Hey, gonracn...

[deerfield]

How hard would it be to put a turbo charger on the 325 engine? What would be involved? Any modification required or straight bolt on application? How much might it cost? Any downside to adding boost to an engine? Would the additional horsepower result in additional top end speed?

Saw on another thread that you race cars and figure you might know something about this. - Deerfield

[sandm]

edit-you're talking boat engines.. duh....


personally, I would not even talk turbo on a boat engine in the enclosed compartment it sits in. turbo's generate a TON of heat and with nowhere to place an intercooler with sufficient airflow, you will be inviting trouble with both overheating and reliability issues imo. a single turbo would need quite a bit of exhaust piping added, reprogrammed ecu, larger injectors and airflow to feed the turbo. keep in mind that most turbos need 2500-3000rpm's to "spin up" and start producing hp. most wakeboats run out over 4k. I would also think the added shock to the tranny/vdrive once a turbo spools up would not be good for their life expectancy.

a centrifugial supercharger would be a different way to go, as they can sometimes make power across a larger rpm range, meaning more power down low where you want it, don't generate the heat a turbo does, usually run a lower psi meaning potentially less bolt-on's needed and lower chance for detonation(death to a motor), and can be added to a smallblock engine in 4-5hrs.

I don't know much about superchargers other than that, but I would not even walk down the turbo path if it was my boat.. the performance boat guys run a lot of blown boats, but they have engines with super-low compression designed for high-hp applications and have engines designed to run a much higher rpm than ours, and in most cases you are spending most of your day in the low-mid rpm band of your engine where a blown boat wouldn't want to run

interesting question.. reasoning?

[bzubke1]

Turbo or really any type of performance upgrade is in my opinion not a good idea for a boat like ours. I know from experience with cars that once you start messing with the internals of the engine or boost it makes things less reliable that it was in stock form.

On a side note it would be pretty awesome to get an old direct drive ski boat and do something like this. I want to someday get an old ski nautique 2001 or 80's supra sunsport and put a cummins 12 valve in it if its even possible.

[gonracn]

They have taken the words right out of my mouth.....

[kaneboats]

I've skied behind a 25 HP outboard on a wooden boat (it has been a few years though). It kills me when you guys think 310-325 isn't enough on a boat that's probably lighter than that old wooden one was.

[maxpower220]

Turbos are fun, especially if you can build an engine to handle 25-30 psi of boost. However, it takes a lot of plumbing of hoses, space and cooling for an intercooler, and the venting of heat. Not really a good place to do it on a boat. Also, the function of the boat's engine also isn't well used for a turbo application when compared to supercharging.

Modern supercharger do a similar act as the turbo, but usually can be done in a smaller area. Also, the power response would be a little better in a tow boat application. In a drag boat, turbo all the way.

Either a turbo or a SC could be added safely to a 325 with about 3-5 psi of boost with no internal mods. However, you will need to alter the timing and fuel management to deal with the boost. Why not look at a new MasterCraft with an Ilmor engine?

[sandm]

how about a 100shot of nawssss. just about the time that skier yells "hit it" and you really do

[deerfield]

I've skied behind a 25 HP outboard on a wooden boat (it has been a few years though). It kills me when you guys think 310-325 isn't enough on a boat that's probably lighter than that old wooden one was.

kane - I agree. A 325 in my Outback is plenty. As with your experience, my pop taught me to ski behind his Starcraft fishing boat with an 18 hp Johnson. Here's where I'm coming from. I was thinking about things that I could do to my boat. But eveyrthing I thought of I can pretty much eliminate cause someone has already done it (e.g. audio and wraps) and I really pretty much like my Outback just the way it is. So why spend the money. Even the swim paltform has the original black traction pad from the factory. Works fine. Then I got to thinking that from time to time I take my boat out on Lake Michigan where there is flat water for miles (on the right day) or find myself in the vicinity of a guy with a fast boat, and what it would be like to flip a switch and be able to go like the wind, hit 60 or 70 MPH. I think it would be cool to have a "sleeper" boat. It's not something that I've heard any Moomba or Supra owneer yet do to his boat. But, having read the above from people who know about turbo and super charging, I guess there is a good reason why. I remember riding with a guy in his off shore boat and loved the speed and sound of the engines. - Deerfield

[maxpower220]

Regardless of what you do to the engine, your enemy will be the hull. All hulls are built for a function, ours are built for a wake at 36 mph. Most Outbacks are topping out at @45 mph (give or take 1-2 mph). As speed increases, so does the friction on the hull (per the way it is designed). Check the Nautique forums for speed issues. Trying to break 55mph in an Outback would probably require more than a turbo and may be nearly impossible.

Even the Python (496/502 cid) motors used by CC in 196 were only in the low to mid 50s.

[lsvboombox]

I wonder what this wake boat tops out at? its got twin turbos on a lexus v8... 550hp

http://www.luxmarine.com.au/Wake_Ski...or_V-Drive.php