KAAMA

I agree with 26Scarab---naturally aspirated is a much better way to go in my opinion. Less parts, less pulleys, much easier on parts, less maintenance, less of a chance of something to go wrong, more fuel efficient. I would opt to just build larger cubic inches over a blower. It also depends on how much $$$ you're willing to spend too. If I had an Apache then I would perhaps consider supercharging an engine because it takes bit power to move one of those dudes...but I would always consider a LARGER NA engine first. $$$ and the priorities you have with it usually is a major factor and at the top of the list when considering all this stuff.---basically, it's how much you can afford and how much you're willling to lose if something goes wrong I guess.

WETTE VETTE

How much parasitic HP is used to turn the blower and make the boost? I know it will vary. If there are 2 motors making 700 HP at the crank, 1 N/A and 1 W/ a 250 blower at say 6 LBS of boost. Does it take 50 HP to run the blower? Will the blower motor essentially be working harder to get equal crank HP as a naturally aspirated motor? I know this is way extreme, but I once heard on top fuel drag motors it takes about 800 HP to turn the blower at max rpm. Just curious to see if anyone has any data on some of the blowers used on boat motors.
Thanks

jdnca1

I also feel that the torque (down low) of blower motors KILLS bravo's. I run a Natural 632 that makes 900hp and 806TQ....(but not killer TQ in the mid range) so far have only broken 1 drive...when it was "new", set up too loose. Anyway, I'm sure I'll break one now since I posted that. But if you can make as much power for less cost and complexity, while helping your already "strung out" bravo, I don't see the need for a blower. You really need to do your homework for the right hardware combination and find an experienced engine builder to make the NA set-up sing.

KAAMA

Yes, I forgot to mention (directly) the effects of a supercharger on an outdrive...especially a Bravo!!! I think you would greatly shorten the life of a Bravo One drive...maybe not right away but eventually with a supercharged engine where the torque comes on like GANG BUSTERS!!!...and-----UT-OH!

26scarab

Kaama ,
I was waiting for you to help me out !

I totally agree with what Kaama , WetteVette, and Jdnca say about Blower motors.
I actually thought I had a pretty good combination until I heard about Kaama's 680hp with a hyd. roller cam, yeah baby ..no more lashing valves !!

Blowers, we don't need no stinking blowers !!!!!

Now if I had a 47 Apache with triples it would have the biggest displacement motors and the biggest blowers I could find sticking out of the hatch !!!

Although a trio of 632's with Big Chiefs and sheet metal tunnel rams would look killer too

KAAMA

Actually, my dyno sheets said my 540's made 699HP @5750rpm....but I don't think I want to turn them that high. The highest I want to turn them is 5500rpm ---they make 682hp at that rpm which is good enough for me.

WETTE VETTE

KAAMA, Scarab,
You guys are both putting out some real nice HP numbers. It makes me wonder what my 496 is putting out. I guess it doesn't really matter since my boat is running better than I had ever hoped, but it would be nice to know. I always assume 700 plus as a conservative estimate. Maybe someday I will take a ride to Grand Rapids and throw it on the dyno.