Hello ladies and gentlemen, pleasure to be here. I must admit that I am new to participating in a vehicle based forum so I apologize ahead of time.

Let me start by saying that I am a heavy duty diesel technician, the vast majority of my work is on Commercial Class 8 vehicles. But I assure you that am an insane gear head all the same. I have a project in mind that I would like to embark on but I have many concerns about it's actual viability and so I have come here to see about gathering knowledge. Mind you, I work for Freightliner, I AM a Daimler employee, so getting parts is not a concern of mine, but weather or not I can make the parts go together is something I'm not sure about.

I currently own a 2005 C240, Sedan, RWD, pearl white, very pretty car. I adore everything about the way this car looks, and we've already had many an adventure together. But I want more bite, and not just a little bit either. I want to build something as insane as I am.

Here's where my head's at.

Firstly, I want to Boost a C320 engine, with a factor turbo, preferably a 35mm in available, and swing it into this car, then I would like to convert it to Manual, a six speed AMG gearbox in that is doable.

Now here's where we go crazy, I would like to take the rear Differential of an SL55 and the axles and put them under this car. That is where the majority of my uncertainty comes from. There may or may not be a road trip from the Red Ball Garage to the Portofino Hotel involved in there at some point.

If anyone knows, please let me know if/how difficult to swap that rear end would be. Is such a massive conversion possibly or should I go looking into using a different differential and rear axle for such a task.

Thank you for your time.

 

Just thinking out loud - if the R230 rear differential is not a direct replacement, cutting/fabrication of the W203 rear subframe would likely be needed to mount the higher torque differential. Likely also needed would be modifications for propshaft and halfshafts. Need to figure out if there is space available for the R230 rear differential. In theory it can be imagined, but hard to say if it is doable, in practice.

 

Yeah, the more I look into it the more difficult it seems. Still, I want to put SOMETHING back there because I'm worried that a stock W203 rear end wouldn't handle the beating. Part of the reason I want a suitable AMG Manual under there is because I know it will stand up to whatever that 320, even boosted, will dish out. But I'm still trying to figure out what my options are.

 

How much power and torque do you want the engine to deliver? This will help to select the remaining drivetrain components. Space with the W203 platform is likely to be a factor. As long your horsepower goal is within range of previous M-B engines, there conceivably are options for you.

 

Now THAT is a difficult question to answer. Even two exact engines off of a matching production year react differently to Boost, and I already planed on putting better rods and mains and rings in. (One of the luxuries of this situation is that I have a fully functional car, and can take my time putting this engine together, marry it to the trans, and swing the whole thing at once) But I'd like to break 380 if I can, but logic tells me it's going to be high 300s. 350s 360s, somewhere in there. Torque will probably be a bit lower. I don't see this engine making more than 350ft-lbs with only 3.2 liters

 

Have you considered a supercharged M112 engine from the C32 AMG, it put out 354hp and 332 ft-lb. Should be a drop-in setup once you gather all of the parts.

Or the 5.4l V8 from the C55 AMG? It puts out 367PS and 376 ft-lb. Or are you married to the idea of modifying the existing engine? It seems you have options available.