4195

Okay I need a new project to get through the winter, so I am taking my motors out to repaint my bilge and want to freshen them up. But as long as they where out I figured I should bump up the horse power a bit. A little back ground on how it runs now. The current motors are 550hp. I am spinning a 26 labbed prop at 5400rpms best gps. is 79mph but the boat will run 76mph everyday. So one choice is to change the heads and match port intake and heads add a bigger cam and carb. The motor builder said this would get me close to 625hp. Option two would be freshen everything up but bolt on a set of Prochargers. With the charger running 5lbs of boost I should be in the 650 hp range. The charger benefit would be I would be able to run a 30p prop which would improve my cruising speed greatly and then have the power when needed. There is not a big price difference either. I use the boat in the ocean and at times it can rough and snotty, so I am wondering if the procharger would be harder on the motor and drive when coming in and out of the water? So let's hear some thoughts....

CIG3

Go N/A. With the right combination you will be much happier and have motors that will live for a long time. Superchargers create heat and heat kills motors. If you were looking for 750HP then superchargers are a better cost reducer than building 540 or 572's.

There are a few threads out there from guys that have really nice combinations for the HP range you are look for.

My $.02

Magic Medicine

I would stay with NA for the ease of tuning. In my opinion, there aren't to many guys out there that can "properly" tune prochargers. If you need boost I would go a different route.

Uncle Dave

Go high quality NA maybe switch to injection.

With a new top end and exhaust system you can be a real happy guy.

Stay away from the air pushing stuff unless you are going to commit to a total low end rebuild as well and then budget double for tuning.

Youll be "chasing" procharger problems the rest of your life unless you send both engines to someone thats done it before in a marine environment.

Uncle Dave

4195

These have been my concerns. Either route I think I am going to the guys who built my current motors they are a Procharger dealer and would test and tune them on the dyno. I was really thinking of going n/a but they are the ones that said this was another good direction to go.....

chewymalone

I agree with the statements that a professional install from a true marine builder is the only way to go with S/C's. That said, I think your estimate of making 650HP at 5psi is way low given that your motors are already making 550HP. You should be able to easilly make 750-800HP without outrageous boost numbers.

I have 500 EFI's with Vortech's running probably 5-6 psi and making 700HP. I can drop a couple of pulleys down and make 825HP. Mine behave great at all speeds and are trouble free. Again, they were installed and tuned by Ocean Performance... not Shadetree Jimmy. Just giving another perspective.

Uncle Dave

Let say you bump the mill one way or the other - ok.

What kind of steering and drive setup do you have-do you have tabs?

You may have more to do than just the engines...




UD

thisistank

Here's the real question....Are you ready to buy new drives all the time??

Bravos don't like that much power to 'em...Especially when on a heavy Cig.

And with that said...I'd go N/A over Pro-Charger all day long....And I'd go Whipple before Pro-Charger....But that's just me.

CIG3

What Tank said....

4195

Okay I have gotten some of the responses I that thought I would, do how about one more option. How about a 250 Blower Shop blower. Or would I be better off with n/a still?