Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   dynoing with FULL wet exhaust?? (https://www.offshoreonly.com/forums/general-q/378250-dynoing-full-wet-exhaust.html)

Wildman_grafix 01-29-2023 05:29 PM

The guy I use always has all accessories on wet exhaust, water pumps, alternator etc.

I never looked real close but there is a Huge tank outside, pretty sure they recirculate the water.

Seems to me to be the way to get a true number, seen a pull the other day. The only thing the motor had on it was the recirculating water pump, dyno long tube dry headers no flame arrestor.

Would love to see the same motor ran both ways just to see how much the seawater pump, alternator, power steering pump makes a difference.


Long time ago Fountain did a comparison with a bunch of different exhaust. Was interesting.

articfriends 01-29-2023 08:38 PM


Originally Posted by MDG_Jason (Post 4857839)
We do run our dyno in full marine trim as it would be in the boat. Full wet exhaust, sea water pump, etc. We have numerous different header/manifold/tail pipes on hand from CMI and stainless marine with air fuel bungs in them, or we can run the customers supplied exhaust from the boat if need be. We feed the engine and dyno brake from a 1500 gallon reserve tank outside. With a garden hose refilling the tank we can run the dyno for about 30-40 minutes (give or take depending on engine load) while breaking in a engine at 3-4k rpm. Doing back to back pulls while dialing in a engine we will never run the tank dry. The exhaust shoots through the wall to outside. Because of our location noise could be an issue so we built a 5X8’ “room” outside that the exhaust dumps in to. The room has baffles in it and really suppresses the noise without adding any back pressure to the exhaust system

So WHERE did the water go, into the 5 x 8 room then down a drain? Thats my real question, diverting the water out in a way to catch it and not just blow it everywhere. I have dynoed with wet exhaust out the door with my old dyno, extended tails with 4 x 6 couplers into 6" pvc directed over barrels with sump pumps in them that sent water back to manifolds BUT this was a VERY rinky dink, messy m watery deal. So Im looking at PHYSICALLY how to direct water into something besides just blowing all over or on the ground as this will be in a new building with walls, etc, Thanks

MDG_Jason 01-29-2023 09:42 PM


Originally Posted by articfriends (Post 4857863)
So WHERE did the water go, into the 5 x 8 room then down a drain? Thats my real question, diverting the water out in a way to catch it and not just blow it everywhere. I have dynoed with wet exhaust out the door with my old dyno, extended tails with 4 x 6 couplers into 6" pvc directed over barrels with sump pumps in them that sent water back to manifolds BUT this was a VERY rinky dink, messy m watery deal. So Im looking at PHYSICALLY how to direct water into something besides just blowing all over or on the ground as this will be in a new building with walls, etc, Thanks

I understand, doesn’t sound like the way we do it is what you are looking to accomplish. The “room” is made of cinder block with openings in the base. All the water drains out the bottom. 5x8 building is on top of a concrete hill so it all naturally drains away from the main shop and eventually ends up in our gravel parking lot. All of it is our property so where the water ends up is not a major concern. Might not work in everyone’s situation, especially if containing the water is an issue. Maybe if said structure was water tight on the bottom with pumps to pump the water back in to the water supply tank

ICDEDPPL 01-29-2023 09:46 PM

I have in the past but forgot how we rigged it up.

I use a 50 gallon drum and recirculate water when I idle engines out of the boat it`s amazing how quickly that 50 gallons turns steaming hot.

articfriends 01-30-2023 08:50 AM

This is how I did it in past but going to engineer a better way, too temporary, too messy!​​​​​​

Prototype X 01-30-2023 09:07 AM

We ran a 250 gal tank setup at dyno shop for one of my engines and recirculated water. Like ICEDEDPPL said, the water heated up very quickly and it threw off setup/ HP #s due to warmer than running conditions water through intercooler. We ran hose water through cooler and picked up major HP and needed to jet accordingly.

snapmorgan 01-30-2023 10:02 AM

Where I dyno at has 2 huge simi truck mufflers on the opposite side of the wall at the back of the dyno. The mufflers are outside of the building with 5" stacks that go up past the roof. Every engine that they dyno are hooked to these mufflers with flex pipe of the same size as the header collector. The mufflers have a valve a ball valve at the bottom that are opened when doing wet exhaust to just let the water drain out of them onto the ground. The exhaust water is not recirculated. Works great, but it will deplete the storage tank eventually if you don't keep an eye on it. I will draw a quick picture and post it

snapmorgan 01-30-2023 10:09 AM

https://cimg3.ibsrv.net/gimg/www.off...9b5d833ed5.jpg

Wildman_grafix 01-30-2023 10:38 AM

That would be great to airbrush a SEMI on the side of the dyno building,,,,,, just saying.:drink:



Originally Posted by snapmorgan (Post 4857902)


snapmorgan 01-30-2023 11:43 AM

It is pretty cool to stand outside and listen to 1000hp being pulled.


All times are GMT -5. The time now is 03:32 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.