Turbos and centrifugals
 

Curious. I see lots of guys loving turbos and centrifugals these days. I have never driven either of them in rough water.

How do they perform when say you are running hard in big water and on/off the throttles ?

I would think Mild in comparison to big roots Thunder!!! :angry-smiley-044:

Gentry Loved turbos!!! He seemed to do ok! :drink:

In and out of the water, I'd say Positive Displacement Superchargers.

I just bought a set of Gentry Twin Turbos for my next project. Never ran them before, but always wanted to ever since I saw my first Gale Banks setup at the lake years ago. (this endorsement may change later! haha!)

I like Superchargers, but they eat horsepower to make horsepower. More boost, more horsepower, kind of a "Catch 22". Blowers also stick up, particularly with innercoolers, which make hatch mods a given. They're sexy, but kind of big and bulky.

Turbos (apart from a minor exhaust restriction) is free boost. I like the turbos in the marine environment (turbo application to turbo application---not as a comparison to other types) because the throttle use is less (no stop, start, stop, etc.) and a marine engines are always in load, which keeps a positive "spin" on the turbo. Even Merc is moving that way on some of their engines, granted probable because of packaging, but still, the right turbo set up and you can make lots of horses, and still have your lady a place to sun!!!

Centrifugals, I actually bought a set of ProChargers, but changed direction when I found the Gentry's. They are a mixture of both, good packaging, but burn some horses to make horses. What changed my mind about the centrifugals was the noise. I know you can get the helicut gears to help the noise, but most of the folks I talked with said they rattled and whined at idle. I YouTubed some centrifugals and the whine was high-pitched and annoying (to me anyway)

I still have the ProChargers if your interested, will make you a good deal! :)

I have both, well sorta, run procharger on the checkmate, works very well, and even in rough water working the throttle is fine, we drag race a turbo LS car, which also works great but in the rough water in and out of the throttle the blower will work better I think as you get your boost right back and the turbo will lag a bit on most setups..

Nothing is free, or even close to it. If you have ever put on an exhaust back pressure gauge on you would realize this. Back pressure will ALWAYS exceed boost pressure, otherwise the turbine won't drive the compressor. The back pressure reduces efficiency and robs you of power the same way the blower looses through parasitic loss, although at larger power/boost levels the turbo does have an efficiency advantage.

Word. ^^^^^ No free lunch in energy.

A/R ratios make this not necessarily true, wrto back pressure vs manifold pressure. Makes tuning on EGR systems for diesels sometimes interesting.
Turbos are the most efficient because they are largely driven by the heat energy from the expanding exhaust gases that are normally just wasted. Though they do increase pumping losses. No free lunch, but turbos are closest!

The turbo vs procharger is the best head to head , the roots takes you into weight ,height how much zest the snout of the crankshaft has and so on . Good wastgates in a boat twin turbo set up wont have your passengers getting off after a ride saying "yea its fast ,but the lazy throttle response was kind of dissapointing"
But you have spent a ton of money on alloy water cooled exhaust components and intercoolers ,plumbing ect
Even the jet skii crowd tends to lean towards mini procharger and eatons to get some pretty stout hp out of little 1500cc motors and such ,with no driveline comprimise issues . Cept honda of course , with their auqatrax turbo
But when you have a minivan motor in a outboard selling for 20k+ you can go outside the box here and thers