[karbonphiber]

I ordered a set of Zima motorsports catless downpipes through VCM Auto Inc. and had them installed this evening.

Overall, I'm quite happy with the quality and design of the product as well as the prompt service from VCM. The welds are cleaned throughout the inside of the pipe, and are good and robust throughout, and they are significantly more lighter and less bulky than the stock units.

The design and manufacturing of the pipes made the installation relatively easy. Although I did not install them myself, the installer took about 2hours from start to finish which is not bad considering this was their first set of downpipes they had installed for an M4.

On the upper down pipe, the downstream O2 Bung had been welded 90 degrees to that of the OEM position. This made reinstalling the the sensor easier than removing it and the end connection sections were maintained round such that the stock gaskets slipped perfectly on. The only minor complaint I have about the design is that when installed, the lower downpipe fits extremely close to the subframe with just barely a few millimeters of clearance. To mitigate the potential of the downpipe hitting the subframe, I would recommend to Zima that at end where the pipe connects to the turbo should be shortened by fractions of an inch.

Other than that, the sound is noticeably deeper, and very nice and loud when opening up the throttle. The crackles and pops are more pronounced as well as the spooling sound of the turbos.

What I was really impressed with was how much more pull I was getting with them installed. These are going to get me into some serious trouble!

On to some pics: