This was an experiment… Six speed from a 2014 Ssangyong Actyon. I diD mY oWn rEsEaRcH as best as I could, and was reasonably confident that the Mercedes-Ssangyong connection was sufficient that it would work. But it doesn’t.
Two main problems:
the bell housing bolt pattern is different. The only bolts that line up are the starter motor. the flywheel has a different offset (front to back). The Ssangyong flywheel is too flat and touches the block before it meets the crank.
Bugger! At least it was cheap.
Next idea was to make an adapter plate to suit a BMW gearbox. The core flute is *proof of concept to make a template* - there needs to be a steel or aluminium made as a template before I commit to the real thing.
Had a bit of a panic that the MB flywheel doesn’t fit inside the BMW bellhousing…
…but then realised that the correct flywheel will sit within the block/adaptor plate, and doesn’t need to sit inside the bellhousing at all.
I have convinced myself that it will work. Now to buy some 8 or 10mm aluminium.
Still don’t know what I will do about a manual flywheel. There’s a single mass conversion available, which is probably the right way to go.
Also need to wait until I go back to work to machine up a spigot piece to centre the input shaft on the crank.
So, I pulled the manual box and shifter out of the W202 C180. Bit of a question about what 202 parts will fit into the 201, so this was another gamble.
The shifter is going to work, but the shifter surround will need to be modified. The smart solution is to fit a W201 shifter boot, but I will look at making a new surround to take the W202 boot (because tight arse).
Onto the Suzuki GSXR1000 throttle bodies. These came off the Camira motor, so had already been spaced out to 93mm port spacing - but I need 97mm.
It’s an easy job to fit longer spacers and extend the linkage arms but the multi-piece fuel rail is more difficult. I have ordered some 16mm long spacers but wanted to see if the Camira-length fuel rails would work with the Mercedes spacing, so I bodged in some washers.
…and it is going to work. The Suzuki GSXR1300 injectors fit into the 1000 rail/throttle bodies and are about large enough for the power I want, but there’s no shortage of upgrades available if they aren’t.
Toyota COP coils left over from the old NA MX5 look like they will be an easy conversion. My main indecision here is whether to use the factory plug cover to hold them down, or ditch the cover and make a bracket that uses the cover’s mounting points.
Last way to melt my brain was to look at the diffs.
The ‘dark black’ diff on the left is BMW E21. Middle diff is the small case Mercedes diff from the C180 with the ultra-rare 3.9 ratio (this is the shortest MB car ratio that exists). Last diff is the medium 3.07 diff from the C220.
The BMW diff looks like being a relatively easy conversion (ha!) and has the advantage that I can fit 4.45:1 gears from an automatic E36. This will work nicely with the MB overdrive gearbox.
Alternatively, the 3.9 Merc diff will work well with the 1:1 too gear BMW box…
The big diff is useless for a four cylinder rally car, so will only be used in a roadie.
There is some chance of a Ssangyong Stavic diff being useful. They are even larger than the C220 diff, and are available in a wide range of ratios (from 3.07 to 4.89:1). The trouble is working out what ratios Australian Stavics came with, and then finding one at a realistic price.
Right now, I am thinking the BMW diff and MB gearbox is the easiest tolerable solution, but the BMW box’s much better ratios are definitely appealing.
Eh, I will work it out at some stage.
