Kevwood

Well, it seems like I’m a noob again because I haven’t been around for so long! As I’m sure everyone here knows, the Middle East has been ‘interesting’ the past few months and it’s made working here pretty challenging. I thought that traveling all week every week was enough of a challenge but I was sorely mistaken, anyways, things are settling down now and I am starting to have a little free time again so I need to get caught up.

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

mikata

Glad to see you're back Nice numbers!

dynomite05

Glad to see you back, KeV! Those are some good numbers, specially when the tune ties everything together. What ultimately matters is how happy you are. You owe us a vid and sound clip when you get a chance. Happy to see that all is well and lOoking forward to the rest of your mods.

elijah

Great info & Welcome back.

Where do you guys find E55k airboxes? Ive been checking ebay for a few weeks but nothing. Is there a source out there that sells them?

dynomite05

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.

Kevwood

Hey Wes. Yes, I was very pleased with the end result and as I have said for a long time now, a custom tune is the only way to go if you have anything outside a 'stock' car. The difference is really noticable from the mid range on, the bottom end is pretty crazy now too, the traction control kicks in almost immediately on less than half pedal. Something I should make very clear mention of is that the throttle position relation (pedal depression vs. TB opening %) was NOT adjusted on this tune as most tunes do to give the car a stronger kick/sensation off the line when not at WOT - this was a pure A/F & timing tune done under my supervision. We did it proper and did it right - a task when it's 106*F and humid out!

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.

Clkboi

Kev welcome back man glad to hear everything is ok.

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.

2MCHCAR

I bought mine on the forums as well. BTW, I'm going to sell my old E55K airbox (and a bunch of other parts) as soon as I can find where I put it (Kleemann Supercharger Kit came with it's own airbox).

Welcome back Kev!!!
We were getting worried about you, glad everything is okay and your build is progressing nicely.
Can't wait to see the pics!

M-bENZ

I cant believe the AMS headers only give you 2 hp ? and we have to pay a thousand for that ? seems like what you really gained here is the 2nd cat deleted and the magnaflow muffler and welcome back Kev

Richie999

I am a newb on the MBZ scene, with several years in the Mustang scene.

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????

ahmadk

good to see you back Kev ... nice numbers

Newjd2

Great inspirations for 500's...great job Kev and welcome back of course...



Angelo

elijah

PM me when you are ready to get rid of it, I am def interested!!

buffyclk500

what was your tq

Kevwood

Thanks for all your comments guys, I've been fine, just very busy trying to work and travel around all the issues over here the past few months. Still though, I love it. Now, after last nights announcement things could again really change... Time will tell.

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.

Kevwood

Hey Andy. Yes, the headers on my car averaged (all mods got 3 dyno runs) 2hp. To be completely fair to AMS here this could have been due to clogged secondary cats because the numbers jumped dramatically after the stock exhaust system was completely replaced (with the exception of the OEM primary cats and downpipes) but that is a little unlikely. I remember reading a review on the AMS headers installed on a SLK55 AMG and the gains were (IIRC) 6 or 8hp. We have to remember here that these are more 'tubular exhaust manifolds' than an actuall 'traditional' header that has a collector and in cases of well designed systems, equal length runs.

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.

Kevwood

The operator of the dyno/tuner said that he uses the above mentioned corrective values for MB's with 5 and 7 speed tans. He's done lot's and lot's of them and said that when using those values the bhp shown on the dyno matches the spec hp very closely. This of course is not to say that it is the same on other dynos but it certainly appears to be the case on his.

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.

dr_npz

Those numbers are huuuge Kev ! Glad to see you back here on the forums.

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.

dynomite05

kostas86

Welcome back and nice numbers!

M-bENZ

I think imma pass on the headers for now and since my exhaust is done i only need to get my ECU tune...we'll see what kind of number it will put out with the C55 AMG airbox

Kevwood

Here is the link to my exhaust thread if anyone is interested in a review of the AMS headers;

https://mbworld.org/forums/clk-class...ew-thread.html

BHeart

What would be interesting (even though I would never request it), is if Kev could have re dyno'd after getting the exhaust upgraded (2nd cat delete, and magnaflow mufflers) with the stock headers. That way if the the figures went down by the same 2hp that they changed to when he first installed them then you would have definitive evidence that the impact of the AMS headers were minimal (from a hp standpoint).

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

Kevwood

I agree and that would have been done but the big problem was the AMS manifolds were not the correct ones for my car so the downpipes had to be modified, there for there was no chance of doing a simple manifold swap to get another dyno run test. I detailed it in my AMS thread;

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.

M-bENZ

I wonder if there is a longtube headers for our cars but then not sure what to do with the primary cats...headache ?