First some background, I bought me a nice Valencia Orange 6MT 228i slicktop back in the fall of 2022 as a sedate daily. Car was mostly stock save for a catless DP, Active Autowerks dual-exit axleback, and 17x9 ET30 Apex ARC8s. But the modding bug soon bit, so I started throwing parts at it left, right, & center. Highlights include the following:
complete M rear subframe with custom 188mm 3.91 Torsen LSD rear diff, with custom axles
M235iR front subframe with M aluminum undertray/bellypan & M235iR-specific front/side panels
M235i "2VL/Sport" steering rack
4x M front arms
28mm adjustable front sway bar (since an M bar wouldn't fit the non-M subframe)
M front knuckles/spindles with my custom 350mm brake setup (exact same setup I run on my 1er)
M2 Competition shocks with H&R Sport lowering springs
M2C front brace (with M shock mounts)
Custom Carbonfiber driveshaft
M engine mounts & transmission mounts
Recaro Pole Positions with custom 1pc mounts
17x8.5 +40F & 17x9 +52R Apex ARC8s, because the M rear subframe is +18.5mm wider per side, it was very difficult to find a wheel that would fit a narrowbody
Drivetrain was kept stock, save for a custom MHD tune which got it up to ~295-300 bhp & 420-430Nm of torque. 100-200 went from 17.7 pre-tune to 13.8 post-tune, so it was now *almost* as quick as a stock M235i, and slightly faster than a stock E46 M3. No intake no charge-pipe no FMIC, just DP & tune. I briefly tried running a LWFW (SPEC aluminum 6-bolt N54 that was on my 1er) but NVH was completely unacceptable so that came back off after a week.
Car eventually morphed into a pretty competent overall package, a 1400kg 4cyl M2C facsimile if you will. Tried my hand at a few race events, and won my class in the first (and so far only) event I did with fresh semi-slicks . Was the 2nd fastest 2WD street car overall that day, just behind that pesky 991.2 GT3 again.
So now the car got to the point where it was over-chassis'd & underpowered, so when I was at my friend's shop one day, and I happened to stumble upon a 2020 AMG A45S M139 turbocharger, I immediately knew what must be done. This thing has B58-sized wheels, but with ball-bearing construction, and a compressor wheel designed for higher PR operation shown to be good for >500whp. So I got to work adapting it to fit a dummy N20 block I had laying around , and several iterations later this is what I came up with.
Was close to finalizing everything, even fabbed new oil/water lines for it and started work on the EWG adapter, and just before everything was ready to finally bolt-on, I pay the same buddy another visit and see a shiny Gen1.5 2019 M240i BMW AG Test motor, used to calibrate NAVI software with just 39,276km, in a metal crate, silently urging me to take it home ...
So there I had it, the opportunity to get myself into B58 ownership for relatively little financial outlay, on an already highly-developed car, in a rare/unique color, and most importantly NO SUNROOF, since I refuse to own anything with a sunroof. Plus I already had a G8x S58 6MT transmission + flywheel & clutch lying around the shop, so it took me all of about 3 seconds of deliberation before telling my buddy to load it up & #sendit! Any of you fellas out there want the absolute BEST N20 turbo kit on the market? @WhyAnN20
To be continued...
complete M rear subframe with custom 188mm 3.91 Torsen LSD rear diff, with custom axles
M235iR front subframe with M aluminum undertray/bellypan & M235iR-specific front/side panels
M235i "2VL/Sport" steering rack
4x M front arms
28mm adjustable front sway bar (since an M bar wouldn't fit the non-M subframe)
M front knuckles/spindles with my custom 350mm brake setup (exact same setup I run on my 1er)
M2 Competition shocks with H&R Sport lowering springs
M2C front brace (with M shock mounts)
Custom Carbonfiber driveshaft
M engine mounts & transmission mounts
Recaro Pole Positions with custom 1pc mounts
17x8.5 +40F & 17x9 +52R Apex ARC8s, because the M rear subframe is +18.5mm wider per side, it was very difficult to find a wheel that would fit a narrowbody
Drivetrain was kept stock, save for a custom MHD tune which got it up to ~295-300 bhp & 420-430Nm of torque. 100-200 went from 17.7 pre-tune to 13.8 post-tune, so it was now *almost* as quick as a stock M235i, and slightly faster than a stock E46 M3. No intake no charge-pipe no FMIC, just DP & tune. I briefly tried running a LWFW (SPEC aluminum 6-bolt N54 that was on my 1er) but NVH was completely unacceptable so that came back off after a week.
Car eventually morphed into a pretty competent overall package, a 1400kg 4cyl M2C facsimile if you will. Tried my hand at a few race events, and won my class in the first (and so far only) event I did with fresh semi-slicks . Was the 2nd fastest 2WD street car overall that day, just behind that pesky 991.2 GT3 again.
So now the car got to the point where it was over-chassis'd & underpowered, so when I was at my friend's shop one day, and I happened to stumble upon a 2020 AMG A45S M139 turbocharger, I immediately knew what must be done. This thing has B58-sized wheels, but with ball-bearing construction, and a compressor wheel designed for higher PR operation shown to be good for >500whp. So I got to work adapting it to fit a dummy N20 block I had laying around , and several iterations later this is what I came up with.
Was close to finalizing everything, even fabbed new oil/water lines for it and started work on the EWG adapter, and just before everything was ready to finally bolt-on, I pay the same buddy another visit and see a shiny Gen1.5 2019 M240i BMW AG Test motor, used to calibrate NAVI software with just 39,276km, in a metal crate, silently urging me to take it home ...
So there I had it, the opportunity to get myself into B58 ownership for relatively little financial outlay, on an already highly-developed car, in a rare/unique color, and most importantly NO SUNROOF, since I refuse to own anything with a sunroof. Plus I already had a G8x S58 6MT transmission + flywheel & clutch lying around the shop, so it took me all of about 3 seconds of deliberation before telling my buddy to load it up & #sendit! Any of you fellas out there want the absolute BEST N20 turbo kit on the market? @WhyAnN20
To be continued...
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