soldier4402

Sold the fountain and now into a Chaparral 265SSi, not performance i know . Anyways boat weighs 5200 dry, has the volvo GXI motor which is a 320hp 5.7 red motor. Boat mechanically is in great condition had it checked out. I dont know much about the duo props. Current its sitting on the F4 duo props. Boat pegs out at 5200 and gets me to about 42mph GPS verified. I have bottom paint thats a little rough, so that might be hurting a little bit. But listening to the motor you can definitely tell its reving higher and not producing the power. I tried talking to some Chappy guys on their forum, great guys but their knowledge was more basic. From what I gathered with that prop on these boats 5200rpm is right and lower speeds is prevelent. Im just wondering for more speed whether going higher or lower in the F props would work, should I go F6 to faster or F3 etc? That SSi is a deep boat, and loaded probably is a 6000k boat. But still thinking it should be high 40s boat.


On a side note, boat has the switch for captains call but the system wasnt installed. Besides corsa where could you find a system that would fit. Corsa wanted over 2 grand for theirs and not really looking to spend that, was looking to spend half of that.

Knot 4 Me

For a reference, I have a Chaparral 260 SSi (open bow version of your boat) with a 496 MAG/Bravo III. These boats are every bit of 6K lbs. with gear/fuel/water as my old 6K lb. Poly Lift would barely raise my boat if it was full of fuel (moved to an 8K lb. and all good now). The best I have ever seen GPS with my old 26" 3 x 3 propset was 54 MPH GPS. Most days the boat will run 50 - 52 MPH GPS with a 25" XR propset (4 blade forward, 3 blade rear). Only install the Corsa if you want noise. They are side exit systems on these boats and have zero effect on WOT RPM/speed. They have to turn back towards the front of the boat to exit out the side. Not very efficient at all. If your props are in good shape and you are turning the proper RPM at WOT I would focus on the bottom. If you don't need bottom paint I would look to remove it. I bet you'll pick up 2 - 4 MPH depending how bad it is.

BUP

iTrader: (9)

With the Volvo and they have a Service Bulletin about installing the silent choice / captions call exhaust. They recommend Corsa because they should have the correct crossover for the Volvo . You need this crossover because it helps prevent water reversion - the crossover equalizes exhaust pulses to help aid against WR. With installing silent choice you maybe will see - GPS 1 to 3 mph at the very best and 3 mph if you go to church every Sunday and pray for it. I have installed this set up from Corsa many of times as well for the Volvo apps using the Volvo stock Exhaust manifolds & risers. You have a small block and it does not have the torque to push a heavy boat like a big block has. Plus Chap boats are not fast in the speed department.

Also Volvo outdrives use a GL5 gear oil - do not use any Merc gear oil in a Volvo outdrive. Volvo has a coating on the cone clutch (Nedox coating) and certain gear oils will glaze and or form deposits on it, causing shifting problems. I know this for a fact - OEM factory Volvo Penta trained every stinkin year since mid 90's to currently.

soldier4402

Thanks for the info so far.

Knot for me Im guessing that 496 was probably good for another 5mph or so. even with the GXI, im still thinking Is should be 45-50mph with proper props. Bottom im guessing is a little hold up, taking it all the way off probably isnt option, but sanding it down and redoing it might work.

Im just wondering if moving up to say an F4 ro F5 would better.

High Cetane

I have a spare set of near-0 hours F5's I'm selling if interested.

BUP

iTrader: (9)

forgot I just did a 496 Volvo Corsa install 2 months ago and took some pics. I can email you the pics of the install if you like. The owner has been using the boat 3 or 4 times a week since with no problems of water reversion but again, I used the what Volvo / Corsa has recommended. I know at first Volvo had some problems with water reversion without the cross over when captions call / silent choice was installed. Stock Volvo's do not use Flapper valves / water shutters in their exhaust set up like stock Mercruisers. . They got rid of them in 1999 and have a service bulletin about that as well. .

High Cetane

Without the crossover, an 8.1 will (eventually) inhale water. The crossover is for balancing out the vacuum created in the exhaust on a particular bank during shutdown.
I wouldnt bother at all with the Corsa..agree, no perfomance to be gained..just noise.

soldier4402

how much you want for them

Knot 4 Me

No crossover on my 496 factory Corsa setup, 400 hours and no reversion. Then again Merc's Gil-type manifolds/risers are different than the cast iron stuff on a Volvo 8.1L. The side exists have silicone-booted stainless flappers. There are also baffles in the staniless elbows that are between the tubing off the risers and the tubing from the tips.

Pray whomever had the boat before you regularly pulled those props and greased the propshaft splines. Especially if the boat was ever ran in salt water. Those props are notorious for welding themselves onto the shafts.

Get the bottom cleaned up then mess with props.

soldier4402

No I agree and look its not performance boat. But a rumble would be nice. And I was thinking if the system was cheap enough new, or could find a used one. But for 2k it doesnt make sense.