Kleemann Headers C55 Pictures
-Kleemann headers (eliminates primary cats and saves 10lbs)
-K&N air filters 33-2181 (two needed)
-Eurocharged (Toronto) tune, you can do the tune via e-mail, just need an OBDII cable that Eurocharged sells.
-Installation should take about 6-10 hours, it took us 17 hours due to seized bolts and other issues. The car is 11 years old now and is driven daily in the rust belt.
Two Mufflers (left it stock)

Resonator (left it stock)

Resonator

Secondary cats (the car has a total of 4 catalytic converters)


Stock exhaust header

Kleemann exhaust header

Stock headers (100,000 miles on them)

Stock header

Klemmann header

Klemmann header

Kleemann header

Stock headers and primary cats weight 34lbs

Kleemann headers and straight pipe weight 23.2lbs




I had the K&N air filter and the ECU tune in the car 2 weeks prior to the header install, and just those two mods made a huge difference.




I had the K&N air filter and the ECU tune in the car 2 weeks prior to the header install, and just those two mods made a huge difference.
I did the Renntech airbox + K&Ns on mine first -- no tune. On a Mustang dyno it showed about 305 HP and 316 TQ. Eventually, I got a Eurocharged tune to go a long with everything and that made the biggest difference. Unfortunately no dyno after that...
If you feel like spending more money, I would recommend the airbox!
Last edited by wawy; Jun 18, 2017 at 09:50 PM.
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The header install was a big job. One manifold nut rounded off, they had to buy a nut extractor tool and use several extensions and u-joints to get it off. Then we discovered Kleemann sent me two right-hand downpipes, so after trying to get that to work for a few hours waited until the next day when the correct one arrived. Then several hours of cutting, test fitting, grinding, cutting, etc then welding the downpipes to the stock pipes. So glad I didn't try this at home...
Dyno proven power increase ~8% across the board.
Assuming 18% DT losses that means ~380hp and 400ft-lbs peak.
Nice increase in sound.
Nitrous coming next.
Dyno vid:
Last edited by Nurburgringer; Jun 29, 2017 at 11:08 AM.
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in front of all 4 cats, and they claimed 400 hp.
So Kleemann headers without primary cats should yield more.
I only have an after-dyno, made by Kleemann in Denmark in their bench and it said 414 hp (367 orig.)
and 562 Nm (510).
After the dyno I realized that my K&N-filters were not 100% clean, maybe I could have reached
higher numbers? I will never know.
Last edited by amgen; Jun 30, 2017 at 08:37 AM.
My dyno numbers stock and then after Kleemann headers/primary cat delete and ECU tune are below.
I assumed 84% drivetrain efficiency, based on the crank HP/TQ published by Mercedes vs my car's initial, stock dyno numbers.
So the "after" power at the crank works out to ~390hp and 405ftlb (550Nm).
If I assumed 20% drivetrain losses it would be ~405hp and 425ftlb(576Nm) at the crank.
In any event the % gain wouldn't change so based on the before/after results from the same car, same dyno, testing on consecutive days with similar temps/humidity you can expect about 8% increase in power and torque throughout the rev range with headers, primary cat delete and ECU tune (primarily leans out the A/F mixture in the lower rev range).
Also a nicely angrier exhaust note under load.
Last edited by Nurburgringer; Jun 30, 2017 at 04:23 PM.


On their website they claim "up to 415 hp" (crank) with this setup.
When you say " in their bench " I assume you mean putting they put car on a dyno machine that measures wheel power, or?
As you say there are lots of variables, so the most useful information is from before and after dyno graphs with the same dyno equipment, which are overlaid to show any changes along the whole rev range not just calculated peak #s.
Last edited by Nurburgringer; Jul 2, 2017 at 08:42 AM.
Can you weld stainless steel?
Do you have a helper available?
Do you have a metal chop saw, sawsall, bench grinder&die grinder, several 1/4" u-joints and about 30" worth of extensions for getting off manifold nuts?
I can do a lot of repair work in my garage but wouldn't attempt this without saying yes to all of the above questions.
Getting a couple of the manifold nuts off is a real PITA. Aligning the existing pipes (after you cut off the primary cats) with the new Kleemann downpipes is also very fiddly, and takes muscle to move and hold the heavy 3" pipes.
The $600 I paid for installation was very fair IMO.
Instead of welding all the exhaust back together, we used a clamp to join the pipe where we cut it, this gives you a bit more flexibility down the road if you want to do any more mods or change the engine, etc. Welding is a nicer finish, but it takes a lot more time.
I'd be really curious what the dyno curve looks like with just ECU tune, since I did the tune and headers at the same time and "only" gained ~8%.
I agree with you though that the ~$1350 for Kleemann headers and installation isn't cheap, but then again neither is $800 for ECU&TCU tuning (maybe less if you catch a Eurocharged sale).
If you want cheap power go for the $430 Nitrous Express Proton Plus set-up
Even though it came that way stock, just seems wrong to have the pipes rigidly mounted, not allowing any movement with the engine.
already have speed43 airbox, k&n's and sec cat delete.
will install the headers and a eurocharged tune að soon as the shop fits me in.
Going to dyno the car after mods.*
fingers crossed it hits the numbers im hoping for.







