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Chaparral1

Fastest 256 ssi

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Was wondering what top end speed you get with the 496 set up? I have the VP 5.7 (330hp) and max out at 38 knots. Is that about where it should be? Just replaced fuel pump ($$$) and awaiting weather to take for test spin. Am also curious if that will add a knot or two.

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Just a guess with 8.1L/496 375hp ... 50+ knots based on my larger, heavier, and overloaded boat reaching 43+ knots on a good day.

The first thing you could do, at no cost to you, is to load the boat right and trim the drive properly. Do you have the trim tabs on your boat?

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I bump 50 mph in my 220SSi with a 350 MAG/MPI when fully (heavy) loaded. I would expect similar or maybe slightly higher performance numbers in your boat with the bigger engine.

brick

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On my 265ssi with the merc 496 best I could get no matter what was 54.8 mph on gps. I tried everything but just couldn't hit that 55 mark.

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My 256 is bone stock. No trim tabs. I play with the outdrive trim switch to max out speed. 38 knots equates to 44 mph. The fuel pump was whining loudly and was hot to touch before replacing. Will see what I get now it's replaced.

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256 SSX, 496 HO Merc with some minor prop work, perfect air, lite load, and optimal sea conditions 63 MPH GPS.

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57.5 is my best top speed w/496. That was with just me, and running with the river current. In the early Spring, on my current lake, best I can get is 55-56. I also had my props lab finished but no other mods.

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57.5 is my best top speed w/496. That was with just me, and running with the river current. In the early Spring, on my current lake, best I can get is 55-56. I also had my props lab finished but no other mods.

Mine's about the same.....

.

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best I hae seen with volvo 8.1 is 52 mph. Funny as I get older my boats have spent a lot less time at full throttle. I have had this for two years now and I have pushed the throttle to the limit may 3 times.

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On my 265ssi with the merc 496 best I could get no matter what was 54.8 mph on gps. I tried everything but just couldn't hit that 55 mark.

Sorry... couldn't resist.

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Might be a silly question but...

Do trim tabs increase top end speed? I can see them aiding in getting some of the the hull out of the water however they're also creating drag.

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Might be a silly question but...

Do trim tabs increase top end speed? I can see them aiding in getting some of the the hull out of the water however they're also creating drag.

Tabs will scrub top end speed. For top end, you need to fully retract them. BTW, my top speed numbers are GPS speed, not speedometer. I've seen 60 on the speedo.

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I have a 2000 232.

5.0 L EFI

Pretty much only have max 30 gallons in the boat, along with 2 pair of ski's and 4 people with a combined weight (the people) of 750 lbs and

I can get to about 44 mph by speedometer.

I see most here are getting 50 +

Should I be getting more top speed ? Not sure of the pitch of my prop, but it is a standard prop, nothing special.

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Tabs will scrub top end speed. For top end, you need to fully retract them.

Although that my be a case here and there, especially with lighter boats, it is not an universal rule. It all depends on the boat and load. Mine performs better with the trim tabs partially deployed. Otherwise I would have to trim the drive in and waste too much of the propulsion force to raise the stern and level the boat. With trim tabs, they do the heavy lifting while drive trim is optimized to push the boat forward and not forward and up.

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2005 255 (cuddly cabin version of 256) with Volvo 8.1, no tabs, two adults, full tank of fuel, full water tank and fully loaded with gear hit 54.7 on GPS.

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Although that my be a case here and there, especially with lighter boats, it is not an universal rule. It all depends on the boat and load. Mine performs better with the trim tabs partially deployed. Otherwise I would have to trim the drive in and waste too much of the propulsion force to raise the stern and level the boat. With trim tabs, they do the heavy lifting while drive trim is optimized to push the boat forward and not forward and up.

Interesting

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There hasn't been a recent post on this topic. Time to declare this forums fastest 256 thus far. Couple guys touched 60 however the honor goes to Wingnut with a reported 63mph. That's definitely teary eyed stuff - even with shades. Still waiting on weather - waves were 3-4 today.

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There hasn't been a recent post on this topic. Time to declare this forums fastest 256 thus far. Couple guys touched 60 however the honor goes to Wingnut with a reported 63mph. That's definitely teary eyed stuff - even with shades. Still waiting on weather - waves were 3-4 today.

I've been in some really fast cats and pushing the go sticks forward at 125 is not for the faint of heart, but I was younger then and now anything over 65 in that 256 hull would not be something I would like to do. Mine is real light at WOT and in a confused sea, forget about it. One forum member went with a Pro-charger and got his 256 up to 73, but I would need a really flat bay to feel OK with that. Skater Boats were build in Baltimore and at the time they were super quick, with outboard power. The owner, founder was giving a demo ride out on the bay and stuffed in hard. His client survived but he was not so lucky. Taught me that confidence and luck are a constant balancing act. W

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I've been in some really fast cats and pushing the go sticks forward at 125 is not for the faint of heart, but I was younger then and now anything over 65 in that 256 hull would not be something I would like to do. Mine is real light at WOT and in a confused sea, forget about it. One forum member went with a Pro-charger and got his 256 up to 73, but I would need a really flat bay to feel OK with that. Skater Boats were build in Baltimore and at the time they were super quick, with outboard power. The owner, founder was giving a demo ride out on the bay and stuffed in hard. His client survived but he was not so lucky. Taught me that confidence and luck are a constant balancing act. W

I wish I could upgrade to the 496 HO but not worth the cost. I'd love to cross 60 in my boat. But like you Wing, I rode on my friend's Outerlimits 37 Stiletto. It has twin 600 SCi engines. Tops out at 93+. We did 85 when I was with him due to too much boat traffic and it was smooth as butter. I couldn't believe how the hull knifed thru cruiser wakes and other slop. I have a passion for "go fast" boats but they don't fit my lifestyle with 2 young daughters and a wife who doesn't like speed and noise!

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Top speed is over-rated. We typically cruise at 25 to 30 mph, and wakeboard at 15 (me) to 22 (son).

I only run up to WOT to check that all is running properly. Or if a storm is coming. Or if there is a Bayliner trying to pass me. Or if there is a boat full of girls. Or if I just feel like it...

brick

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