Turbo M54B30 2003 Z4 Roadster (E85 chassis) Build (Bottom Mount with AC)

[VladBelsky]

Hi, all. Sharing my '03 Z4 3.0i bottom-mount turbo build.


Brief overview:


-MS43 ECU
-Has air conditioning
-CX racing GT35R journal bearing turbo
-E83 X3 2.0d Luk clutch disc (same friction material as the N63/E9X 335is clutch disc), eBay ClutchMax flywheel and pressure plate
-M50 intake manifold and fuel rail (return is welded up)
-Bosch 0280158123 630cc injectors
-B6 Audi S4 MAF sensor
-Precision turbo PW46 46mm wastegate
-EMUSA Intercooler 25in. (total length; core length is 18in.) x 12 x 3 (2.75in. core)


Turbo Specs (CX racing GT35R journal bearing)


• Compressor housing - .70 A/R
• Turbine housing - .63 A/R
• Compressor Wheel 61.3 /82 mm
• Turbine Wheel 62 /67.8 mm
• 4in. inlet and 2.5in outlet





Link to my wheelwell page with tons more photos and info:
https://wheelwell.com/vlad-belsky/2rj3/2003-bmw-z4

List of items purchased and costs for the build


Turbo Oil/Coolant feed
• Rally Road Feed line (bottom mount)- $33
• Rally Road Vanos bolt adapter to AN4 line- $33
• M14x1.5 to 3/8 barb (coolant to block)- $9
• 1/8 npt to 3/8 barb (coolant to lower rad hose)- $5
• 36 mm coupler with 1/8npt hole- $10
• Drain line (5/8 in pushlock hose and 3/4in heat shielding)- $20
• 5/8in weld-on aluminum bung for oil drain- $5
• Oil pan baffle kit and oil pan gasket- $204
• 10ft 3/8in ID ss braided teflon line- $40


Clutch
• E83 X3 2.0d Luk clutch disc (part # 21207553770) and
E60 550i pressure plate (from Luk kit with BMW part # 21207573789), ended up using only the disc- $340
•ClutchMax S52/M52 15lb chromoly flywheel (surface needs to be machined 0.020in to accomodate the E83 diesel disc) w performance pressure plate (70% more clamping load, from their stage 3 kit) - $240
• 22-spline clutch alignment tool - $8
• Pivot pin (brass) - $18


Intercooler
• 2.5in Pipe kit $72
• Intercooler $80
• Intercooler mounting materials - $20
• Extra 2.5in 90 elbow - $9


Fuel System
• Bosch 0280158123 630cc injectors - $250
• Injector spacers - $40
• Bosch 0261230191 MAP sensor - $40
• Deatschworks DW200 255lph fuel pump- $86


Exhaust
• Manifold ($140 including labor to machine it)
• VHT 2000F paint- $20
• Dump tube and downpipe starter fab + material - $140
• T304 stainless 3in V band clamps/flanges x 3 - $54
• 8FT 304 stainless 3in pipe - $60


Turbo
• Turbo - $300
• Rally road E46 turbo engine mount arm w FEBI 15786/274111 engine mount -$180
• Precision Turbo PW46 46mm Wastegate - $350
• TiAL-style (Tial BV50 replica) 50mm Blow Off Valve - $54
•-11lb spring for BOV - $15
•Genuine Tial O ring for BOV - $5


Air Intake for Turbo
• 4 in to 2.5 in 45 degree elbow/coupler - $10
• 2.5in inlet cone filter - $14


Gaskets/Misc
• Exhaust manifold gaskets (BMW part #11621728984)- $18
• Copper spray Permatex 80697 - $10
• M7 exhaust nuts part #11721437202- $10
• Engine/trans mounts - $45
• Spark plugs NGK BKR7E (set of 6) - $18


AEM Failsafe 30-4900 wideband/boost gauge- $300


Fabrication costs
• Oil pan modification labor- $100
• Fabrication labor for exhaust, charge piping, and air intake- $650


Total:
$4045 USD

[pbonsalb]

Nice job! Cleanly done. Reasonable cost. I did not read about a thicker headgasket or spacer or tuning for E85 so I assume the boost is pretty low, like maybe 10 psi.

[someguy2800]

very nice. I like the Z4 chassis

[VladBelsky]

Nice job! Cleanly done. Reasonable cost. I did not read about a thicker headgasket or spacer or tuning for E85 so I assume the boost is pretty low, like maybe 10 psi.

The engine is unopened and runs on 93 AKI. Wastegate is set to 7.5 psi, hits 7.25. If I hit my goal of 350whp once the new clutch is in and broken in, then I'm happy where I'm at and may just add some more ignition advance and play with VANOS on a dyno.

very nice. I like the Z4 chassis

It's underrated imo. Tons of fun and very rigid for a roadster. As rigid as a Z3 coupe, and more rigid than an E46 coupe. Mostly uses E46 parts, so it's very mod-friendly.

[pbonsalb]

350 is a great upgrade from 185, but the block is good for 500 with nothing more than a thicker HG or spacer to drop CR. It’s much more fun than 350. I would say it’s the sweet spot, the best power level. You have to deal with a lot more issues if you want 700.

[VladBelsky]

350 is a great upgrade from 185, but the block is good for 500 with nothing more than a thicker HG or spacer to drop CR. It’s much more fun than 350. I would say it’s the sweet spot, the best power level. You have to deal with a lot more issues if you want 700.

More power is usually more fun, I agree I'd like to get a limited slip differential, refresh some things, and learn how to properly handle this car at a ~400 crank hp power level first, in an autoX and track setting.

[et89]

More power is usually more fun, I agree I'd like to get a limited slip differential, refresh some things, and learn how to properly handle this car at a ~400 crank hp power level first, in an autoX and track setting.

Cool build! had some fun in a Z4 2.0i which was great, just laking power.

How about the piston rings on these M54 engines under boost?
I had a diamantschwarz 330ci coupe, great spec with a Brombeer brown interior. i loved the spec but the car was using more oil than petrol.
I traded it for my current e36.

Because of their piston ring issue I am afraid to ever touch an M54 again.
but I would like to own a Z4 3.0i coupe.

[z4JOB2004]

Great info. Currently doing the same. I have a few odds and ends to get but all major parts are in. Mine is a m54b25. Rescued from Facebook market place.