Jet maniac lay down pipe water box


Site Supporter
Needed a new water box for my rrp pipe. After looking at a few different ones and seeing a jetmaniac laydown water box in Daytona I had to have one. The build quality is perfect. I also like the shape and size of it, it fits really nice in my ski. Another positive is how quiet it is compared to the rrp box it replaced. I'm running an unrestricted waterline to the water box and it isn't much louder than a superjet with a b pipe. Even with that much water running to the water box it preforms great and it dose a great job of keeping water out of the motor. 10/10 received_1061004800945691.jpeg
Love my jm waterbox but my neighbors hate it. I got threats so I I tried a ss 2.25 in line silencer off ebay in conjunction and problem solved. Might be useful for someone. Btw multi million dollar homes on canal we ride.


  • 20200611_114918.jpg
    58.4 KB · Views: 105
  • 20200611_114929.jpg
    52.9 KB · Views: 91
Adding another positive review to this thread. I just had a chance to test my JM laydown box in Daytona. I swapped from an RRP box also after reading about the problems with water ingestion, not to mention noise.

After the ski sat on shore with waves crashing into the rear, and then lifting the rear to drag it into the water (waves still hitting), zero water found it's way around to the engine.

Another note: even though you need to have a reducer to go from RRP chamber into the JM waterbox, you are not restricting exhaust flow because the ID of the RRP chamber is less than 2" since the walls are so thick.


  • IMG_1033.JPG
    183 KB · Views: 79


if it aint broke, dont fix it
St. Clair, MI
Finally installed my JM box into my DVX with an SS900, ran the JM and original PFP box back to back, both @clouse22 and I rode a tank through each and the results were better than expected, forgot the gopro at home so I didn't get to record the sound difference, definitely not louder but gives it an even deeper almost 1200 like tone which I love. The big surprise was the performance, with the pfp box my setup had crazy low end off idle but when doing a flip it was as if the power signed off towards the top end, switching to the JM box seemed to have moved the power further up the RPM range and the ski definitely pulled harder riding up the wave, im sure I could still make some pitch changes on my prop to assist but for what I'm trying to do, im very pleased with this result, next ride I will be installing temp strips on both boxes and retesting, the pfp holds a significant amount of water even after being "brapped out" while the jm box seems to empty the little bit it holds on the first throttle snap out of water.

Overall I'm very impressed with the JM box and can't wait to do some more experimenting when the weather breaks.

Sent from my SM-G973U using Tapatalk
Top Bottom