to reduce rasp/increase top-end flow... no cats nor resonators, 2 mufflers:
My tuner adjusting new actuators (which control the internal wastegate, a flapper):
Comparison of stock to upgraded turbine:
How they sit on the car:
Manifolds off:
Here is a sound clip of the exhaust note after the upgraded turbos:
Rear of Upgraded turbo:
Rapid prototype of stage 2 (will be billet aluminum) vs a cast (normal) stage 1:
Stock vs Stage 1 vs Stage 2:
Stage 1 vs Stage 2 closer (forget about the shiny, look at the blade length, the pitch, and also the hub diameter):
Initial testing/clear comparison, stock vs stage 1:
Stage1
Stock:
Stage 2 (billet compressor wheel upgrade to stage 1) is still currently alpha testing on ASR's own 1-series (same motor, the N54). I am part of the beta test and cannot wait. Expected gains (at least mathematically) of +60whp.
Car more recently, new rims (photoshoot for the wheel company, MORR, 60% off to let them use the advertisement without royalties
:
Feedback is appreciated.
EDIT: Thought I'd add in some stuff I left out/forgot. It also has an aftermarket rear differential, upgraded from a stock open diff to a LSD (limited-slip-differential). What that means to those of you who don't know is that it tries to drive both rear wheels instead of being a 'one-tire-frier' like an open differential is because an open diff sends all the torque to the wheel with the least grip/traction. How silly right? But it makes sense when you aren't putting enough power down to lose traction. An open diff is meant for turning as one wheel has to rotate at a different speed than the other in order to not hop the inside wheel on a turn.The stock diff has the crown gear welded instead of bolted to the diff, so it makes swapping one nearly impossible unless you swap the whole pumpkin. I am part of multiple car forums and I swapped the entire pumpkin/driveshaft assembly+Cash with a guy who was going in for lease return. Worked out very well, saved a ton of money. The way an LSD can function on a turn depends on the type of LSD and it can get very complicated. If anyone has interest though I'd be happy to explain at least how mine works.
(slightly dated pic)
