Mods vs dyno gains
Right from the beginning of my build project I said that I would be dyno’ing the car between mods to present actual gains – I have in fact followed through with that and present the results so far;
Car in complete stock form: 221
AMS headers with stock exhaust: 223
AMS headers with full new exhaust, 2nd cat delete and Magnaflow: 239
AMS headers, full exhaust, AMS pulley and E55K airbox/BMC filters: 246
As you can see, the results of the bolt on mods are not too bad at all considering that the car was running a complete stock ECU tune. You can read into the numbers in a number of different ways, aka, headers aren’t much of a gain OR the headers work great with a free flowing exhaust… Obviously deleting the 2nd cats and the chambered muffler allows the car to breath considerably better, add into the equation the headers pulley and airbox, I ended up with a number that was a higher than I expected.
Now, as everyone here knows I plan on adding a Kleemann supercharger when/if I can get RTA approval (or find a way around it) so I was not going to spend $1,000USD on a custom dyno tune that would just need to be re-flashed anyways but…
Curiosity got the best of me

AMS headers, full exhaust, pulley, airbox/filters and custom dyno tune: 277
The car spent about 3 hours on the dyno and the en results (in my opinion) are fantastic! The German tuner has asked me to come back in a week after the adaptives have settled and he wants to finish up the top end that he said is still begging to be cleaned up with a leaner mixture and maybe another dot of timing. The car was seriously heat soaked and the climate controlled dyno room was getting really hot so he felt he had done enough for one day. He is quite positive that the settled number will be 280 and that he can drop another 5 or so hp in there. We will see. For now the car idles as smooth as glass (had a slight surge and lump before) and is an absolute blast to drive.
For those who are wondering what the crank numbers would be, the tuner told me that on his dyno they use a corrective value of .75 for a MB 5 speed and .73 for those with a 7 speed. Using his numbers, the stock number is incredibly accurate;
302 * .73 = 220.46 The car originally dyno’d at 221. So, using that formula 277 would be about 379.
At the end of the day, the number doesn’t really mean much to me nor does the quarter-mile time because the car isn’t being built for that, it’s built for road-course racing where mid-range and top-end power are essential. It is however very interesting to see the gains each step of the way.
So, that’s it for NA numbers (I’ll update this thread after I go back for the ‘top up’ tune), hopefully the SC numbers won’t be too far away
If found mine used on the classifieds in this forum. You could always buy it new from parts.com. I can't recall the price, but if you search on the C32/55 section for SL55 airbox you should find the part numbers.
I'll be more than happy to post up some vid's and sound clips but it'll have to wait until the weekend, I'm off to Kuwait at 5am tomorrow so for now I'll just get some updated pics and spec up.
Talking about airboxes i was going to make a thread about it.
Anyone can tell me if i can get a better airbox for the 350 Engine?
My ECU is on top of the engine and not on the side like some of you guys here.
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I'll be more than happy to post up some vid's and sound clips but it'll have to wait until the weekend, I'm off to Kuwait at 5am tomorrow so for now I'll just get some updated pics and spec up.


We were getting worried about you, glad everything is okay and your build is progressing nicely.

Can't wait to see the pics!
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Right from the beginning of my build project I said that I would be dyno’ing the car between mods to present actual gains – I have in fact followed through with that and present the results so far;
Car in complete stock form: 221
AMS headers with stock exhaust: 223
AMS headers with full new exhaust, 2nd cat delete and Magnaflow: 239
AMS headers, full exhaust, AMS pulley and E55K airbox/BMC filters: 246
Is the OP really suggesting that he loses 100 HP from the crank to the rear wheels? What am I missing? MBZ has a 100 HP parasitic drag loss????
As for the numbers, yes, they are pretty darn good and came as a surprise especially after the very low initial number. But then again, the time around the track is all that really matters to me, this post was just to follow through on my promise to post gains per mods - I hope it proves helpful to the members here that are considering options.
Physically looking at the exhaust system, the cats and the chambered muffler are the two primary restrictions. Although the AMS headers are designed and built well, they are replacing a manifold that itself is similar and obviously creates very low flow restrictions.
In the end, the headers seem to work very well as a system with the new exhaust and offer an dramatically different sound note. When I get back to Dubai I will finish my AMS/exhaust review thread (with pics and a sound clip), it will be far more helpful than this brief writeup.
If time permits I'd like to run the car on another shop's dyno to see the difference but dyno time here is brutally expensive and as mentioned a few times before, the final dyno number really means nothing in the end, I was just doing this to post mod gains.
Back in Canada my Chevy with a 4sp auto trans presented a loss of almost 30%, the same car after a 5sp swap showed 22% (calculated by gains shown).
I think it was 314ft/lbs, I'll check for you when I get back to Dubai.
However, i am really disappointed with the AMS headers. I was always thinking that gains cannot be big, but 3hp. That conclusion makes me consider kleeman headers.
Physically looking at the exhaust system, the cats and the chambered muffler are the two primary restrictions. Although the AMS headers are designed and built well, they are replacing a manifold that itself is similar and obviously creates very low flow restrictions.
In the end, the headers seem to work very well as a system with the new exhaust and offer an dramatically different sound note. When I get back to Dubai I will finish my AMS/exhaust review thread (with pics and a sound clip), it will be far more helpful than this brief writeup.
Physically looking at the exhaust system, the cats and the chambered muffler are the two primary restrictions. Although the AMS headers are designed and built well, they are replacing a manifold that itself is similar and obviously creates very low flow restrictions.
In the end, the headers seem to work very well as a system with the new exhaust and offer an dramatically different sound note. When I get back to Dubai I will finish my AMS/exhaust review thread (with pics and a sound clip), it will be far more helpful than this brief writeup.
https://mbworld.org/forums/clk-class...ew-thread.html
At this point, its hard to tell if they are acting (in military speak) as a "force multipler" when added with the proper exhaust, or if they only provide 2hp benefit regardless of the exhaust.
Just a thought
Last edited by BHeart; May 12, 2011 at 11:58 AM.
At this point, its hard to tell if they are acting (in military speak) as a "force multipler" when added with the proper exhaust, or if they only provide 2hp benefit regardless of the exhaust.
Just a thought
https://mbworld.org/forums/clk-class...ew-thread.html
I agree that they work well on a complete free-flowing system but on a factory system with a chambered muffler, there just wasn't much there.


