Poor mans RRP pipe (wet, dry pipe)

[Quinc]

Anyone currently doing this; how have your results been?

• Any tips on sprayer location: pre/post coupler
• Sprayer restriction jet sizes 701-760cc 80-90
• Dual 38/44 jetting/pop off changes
• impeller/pump changes

My current setup. Testing went ok. Bottom end was there but no where near as crisp as when it had the bpipe. Going to try restricting the water to a 80 or 90 jet. Then switching to my freestyle impeller.

Old Coffman dry pipe. I added a sprayer with 130 low jet after the coupler.
62t/61x
MSD enhancer
dual freshly rebuilt 38's (no choke, 1 screen) stock flame arrestor
75P
140H
34psi pop off (really not sure where to start here, have read from keeping it at the stock 55psi to as low as 24psi)
Trying a solas 14-18 impeller until I get my Solas 13/15(similar to hooker 9/15) back from impros.






Sprayer being used tapped for mikuni jets.

@Jetfiend @Harbor @Aquaholic @waxhead @Big Kahuna @Jr. @john zigler

 

[Big Kahuna]

How do you have the pipe plumbed up? Is it plumbed like it should and you are adding water to bring in more bottom? Or are you trying to run entire pipe with just spray bar cooling?

 

[Quinc]

How do you have the pipe plumbed up? Is it plumbed like it should and you are adding water to bring in more bottom? Or are you trying to run entire pipe with just spray bar cooling?

Right now I am running it like it should be ran with the sprayer added to it. (water going through water jacket) Figured I would start out safe and not chance melting a coupler until my spare comes in the mail. With the water coming off the head to the jacket it should keep the pipe temp up.

 

[Big Kahuna]

If you have it routed like it suppose to be, then adding water will not damage. I would go with smallest jet and see how it runs. Then start stepping up and see what feels the best. It can either get better or worse.

 

[Harbor]

My type 4 was drilled before the coupler and into manifold, slit sprayer like you have, no jet, and ewci to shut it off, helped bottom end some but kept the crazy dry pipe acceleration & top end.

Later the water soliniod broke, so it was continues injection, never had good bottom end, then the pipes inner shell cracked and it lost the crazy top end.. b- pipe was hands down better bottom end. Never ever came close to that with that dry pipe injected. At its peak with control it was lazy down low and a 2 second lag, but accelerated scary fast.

If you drill the manifold you can plug off the water jacket so the pipe can heat up and run just the sprayer water but prolly need to cut that slit off so it cools the coupler or get the straight sprayer, Right now the pipe can't heat up..

Have you pressure tested that pipe? Seems like it would best ran as a controlled dry pipe.

On my RRP I run between a 60 jet and 110... 110 best down low and 60 less bottom more top.. pipe heats up 140 to 179 respectively

Jetting on 38's was like yours, I'll see if I still have the pop off in my notes.

Now that I think about it, my type 4 boat had a tall pop for running bouys so maybe it could have been better with a low end prop..

Pf pipes when ran wet and before the innermost chamber is removed, have no water ran to outer water jacket, just a spray bar in manifold, but make noticeable bottom end, so much so that some dry pipe riders don't like it, to jerky down low..

Ill pm you

 

[Half flip95]

when set up correctly, the dry pipe will make more power everywhere... problematic in other ways but they definitely make more power. I would rethink what exactly you are trying to accomplish. what you have here is a water jacketed wet pipe. pipes work better when they are hot