Bought the C55 eBay shorty headers this past July but didn't install them until now due to cooler weather in Plano. I was able to pick them up locally in Carrolton, inspect them, and negotiate a lower price, less $500 post tax. Based on the previous header post here I guess there are similar to AMS type headers. Took about4-5hrs in to install most time spent removing older headers. After install the new headers, I realized the collector was off angle and there was no way the down pipe/first cats flange was going to line up. It was off by 45*. I called up Top Speed Pro1 to verify they gave me the wrong ones and was able to exchange for the correct ones. They gave me MB#2 which fits E55 vs MB#1 for C55.

Once corrected, stock heads had one pair of thin metal gaskets per cylinder (16) so make sure those come off before installing the one piece gasket. Installation is easier due to more clearance due to less bulk of the stock manifolds.

So initial impressions: startup sounded a tiny bit more aggressive and slightly more refined. Normal driving appeared normal with no perceptible advantage or change. Going WOT on the highway appears to be most noticeable in a nice gain. Maybe ECU adapt will make it better? Doesn't appear to be a 30HP gain which my seat of the pants would detect. Maybe 10-12HP on the top end but that is just an educated guess (subjective). I already have a resonator and secondary cat delete. I measured inner diameter cylinder and collector opening and the are larger compared to stock. Measurements in pix. Just wanted to share my findings. Is it worth it????

BTW, the build quality is decent but don't have anything to compare to like the Kleeman or my SVO Mustang ceramic coated headers. Also, the pix are of the incorrect ones but the correct headers are the same EXCEPT the collector point straight down, not at 45 angle.

 

 

What you really need to open up those is a dyno tune. 10-12hp sounds about right.

If I remember correctly, a stock C55 dynos around 298whp and 301wtq? With my Kleemann and no cats or res to stock mufflers, I pulled 328whp and 372wtq on the dyno. So just guestimating you with shorties and still primary cats, 10-12hp is probably accurate, but you won't notice a major difference until you tune it!

My whp should be higher but what's hurting me now is the intake. I need to upgrade it.

 

Nice photos. Welds look good. I think the main challenge is increasing mid/high rpm hp/torque while not decreasing the low down torque and driveability which comes with it.

 

Headers alone won't really free up much flow. You need to replace the primaries with 300cell and ditch the secondaries completely.

 

I dont know how those add any horsepower, design is poor and quality is poor and all over the Chinese metal eventually cracks.

 

+1 on both. For extra $500 you could have purchased Kleemann, real 4 into 1 headers made by a well known MB vendor.

 

And use OEM gaskets, those silver ones dont last very long...

 

While I agree there are better options the design is not terrible. They were copied from the AMS style shorties and there is a before/after dyno from a forum member (SLK55) to show 7-15ft-lbs gain over the entire curve not just the top end and same with HP. Of course you will get more from mid/long tubes. The durability is hit and miss, only one way to find that out.

While the design and quality is better, I have seen the merge collector of Kleemanns... not pretty.

 

My comment was related to the "bang for the buck" factor, considering the design and the cost of installation and a possibility of a failure of a product made out of inferior materials. That said, I still wish OP good luck and give him for trying new things. Only god knows how much $$ I sent down the toilet on the way to 12.4 sec. 1/4 mile.
BTW, would my money spin clockwise or counter-clockwise in a New Zealand toilet?

 

I bought these headers in July and installed them a few weeks ago. One of the nuts that bolted to the Cats was screwed up so it didnt bolt up, only had 3 bolts secured. FINALLY got it hooked up properly today and I will tell you! You feel a huge difference in torque from these headers. The mid range powerband will make you love the car all over again. Couldn't stop flooring it tonight. Good purchase for the $

 

I am pretty sure the money goes down in the opposite direction

I know what you mean, I am trying very hard to keep my car stock.

 

I've got these on my w209 clk55. I couldn't be happier for 500$ shipped. And with my tune the car really roars. Much more mid range and top end.

 

I've also had them on for a couple months. No leaks, cracks, and the gaskets are doing just fine. I have a feeling people bash these because of the price. They are just about the same as the AMS shorties

 

I've also had them on for a couple months. No leaks, cracks, and the gaskets are doing just fine. I have a feeling people bash these because of the price. They are just about the same as the AMS shorties

 

I think they're OK for a non supercharged application but the added heat from the blower kills these over time.

 

update. still no cracks or leaks. silver gaskets are holding up aswell

 

glad to year it!

 

the headers are now off the car, they cracked at the last runner twords the collector, also the silver gaskets did indeed fail. Top Speed Pro1 did not want to do much to help me out. he wanted to weld them, they are aluminum. which you can still weld but I feel they would eventually crack again in the near future. they did provide a nice noticeable gain, a lot more top end power and with a tune they really unlock hidden power. unfortunately they do not hold up for very long. the bolt bosses on the collector snapped off aswell. too bad ams doesn't still manufacture theyre shorties. these are the same dimensions but crappy metal.

 

Told you so

 

Yeah yeah hahaha

 

Sorry to hear that. Thank you for experimenting though. I was considering having a local shop copy them since they do really top notch work. They will probably charge $2k but they give a lifetime guarantee.

Are you going to repair them, buy different ones, go back to stock?

 

For that kind of money, C32 people look into these. http://www.needswings.com/NeedsWings...nelheader.aspx
And for the 55 guys, I still stand by my previous comments regarding Kleemann.

 

I'm back to stock. But I'll be supercharged soon

 

I am in the process of getting some bolt on headers made for the C55\SLK55. The headers will bolt up to the stock down pipe so u can keep the primary cat. U should delete the secondary cats and replace the resonator with an X pipe.

Those cheap china made headers cost around a $100 if that to make. Cheap materials and cheap labor. The grade of metal is good for intercooler piping. Heat from an engine is too much and weight of the factory cat is too much. The design is poor. Very little manifold volume increase. Anybody that says they gained power from these needs to do a back to back dyno. I am would bet they only make around 10hp tops!