Part 2: Bodywork
I won't list all the part numbers here since they are all covered in Marco Svizzero's original post.
Since the original intent for this car was to be a trackday car that wasn't too unfriendly on the road I had more modest plans for the body than some of the other 1M conversions I'd seen. This was mainly the choice of Prior Design fiberglass rear guard extensions rather than OEM repair panels and a plan to keep the 135i battery tray & mufflers.
The Prior Design 'rear widenings' make the rear guards mod a lot simpler and save a fair amount of money. I also liked the idea of avoiding a potential rust issue with cut and welded panels when the backside of the panel usually isn't painted in the other method.
The main downsides were:
-I had to organise shipping from Germany which was a total PITA
-The length of the guard opening is off by about 5mm so it creates a slight mismatch with the side skirt (I plan to have this fixed at a later stage).
They blended in well and look OEM after paint.
The rest of the panels were OEM BMW which were actually quite reasonably priced to buy locally- about $3800.
At this stage there are a few decisions to be made and this is where my OCD started diverting the project away from track rat to a more complete conversion.
The 1M headlight washers are different so the options are:
-Cut the bumper cover to fit 135i washers (the mounts are still on the 1M headlight brackets)
-Delete the washers (technically a defect)
-Use 1M washers.
I swapped to 1M washers
The 1M doesn't have front parking sensors so the options are:
-Code them out of the 135i
-Drill holes in the bumper, buy mounts and use the 135i PDC sensors.
I elected to fit them.
The engine bay undertray and inner guard liners are all different. The front guard liners definitely need to be swapped out, the rears are probably better trimmed (I went this way since my Prior guards probably won't perfectly match OEM liners) and the undertray is optional but would leave some gaps if not changed.
Side indicators were black painted & tinted units from IND
Despite the original plan to keep the OEM 135i battery tray it started looking like a bigger hassle to mod the exhaust than to just swap everything to 1M and use an off the shelf 1M exhaust.
If you follow the US conversions they go to great lengths changing the evap canister and lines. This isn't necessary on Australian cars. The layout and position of the canister here means it can be moved just with some trimming and bending of the stock lines. All that is required here is the battery tray, heat shield and battery hold down. The battery leads can be extended or replaced (they are quite costly so I extended them with high quality cable splices).
The exhaust is a Megan Racing 1M system which I wouldn't recommend for N54/N55 as it is very quiet. It should be about right for the S65 though.
The next important detail was suspension and wheels.
After having KW and Ohlins on a couple of previous cars there was no doubt what would be going into the '1M'. Ohlins Road & Track with Swift springs and Vorshlag Camber plates. Camber and toe arms have all been swapped to Rogue Engineering adjustable.
As noted in other threads the 135i uses wider rear hubs than other models including the 1M. To use aggressive 1M wheel fitments needs either swapping out these hubs or using higher offset wheels. This is another area I wouldn't have swapped if I knew I was going to the M3 rear end but seemed reasonable at the time...
The rear hub mod uses some specific 130i parts to match the 1M hub position but allow use of the 135i rear brakes.
Brake discs:
34216795755 slotted
34216787931 plain
Both are expensive and take a while to get so I used some aftermarket ones from Germany.
Hubs:
33-41-6-760-058-M36
Wheel bearings need to be replaced as part of the swap 33-41-6-775-842-M842
It's a bastard of a job or up to $1k labour so only really worth it if you want full compatibility with 1m / M3 wheels.
The current wheel/tyre setup is VMR V710 in 19x9.5 with 265/35 front and 19x11 rear with 295/30.
That brings us to the sort of finished product of this phase:
