W204+M156

So why does the M156 (6.3 V8) engine produce 451 hp in the C63 and not 518 hp like the SL63? In theory it is the same engine in both. I understand they want the people paying $140k to feel they are getting more than the people paying $60k. No question there. I am curious exactly what was done to “de-tune” the engine for the C class. From what I can tell there is a standard intake for all the 63’s. I have read that the exhaust pipes are 2.5 inches on the C63 instead of 2.75 inches like on the upper models, so that’s one factor. But is that it? Then what about the CLK63, that has 475 hp? And the E63 with 507 hp? The way the engine is able to change performance levels depending on the different markets with a range of more than 10%, tells me something else is going on behind the scenes. Does anyone know if the timing is different between the 63’s? MHP? How about other tricks that were used to change the horsepower on the C63? I don’t care about what could have been done, I am only interested in what was actually done in this case. (please no blind speculation)

On a side note, having the same engine as the more potent cars is the ultimate excuse to tune the ECU of the C63 in my opinion. I know the engine can do better; no doubt the components can handle it. I paid for the engine and I want its full potential!

Merc63

This is why the tuning guys are able to get 510ish HP from these engines with just an ECU flash. I would think the timing is kicked some to reduce HP.

FFemt5287

Might it be traction control and drivability issues? To my understanding, its the same transmission, so I'm ruling that out for myself.

451/443=EW

Its a 6.2L V8

bigbodybeeenz

The difference is software and exhaust

BerBer63

I thought it was 6208CC V8

MHP

MB doesn't want the pony out running any of the horses, hence the detuning and more restrictive exhaust. Ironically by far the worst air inlet tubes are on the CLK 63 BS, convoluted doesn't even do them justice.

yooker

I got a question about this and similar engines. Do you know what is the significance of a verticle air intake duct to the cylinder? I've been browsing the internet and noticed most of the V8's have a verticle intake duct, RS4, E9X M3, 63s, LSx engines.

Thanks!

MHP

I'm not really sure what you're asking...Are you talking about port angles?

yooker

Thats what I meant, port angles. Sorry for my incoherent paragraph, I am not very good at getting my point across.

MHP

NP. The port angles on 6.2 heads are very racy for production heads. I'd put them in the same class as the E9X M3 and E6X M5/M6 heads, wicked out of the box, though the extra displacement of the 6.2 will allow for larger gains than the other engines with porting/cams.
The more vertical the port angle the less acute the short turn radius in the cylinder head needs to be, meaning the incoming A/F charge has a straighter shot into the chamber which is always a good thing.

yooker

Thanks very much

W204+M156

That is interesting, and that makes 500+ hp.

yooker

So the M156 engine has 2 throttles inside the intake manifold. While the E6X M5/6 and E9X M3's have an individual throttle for each cylinder. Besides better throttle response, is there an advantage to their design?

Eurosport

why do people not do a search before they actually start a thread?
oh wait it's c63 forum doh

MHP

It's in the tune.

MHP

Correct, the 6.2s have twin 74mm TBs in the manifold. The E60/90 Ms have an individual TB per cylinder (ala Kinsler intake). Given the choice, sure, I'd love to see an individual TB setup on the 6.2. It's a far more complex system but it definitely works--especially at higher rpm.

W204+M156

I found this in another thread, very helpful.

paulGT3

Then there would never be any forums and everybody would be afraid to ask a ?
Plus the searches are a joke. You cant put two words together and get a coherent answer.