31 January 2026:
Have to back date this one a little, as pictures were taken, and work began, but this thread was not updated. Acquired a set of W205 C63S seats for the project. Unfortunately, there are two major problems with them. One is that the controls for the seats are on the door panels, and the second is that the computer for the seats is more than a little difficult to integrate into the W209 electronics this car will be running on. The easiest solution would be to use the seat controllers from a W164 ML63 that was parted out several months ago. This would allow for most of the movements of the seats, along with seat mounted controls. The physical mounting of the switches will need the side panels to be cut out of the W205 seats, but that has been done before on the M113K Crossfire, and it can be done again, here.


W205 Seat Controller

This is what the seat controller looks like. The one for the W164 is similar, but an older generation that will play with the W209 electronics of the car a lot better. It would have been possible to translate the protocols, and allow the W205 seat controller to work, but then this would have a domino effect, requiring switches in the doors, which would require cutting up the door panels, mounting them, then trying to make W205 door controllers work, which also would not play well with the rest of the car. Skip all that, and do this:

W205 Seat Controller removed and wires traced out

After removing the W205 Seat Controller, the wires for each motor or other function, such as heating, ventilation, airbags, Airscarf and power lumbar control were all identified. Then the W164 controller was added into the seat. This was tested, but have not finished up making it nice and neat, so there will be an update to this step, soon.

 

Very interesting. Now I'm glad that I have a base model! LOL

 

14 February 2026:
Progress on this project has been slow, due to work and life commitments, but looking forward to stepping up the pace in the coming weeks and months. The seats ought to be finished up in the next day or so. In the meantime, work resumed on engine, including mounting the exhaust manifolds that were made by @NeedsWings . Rob did a fantastic job on these, but the arrival of suitable hardware took a lot longer than expected. I did not want to use regular OEM hardware on these, as experience has shown that with manifolds like these, it will back out. I wanted to use Stage8 Locking Fasteners, which much luck has been had in the past. There was a problem, of course. Mercedes in their infinite wisdom did not use a typical size or thread bolt for the exhaust manifolds on the M156. The M112/113 uses M6. Very typical size. Other engines use M8. Veery typical size. The M156? Some engineer thought M7 - a completely oddball size - ought to be used. Does Stage8 offer M7? No. Does anyone? No. Off to China we go!

Nice, gold anodized titanium bolts
After waiting for about 6 weeks, a set of 20 M7x25 titanium bolts arrived. Using Stage8's service, these were shipped to them to be modified to allow their locking system to work on it. This turned out to be very pricey, but not having the headaches of this in the future makes it worth it.

Close up of the locking fasteners
These work by slipping the teardrop shaped aluminum locking tab over the head, and then adding the locking E-clip in place to hold them. Now if the bolt tries to work itself out, it can only go so far before the locking tab will hit the manifold, stopping it from going any further. This will keep the fasteners tight, and keep the exhaust manifold gaskets from leaking. If you have ever had a car with a set of headers, then you know what blown manifold gaskets sound like. This will help with that problem tremendously.

Here's some pics of the manifolds in place:





Continued in next post:

 

14 February 2026 (continued):
Next, the motor mount plates were added. These need to be powder coated, but a test fit of the engine will be made, first, just in case they need to be modified before the final go on this:





One last touch for today was to add SAI block off plates. There is not one for the M156 available, but fortunately M113 style plates can be easily modified and used:

The small aluminum plate from Benzformance blocks the SAI ports, as they will not be used in this application

That's all for now. More to come soon.

 

To be fair, no Crossfire came with seat controllers. This is all part of modifying the Crossfire into a more modern take on the whole concept.