cheech

I second this motion.
By the time it's said and done you'll have a ton of money into it, (comparable to just buying a performance boat) and probably hard to resell boat.
Get you a west coast open bow style performance boat if you need the open bow.

This comes to mind with trying to make a Chaparral fast, even more so with Volvo Penta stuff.

87MirageIntruder

I'm one of the oddball guys that is into these 8.1s and modifying them for more HP. I can tell you it's difficult, as there aren't many parts options out there, and I'm working with the more common Mercury platform. It sounds like your drive might be a weak link too. Are you sure you want to go down this path? The boat you purchased looks like a great sporty comfortable cruiser as it sits.

And I can't leave anything alone either so I get it, but again are you sure with the boat you have you should mess with it?

Cap'm Kurt

yeah at that wot rpm, you couldn't swing a larger prop. It MAYBE would not loose much or any top end, but would feel like a dog. And that would load the heck out of the motor. Don't even think about it.

t500hps

Something else to consider and I don't know the answer..........some hulls just don't respond to extra HP. That boat was made to run comfortably and an extra 100-200 hp might not make it any faster. Even if that is not the case, 200 extra hp is needed to get roughly 10mph and the drive might not be able to handle that.

Dragracer_Art

Fair enough. I will leave it alone and maybe shop for a 2nd boat instead.

Dragracer_Art

Well I do know this hull goes alot slower with the 5.7 in it... like 8-10mph less than this big block. This is why I would not buy another underpowered boat. Already been down that road with previous boat.
Not even sure why Chaparral offered a 5.7 in this thing. I think anything 24+ft should have a big block in it.
That said... I think a Raylar 525hp kit will be more fun to drive than the current 375hp... even if it only gives me another 5mph... its still a gain.

the deep

iTrader: (8)

Yep, this is how the disease starts........... My disease metastasized in the form of a FourWinns 210 Horizon open bow family boat. A 383ci stroker making around 471hp, reglassed transom and raised x dimension 1 7/8, CMI headers and dry to the tip tails, nose cone on the OMC King Cobra lower...........boat ran 68mph radar on pretty nasty water. You see, just about all of us here have had the disease for some time. There is no cure.........................

articfriends

iTrader: (1)

Put a procharger on it with 3-5 psi of boost,, throw stock ecm in trash, retrofit a holley ecm and harness. Drive it till you break the drive, bux a imco SCX and hyd steering. I just dynoed a 540 with modded mpi intake that went in a 23 foot bravo 3 bow rider boat, made 710 ft lbs of tq and 655 hp, runs 67 with bravo 3 and 72 with bravo one xr (from what I was told)(guy switches them back and forth depending weather hes towing tubers or hauling ass). Build a 540 while the 496 is being beat up on for that day it pops, BTW, my friends wives call me MR B.I.G. (Bad influence guy).

Dragracer_Art

lol... Im that guy also. Always had one of the fastest cars or biggest engines. Been doing this stuff almost 40 years now. God only knows how much hard earned cash ive tossed into making horsepower for whatever I was building over the years. Last big dollar toy was a 70 Camaro with a Big Chief headed 632.
The boat will get more power eventually. Just havent decided how deep into it I want to go.
Safest route will be to just build a whole spare engine from scratch.
Since these 496's are already tall deck motors, it only makes sense to build a 572 or 598. Tons of off the shelf stuff available and easy combo to slap together. Also never had one before... so thats reason enough. Ive done 496's, a 511, 540, 565, 615 and last was the 632.
I also know enough to not hack up the boat to do this. I can/will transplant a very neat and clean OEM looking build.
I will obviously update with progress as it unfolds. Still in the permit process of getting a 30x40 2-story shop built. Once that is done, i can focus more on the next engine build.

Dragracer_Art

Yeah this boat is a keeper and probably the last one I will buy. It checks all our boxes and is why we drove from Atlanta to LOTO to buy it.
I will be "messing" with it for sure.