Question about dry exhaust???
 

Does anyone on here run dry exhaust in their boat? If so how much louder is it than when you dump water into it? Over the winter I had my mufflers removed and my exhaust converted over to dry pipes. The water actually exits through the outside of the pipe through a 1 1/8" diameter hole. Is that hole going to be sufficient enought to not create a back pressure? I haven't installed the pipes yet. I hope this makes sense...maybe I can post some pics of it later.

Re: Question about dry exhaust???
 

If your question is will you be making friends out on the water then the answer is NO!! If you are wondering if you will have problems with reversion then also the answer is no. If you are talking about the 1 1/8" hole being enough to not have high water preasure it seems like it would be to small. You may want to put a by pass in there. Most of the other boats that I have seen like that have them.

Jon

Re: Question about dry exhaust???
 

What kind of a bypass and were would I put/rig them? I am running 525's with closed cooling so I don't know if that makes any kind of difference. I also have pressure relief valves on my sea strainers.

Re: Question about dry exhaust???
 

Its done all the time ....but wiil be ALOT louder ... I would assume the pipes were designed to flow enough water but you motor might dictate how much water flow you need .. My pipes are "wet" to the end ....Then exits into the exhaust flow ....The small V at the bottom of the pic makes a Spray Pattern that the exhaust passes thru ....Not sure if that is for cooling the exhaust or Sound ...They are Stainless marine ........m

Re: Question about dry exhaust???
 

I run full dry CMI headers and pipes. The water and exhaust doesnt mix at all. The water dumps out of bungs ( I guess about 1" or so ) welded to the tails and thru the transom by a thru hull fitting. I have no by-pass valves nor do I have any pressure problems. Much like your 525's, I run closed cooling. The down side, they were very loud, too loud. At the time, GGB was still around. I got a set of their Extreme mufflers. They made a big difference. Its still loud, but its bareable. The best part, no power loss at all after adding the mufflers. Too bad they are out of business. :mad:

Re: Question about dry exhaust???
 

ask Drypipetiger or pm him. Twin 700 dry... twin 700 loud.

Re: Question about dry exhaust???
 

O.K. here's a couple pics of the exhaust. I remeasured the hole and it is 1" not 1 1/8''. The smaller hole that you see insde that is for securing the slip in Gattlin mufflers. I'm no expert here but I'm a little concerned that the exit hole for the water is not big enough and will create too much water back pressure. The people at IMCO (who made the pipes) and Eliminator say it will be fine and thats how they used to do it on the race boats. Any input would be appreciated.

Re: Question about dry exhaust???
 

A buddy had a fountain with stock 550 EFI's and dry pipes.....loudest dam thing I ever heard. We did a poker run on the boat with him a couple years ago and my ears were ringing the entire night and most of the next day.

Re: Question about dry exhaust???
 

dry pipes are significantly louder. LOUD. it appears as if there is a bung missing from the large hole in the tail pipe. typicly it would have a bung with a 3/4 pipe thread in it to plumb to a dump or thru hull. also the smaller hole should be on the top of the pipe when it exits the transom to get rid of the chance of having a hot spot due to an air pocket.
take another pic.

Re: Question about dry exhaust???
 

Why would you put a bung in it and plumb it throught the hull? Now I'm completely confused. The water is going to dump through that hole and thats it.