I recently bought a 2006 SLK55 AMG and searched everywhere for an affordable set of short (drop in) headers. The only ones that fit the bill were the Topspeed Pro-1 ones on Ebay. They look exactly like the old AMS shorty headers.
Given the price ($475 shipped), I figured that there may be fitment/quality issues, but I also figured it wasn't a huge risk either, so I went for it.
Also, I used this very helpful DIY thread: https://www.slkworld.com/slk-r171-cla...placement.html
Since I couldn't find any info on SLK owners trying these out, I thought I'd post my impressions....
First off, the customer service at this place it top notch. I had two returns, and both were handled professionally and quickly. Every time I called, someone answered, and all my emails were returned quickly.
1) Fitment: Fitment was spot on, zero issues with fitment. Once installed there were no leaks, nothing was forced, etc. This was my biggest concern when I purchased these, but it was not an issue at all.
2) Quality: Average overall. The main thing is that there is a lot of over-weld inside the header. It was no big deal since I have an air rotary tool and carbide grinding bits, but it you don't have the tools, I'd think that you'd want to get them cleaned up. Other than that, the welds are solid and all the way through, and the flange is clean and 1cm thick. The flanges were slightly
warped, but it was very minor and flattened out once bolted down. I've modified cars for the past 15 years (3rd gen RX7s), and these certainly do not have the nicest build quality, but they look like they will work as advertised.
3) Extras: They came with a single compression gasket for each side. I prefer the metal stock gaskets, so I picked up a set for an additional $30 on Ebay. They also came with 4 extra studs to attach to the downpipe, but I used the stock torx bolts.
4) Performance gains: I don't know if their claims are accurate or not, but their inner diameter is a 1/4" thicker than stock (inlets are 1 5/8" vs 1 3/8" and outlet pipe is 1 3/4" vs 1 5/8"). They also look to flow better.
5) Driving impressions: The sound is slightly more throaty than stock and is noticeable at the mufflers. Sounds great overall. There was a clear performance gain, but it's hard to tell how much. The car certainly felt crisper and more responsive. I would guess around 15 whp or so.
Overall, I'd recommend these to anyone who is considering short headers. They are probable going to give you 5-10 less whp than Renntech headers, but they are $3k cheaper
Pics (note that in some of these pics, the passenger side header was for another MB. I exchanged it with zero issues):
Stock Inlet Ports vs. TS:
Compared to Stock (passenger side is incorrect in this pic):
Ports after over-weld was cleaned up:
Installed (hard to get good pics, but fitment was perfect):