So.. I understand turbo vs super chargers...

To that end, turbo's add HP from 'free' exhaust pressure, and realistically, turbo lag on a boat should be no big deal, given that if you're punching it off the line, you'd be breaking lots of other parts anyway.

So, why is everyone bolting huge HP sucking pumps to engines vs. using a turbo?

I know boat MPG isn't a huge 'concern', just thinking on the surface a turbo makes more sense...

Just askin!

Specifically gas engines. It looks like there are marine turbo diesels.

thanks!

At the end of the day it probably comes down to return on investment.

Back in 2010 when Merc racing released the turbo QC4V engines, it was a significant investment wherein they invented a complete new wheel from the traditional SC platform.

Obviously, up to the 700, the SC performed and delivered with results favourable to the investment...and appealing to a broader end user audience as the SC works with bolt on exhaust systems Vs custom fitting to the turbo within the confines of the boats engine compartment.

Brad Smith (RIP) fabricated one of the most beautiful turbo instal's ever built - no comment on the sterling beast, but they both were complex and heavily engineered to make the systems hit target power.

SC intake, blower, strong fuel delivery is bolt on power within the intake valley if you can accept the extra vertical height. Not perfect in terms of heat and efficiency but effective for cost of components.

always comes back to money. Makes sense. Thanks.

I have done both plus big inch naturals, the big roots blower wins hands down next is big natural and last is turbos ,they will all make power but each has a unique personality and sound i also do not like the siren sound whipples make so its all down to what you personally like there all within a few mph of each other i love the big 16-71 polished blower with big carbs and a 4 inch wide blower belt its just mechanical beauty with a soft whir as they come to life... the exaust on a blower boat also has a sharp crackle to it with a spectator loving blower roll at idle its kinda like NHRAs pro mod there is naturals, turbos and blowers but the blower cars are the coolest most fun to watch.....i cant remember the famous t shirt but its something like turbos suck id rather be blown.....lol ..... my advice is do what turns you on if its none of the above then ur in the wrong sport....old school rocks the docks!

You can always add a blower surge button like ICDEDPPL did. lol.

I am a proponent of turbos, but like others have said each has its merits. This summer at Boyne Thunder, if you look at the newer boats you see most of them are running the Mercury Turbo engines. If the appeal of twisting a knob and cranking up your horsepower from 1300 to 1700 appeals to you, then turbos is where its at. Hardin Marine came up with a bolt on turbo kit for the 525, but it didn't get past the development stage. The stage 1 kit boosted hp from 525 to 775 and it was suppose to cost $12,999.95. The stage 2 kit boosted hp to 850. If you look at the performanceboats forum, you find a lot more turbos being used out west. Gale Banks was a huge pioneer of turbos and could get 1000 hp out of a 454 and have it be tame around the docks and very reliable. I think the biggest drawback to turbos on boats right now is no one is mass producing a kit. You can get a complete kit from CARSON BRUMMETT, but I would imagine its in the $15K range per engine, where as you can get a bolt on blower used for $3000.

https://www.speedonthewater.com/hard...-turbo-kits-2/

You have to keep the turbos/exhaust system cool in a boat. thats the biggest challenge

I ran a twin turbo set up for years dating back to my 1997 Checkmate. The first generation of the engine made 1200hp on 93 octane. I obviously couldn't make a bravo drive last so that 25' got sold and a 2001 30' with a single #6 went together. The last generation of that engine made 1730 hp on 110 octane and propelled that boat to 120 mph.

Heat.

The Mercury packages with turbo's are specifically designed with required specs on fresh air cooling/venting. And they have their own cooling methods.
Some turbos are even using water cooling.

But the heat in the enclosed engine/bilge compartment is always something that has to be dealt with, and can literally melt down other parts. The other parts on the engines are not designed for that sustained heat within the bilge.
Mercury started from scratch to engineer their components for such.

That's why you see turbos so prevalent in drag racing, but not road racing. Add on turbos are great for bolt-on simple short bursts of added HP. But they are not so great for sustained high boost and high RPMs UNLESS the entire vehicle was designed for such from scratch.

Agree, heat, heat, heat. As a ground up design build mercury racing was able to water jacket virtually everything hot. As a retrofit to a say 525 it would be so tough to contain the heat. Long term everything with a water jacket...rots. So just bolt on that whipple or procharger and go boating........