Dang!! If I didn't have to spend the $4,700 I have on my trailer.....I know where it would be going.

 

I've found them for $3,700. AK - didn't you have to do some grinding on your pipes? I wonder if they have stepped up the finish quality?

 

$3,700 is not a bad price at all when you think about it. No where else can you get a set of twins using two custom S300 turbos (same platform as the B1s) for $3,700, complete with ATS manifold and intake system (not just an AFE stuck on the end of the pipe). It really is a good value set of twins for everything you get. I just wish BD had spent the time and money to put an external wastegate on this set. There is obviously plenty of profit left in them at their current price given the deals some vendors are able to sell them at. Boost would be much easier to adjust and they would run much more efficiently at higher boost levels….but hey, who needs more than 60lbs anyway, right?

Yeah, lots of grinding. It is obvious they spent a lot of time on fit (everything went together extremely well) and the finished appearance of the outside of the system. They look really good under the hood. However, the flanges that they welded onto each end of the hot pipe were pretty ruff on the inside. They didn’t ensure the inside flanges were the same diameter of the pipe (they didn't take enough metal off) and they stuck out into the exhaust flow a good 1/4" all the way around. Welds that came through the joints were not cleaned up at all. The exhaust gas energy coming through that hot pipe is all you got driving the big turbo on the bottom, so you want this channel to be as smooth and undisturbed as possible to attain max efficiency. I used a small air grinder attachment/compressor with an assortment of small stones to clean these up, making the inside of the hot pipe perfectly smooth. It would be interesting to see if they corrected this. Just for grins, I also ported and polished the ATS manifold, port matched the ATS with the head, the ATS with the secondary turbo, and the hot pipe with the primary. I enlarged the wastegate volutes just a little (hard to get in there), and polished the inside of everything. It all helped a lot. I hit 67lbs of boost pretty easy at the track and had to spend a good bit of time adjusting the wastegate to try and bring it down (no head studs). I currently sit at 63lbs on a WOT run. I would like to get them to stop somewhere between 58-60lbs. That is the top of their efficiency range not having an external gate.

 

Ok can you post a soundfile? I'm dying to hear what twins sound like!