Many days I try to use my brain like a random number generator for ideas that result in blog entries. Lots of times that leads me down interesting rabbit holes, sometimes it leads me down dead ends, and at times like this it leads to me to a place I never knew existed. Perhaps this is old hat to you boat guys but I was pretty blown away to see that someone had actually built a rig to dyno a boat with the engine still in the actual boat that is being tested. By now you have looked at the image above and thought, “WOW!” or you have thought, “Yeah, guys have been doing this for like 50 years.” Either way, this was the neatest thing I found when I typed “boat dyno” into the YouTube search engine.
Developed in New Zealand as a joint venture between the tuning shop NZ-EFI and Harris Marine it is pretty ingenious way to get the testing simulation and power numbers that owners want without having to pull the engine out of the boat and reload it once the job is done. The boat sits on the trailer and a few pieces of the jet unit are removed. Once the bowl and impeller are removed an adapter hooks the boat to the driveshaft that turns the automotive differential on the actual dyno unit. The guys admit the obvious that there is some power loss in having to turn the diff but the reality is that even with the lower numbers than you’d get on an engine dyno, this is an awesome way to actually race tune your boat with it living in the boat itself. Being able to control the loads on the engine and all of that are a huge advantage to tuning the making sure the mechanical end of the boat is happy. We think this is a spectacular idea and it is pretty freakish to watch, right?
Ever seen anything like this before? We sure haven’t!
Interesting use of a wheel dyno. These generally use Eddy current power absorbtion units (PAUs) though I can’t tell much from the pics. My question is “What do they use for engine cooling water?” Seems like it would take a lake of water to keep that engine happy.
All in all, an interesting deal.
Dan
From what I have had reported to me the cooling setup by NZEFI on this rig runs a ‘total-loss’ system. Adaption couplings feed in cooling water taken from the buildings ‘mains’ supply. Note the various green hoses leading to/from jetboat.
(Minimum New Zealand water mains flow is 25L/min for ref.)
This appears to be a Dynapak, which has hydraulic PAUs. We’ve got one in our shop.
Yep there DynaPack 3000-series modular type absorption units (‘hub dynos’)
(invented in New Zealand)
On a ‘Jet-Boat-Dyno’
(invented in New Zealand)
Recording data from a jet-boat
(also a New Zealand invention)
sorry, the patriot in me couldn’t resist 😉
Just put on a front axle, wheels and steering and you’ve got a hot car/boat…