oldmossback
Contributor
Matt,
I have three of the dacors, 2 R4's and a C3N..........the biggest problem I found with these regarding the lousy breathing was the 2nd stage. It is terrible! Blows air in many directions besides down the hose. The two attachment screw holes are linked with the so called venturi and air excapes up against the diaphgram. And the venturi is huge and misaligned to the intake horn. Some of the air hits the can wall.
Here are the things I did that helped improve the breathing. The two screw holes that hold the second stage to the can need to be tapped with a fine thread and two plugs inserted after the mounting screws are set. Use some wet suit glue to hold them in place.
The main opening is very wide and the uppper part blows against the can as I said above, you can soldier a piece of brass there to plug this big gapping hole and redrill with a 1/8 bit for a venturi style vent.......becareful not to damage the seat on the inside...and align the starting point for the drill bit thru the intake horn for more precise centering of the new venturi.....these two things will limit the air to just the venturi you create and the two vents on the back side of the 2nd stage..increases back pressure.....helps push more of the air down the hose...similar to the USD set up......
The second exhaust diaphgram on mine, I just tossed.....they were not useable......I just put in a duckvalve like the USD's use, You can use a long one from Dan at VSD as the horns are longer than the USD's........and put a little of the wetsuit glue around the rivet on the primary diaphgram, (both sides), to seal that possible leak off.........not to original spec's but it works. I put a long yoke on it and was able to use my banjo.
Anyway......hope this helps if you decide to make your units servicable......
Oldmossback
I have three of the dacors, 2 R4's and a C3N..........the biggest problem I found with these regarding the lousy breathing was the 2nd stage. It is terrible! Blows air in many directions besides down the hose. The two attachment screw holes are linked with the so called venturi and air excapes up against the diaphgram. And the venturi is huge and misaligned to the intake horn. Some of the air hits the can wall.
Here are the things I did that helped improve the breathing. The two screw holes that hold the second stage to the can need to be tapped with a fine thread and two plugs inserted after the mounting screws are set. Use some wet suit glue to hold them in place.
The main opening is very wide and the uppper part blows against the can as I said above, you can soldier a piece of brass there to plug this big gapping hole and redrill with a 1/8 bit for a venturi style vent.......becareful not to damage the seat on the inside...and align the starting point for the drill bit thru the intake horn for more precise centering of the new venturi.....these two things will limit the air to just the venturi you create and the two vents on the back side of the 2nd stage..increases back pressure.....helps push more of the air down the hose...similar to the USD set up......
The second exhaust diaphgram on mine, I just tossed.....they were not useable......I just put in a duckvalve like the USD's use, You can use a long one from Dan at VSD as the horns are longer than the USD's........and put a little of the wetsuit glue around the rivet on the primary diaphgram, (both sides), to seal that possible leak off.........not to original spec's but it works. I put a long yoke on it and was able to use my banjo.
Anyway......hope this helps if you decide to make your units servicable......
Oldmossback
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