I've read there's a difference in horsepower of 16 -18 between the SRT-6 and it's Mercedes counterpart. Does anyone know the direct cause? If so, wouldn't that be the easiest way to gain extra horsepower? It's the same engine after all...

 

I believe the intercooler has a larger heat exchanger, thus keeping the air cooler and likely making more power.

Otherwise, as far as I know, the only thing that may be different is the ECU - I believe the actually mechanical parts are identical.

SQ

 

Renntech started a rumor that the camshafts are different, but I would not take their word for it... The exhaust set up is different, but the srt is not proven to be more restrictive if anything it has proven otherwise... The ecu may POSSIBLY be differently programmed...

I do not think so... I have yet to be proven there is a loss in horsepower in the crossfire...

 

So do you think the actual horsepower is the same? Making the rated horsepower difference just a marketing ploy?

 

The SLK32 and SRT-6 share the same heat exchanger. The C32 sedan has the larger one.

 

Yes underrating horsepower is legal, unlike overrating it... rx-8 comes to mind...

 

So what is the actual RWHP on the SRT.

 

I know there rated 330 at the flywheel but to the tire most cars lose between 50 to 100 hp.

 

Depends what dyno is used and conditions... 280-300 sounds about right... though.

 

That marketing myth has pretty much been de-bunked. It would seem that Chrysler under rated the SRT-6. Not unusual for them. They did the same thing with the SRT-4, Cummins 5.9 TD, SRT-8 etc. I have done the math of plugging in 1/4 mile times, trap speeds, car weight, drag coefficient, head wind, humidity etc. These calculations gave me a Rear Wheel Horsepower figure of 285-295. Now figure a 20% drivetrain loss and the flywheel HP number is actually closer to 355-360 HP. The Crossfire actually usually runs BETTER than its MB counterparts in 0-60 and 1/4 times. I attribute that to it being a little lighter and more aerodynamic.

I seriously don't think that MB would have taken the time to re-engineer and test another set of cams for such a short production run. It would have cost too much money, and why mess with something that is already perfected and proven. Just doesn't make sense. RennTech is the basis of this "story" and I think they were just trying to sound smart by coming up with a speculative mechanical reason for the stated HP difference. I've heard that someone actually pulled the cams from both cars and there was no difference at all. I also don't think the ECU is all that different either. If it was that much difference I don't think the many MB tuner programs out there would transfer over the Crossfire as transparently as they do.

 

I think all the difference in HP is in the AMG badge. I ordered one and instantly dropped a few tenths in the 1/4...

 

I doubt there is any difference between the motors in the SRT6/SLK 32.
I believe over on srtforums, a SRT tech said there is no difference.
The exhaust are different, but Sidez is right, ours is no more restrictive.

Feel free to take each motor apart and let us know for sure though - .

 

It's so easy to gain/lose HP with a little tweak of the ECU. I wouldn't be one little bit surprised if MB decided that the "Chrysler variant" of their SLK simply would not be allowed to make more HP so they detuned it ever so slightly.

In 2004 Chrysler introduced a lower HP version of the PT Cruiser Turbo. There is no difference whatsoever between the HO GT engine and the Turbo "Lite" of the Limited Edition cars. Same internals, same intercooler, same turbo, same fuel injectors, same intake, same everything. The ECU programming in the GT gives more boost and different timing, is tuned to run on premium fuel and allows 220 HP out of the engine. The ECU in the "Lite" drops max boost, retards timing, is tuned to run on regular and makes but 180 HP. With either engine the Stage 1 upgrade is simply an ECU swap and it takes both versions up to 240 HP. I don't see why DCX wouldn't have simply done the same sort of thing with the SRT6.

 

They would not of done this simply because it is to much to do... it is much easier to just state the number is lower...

But if anything this theory is the only one that might actually be true...

 

The real question would be what are the stock slk32 amg's running in the 1/4 at the same tracks on the same days. There are plenty of 12.7-12.9 stock srt/6's it would seem and that would confirm to me that it is the same car basically.