JSRE Dry Stacking The Mercury V6

Dry Stacking Exhaust on a Mercury V6
Article by Jay Smith of JSRE
1.11.02

What is Dry Stacking?

Dry Stack is a term relevant to the cascading of water from above in the exhaust system, which is diverted over the tuner to cool it and to lessen noise.
The increase in acceleration and power this system creates is noticeable. When the water is diverted (the JSRE system diverts water through stainless steel tubing to the water pump area to keep the added heat from burning the water pump) away from the tuner exit, the tuner is now pulsing nothing but exhaust gas – not water. As water is heavier than air, the water hinders the strong scavenging effect, and the exhaust gas pulse is weakened by the specific gravity of water vs. air. When the water is diverted around the tuner, the tuner is left to create its strongest pulse, since it is not lifting the heavy water at the tuner exit. This where you get the power increase. The increase in heat in the downhousing area is negated on the JSRE system by the tiny diverter holes that route a cool bath of water directly on the down housing to prevent over heating and stopping the normal "chalky and dull " look that the added heat can result in on some methods of dry stacking.

	1. Two holes are drilled and tapped to accept a stainless steel 1/4" npt X 1/4” tubing straight adapter, and threaded in securely with J.B. Weld epoxy on the threads. Epoxy all other small holes in the top of this area at this time.

	2. 1/4" stainless steel Tubing is cut two inches longer than the exit of the tuner and the tubing is "set" in the fittings with the addition of red Loctite on the threads of the tubing adapter. I made a special tool since we perform this modification on a daily basis. I make tools that make the job less labor and nerve intensive. The tool is a sacrificial end wrench and a 9/16" deep socket that has been heli-arced together so the stainless steel tubing will pass through the socket and the fitting may be tightened securely.

	3. After the tubing is made up I drill a single 1/16" hole in each of the stainless steel tubes at the top of the tuner flange at about a 30-degree downward angle. This bathes the down housing with water and prevents chalking and blistering of the midsection.

	4. With a wood mallet, I shape the tubing along the curvature of the tuner, ‘hugging’ it tightly. I have machined two saddles out of 6061-billet aluminum with a slot where the tubing can pass, however, the saddle holds it firmly to the tuner with a weld. If this step is left out, the tubing will harmonically break at the fitting or the 1/16" hole that was drilled.

	5. Next, two holes are drilled on each side of the spent water cavity and tap to 1/4" npt. I install a 1/4" npt X 3/8" hose adapter with Loctite applied to the threads and tighten it looking backwards. Then attach approximately 1 1/2' of 3/8" fuel hose and trim to the desired length when it is installed. The last step is to use a pair of tubing cutters to trim the tubing to where both pieces are 1/2" lower than the lowest outlet of the tuner. After the cut take a pair of pliers and squeeze the end of the cut to a "fan" shape. That’s so the pressurized water going through the tubing is not sprayed off the water pump and back up into the tuner. You also get a more even spray of water on your pump.

	The finished product, ready for installation into the engine midsection.