Sweet 16 Top speed?

[woobs]

According to the chart it is a 1:51 OMC cobra drive, Chevy was a late year offering. I had an early 90 16 it had the Ford 302 same ratio drive, nice thing is a SBC will bolt RIGHT in an give it some real GO!

With a 1.5:1 drive and a 21* prop, at 4,800 rpm and 10% slip... you get 57.3 mph on Lake Abacus. Looks like there's some prop work to do after all.

21	x	4,800	=	100,800.00	=	63.6		0.9		57.3
1.5	x	1,056	1,584.00

[mattyboy]

As I read the chart the 4.3 is 1.68 overall not 1.5.

find it hard to believe that a 190 hp v 6 is going to turn a 21 to 4700 rpms on 1.5 gears it does take 1.5 litres of oil

4700 on a 1.68 with a 21 pitch and 50 mph is dead nutz on at 10% slip

[woobs]

Matty,

Your number seems more plausible. I don't think the 4.3 could swing a 21* at 4800.

That...and the other number (1.7) worked sooooooooo well.

[mattyboy]

Sean
yes 1.68 is almost 1.7 my 240 hp v8 just about gets a 21 to 4700 on a 1.61

he could do simple mods 4 bbl carb maybe an intake and get another 25-35 hp out of it and go up a pitch or two

if he can add the hp and get a 23 with 10% to 4700 he is around 55mph

[DONZI-DON]

I just picked up a 1994 SWEET 16 last week. Had it out tonight for the first time. She ran 58mph at 5000rpm in a foot of choppy water. Has a 23 pitch stainless prop and if I would of played with the trim Im sure I could have got it at 60mph. Trim was 100% down forcing the noise to cut through the chop. I was pretty impressed with how well this boat cut through the water compared to my last one!

Just bought a 90 Sweet 16. It was a two owner boat and very well maintained. Replaced the original fuel pump with an electronic unit as the original was failing. Being my first Donzi I was wondering what this boat should do top end. I have only been able to hit 47.5 gps. Granted that was in a bit of chop 1 1/2 ft waves but I would think this boat would have a little more top end. It only has the 4.3 but still, trimmed out to the max I'm surprised it isn't a 50 - 55 mph boat. Any advice? Oh and BTW I'm running a 14 1/4 21p viper stainless prop. I've included some pics of the boat just for fun. (Picked it up for 5600 so I'm not complaining just wish it had a bit more top end.

[danz]

I just picked up a 1994 SWEET 16 last week. Had it out tonight for the first time. She ran 58mph at 5000rpm in a foot of choppy water. Has a 23 pitch stainless prop and if I would of played with the trim Im sure I could have got it at 60mph. Trim was 100% down forcing the noise to cut through the chop. I was pretty impressed with how well this boat cut through the water compared to my last one!

does your boat have the 4.3 or a v8 ?

[chaduski]

Thanks for all the input so far! I do LOVE the way this boat rides. With the trim tabs I'm taking big waves better than my friends 23 -25foot boats. I am torn as to what to do. I paid the right money for the boat so I could do a small block and alpha one swap but there is something fun about sneaking around with old OMC outdated stuff and still hitting the 60mph mark. Maybe this winter a 4.3 build is in the cards. Is it reasonable to be able to approach 275 - 300 hp from a 4.3? If so what kind of things are going to shatter in my OMC drive?

[DONZI-DON]

does your boat have the 4.3 or a v8 ?

Has the 4.3LX with a Quick Silver 23 pitch prop - A friend of mine owns "HOT TO GO RACING", He runs/organizes a lot of the Poker Runs on the East Cost. You Tube his boat (HOT TO GO RACING BOAT), 175=MPH.........sick!!!!

http://www.youtube.com/watch?v=6wZgd8Zpp3c


As of today I have only had it out 5 times since I bought it a few weeks ago. Rob (Hot to Go) has the boat now. We are installing Thru-Hull Exhaust this week. The last time I had it out again I had my Dad and my son with me (about 500lbs) and I played with the trim tabs. I got it to 59mph but at about 5200-5300rpm's. Not real comfortable running a stock V6 at those rpm's. I don't plan on pulling skiers or tubes with this boat so after the exhaust gets done I'm gonna try a 25 pitch prop to try and get the r's down............... Rob is already coming up with a MILD V8 build for me when this V6 is tired.

FYI - Rob, HOT TO GO RACING 716-418-6131, Grand Island New York / Mention my name if you call him.

[John C in PA]

Just bought a 90 Sweet 16. It was a two owner boat and very well maintained. Replaced the original fuel pump with an electronic unit as the original was failing. Being my first Donzi I was wondering what this boat should do top end. I have only been able to hit 47.5 gps. Granted that was in a bit of chop 1 1/2 ft waves but I would think this boat would have a little more top end. It only has the 4.3 but still, trimmed out to the max I'm surprised it isn't a 50 - 55 mph boat. Any advice? Oh and BTW I'm running a 14 1/4 21p viper stainless prop. I've included some pics of the boat just for fun. (Picked it up for 5600 so I'm not complaining just wish it had a bit more top end.

Nice lookin' boat!!! I have a 1992 Sweet 16 with a Ford 302 HO, 2 barrel carb, 200 HP. Stone stock except for thru hulls and K&N air filter. The boat came with a 23" Viper prop which got me to (I think) around 56 MPH (GPS)at 4400 RPM using a 1.58 Cobra drive. I replaced the Viper prop (too much chine walk) with an OMC 21" SST tuned by DAH Props. I regularly run (no passengers, 1/2 tank of gas) 59.8 MPH (GPS) at 4800 RPM. FWIW: the air filter gave me about 0.5 MPH.

Feel free to PM me if you have any questions.

John C

785f6b1a-22ac-4d9a-95bb-ec77ebcc8fe8[1].jpg

[cgentile]

I run a 13.75 lazer 11 25 pitch, 4.3 4 barrel, 1.84 drive.. Down wind 6-10 chop runs 57mph GPS on the edge. half tank of fuel and 400 pounds of two riders. one guy to hold the gps.
My boat has always been quick but you have to really release it to get it loose to go fast ..
no tabs set fully up.

Right around 5100 rpm .. im sure it will let go at some point... but so far its pretty solid...

[DONZI-DON]

I run a 13.75 lazer 11 25 pitch, 4.3 4 barrel, 1.84 drive.. Down wind 6-10 chop runs 57mph GPS on the edge. half tank of fuel and 400 pounds of two riders. one guy to hold the gps.
My boat has always been quick but you have to really release it to get it loose to go fast ..
no tabs set fully up.

Right around 5100 rpm .. im sure it will let go at some point... but so far its pretty solid...

Are numbers are almost dead on. I have noticed boat is faster with about a 1' chop................

[woobs]

I run a 13.75 lazer 11 25 pitch, 4.3 4 barrel, 1.84 drive.. Down wind 6-10 chop runs 57mph GPS on the edge. half tank of fuel and 400 pounds of two riders. one guy to hold the gps.
My boat has always been quick but you have to really release it to get it loose to go fast ..
no tabs set fully up.

Right around 5100 rpm .. im sure it will let go at some point... but so far its pretty solid...

Here's the paper version with 10% slip.... make that 12 % and you're right on the money at 57.7mph.

25	x	5,100	=	127,500.00	=	65.6		0.9		59.1
1.84	x	1,056	1,943.04

[cgentile]

Okay if those numbers are good which I know they are , what happens to my boat with a 5.0 mpi a 1.49 gearing and the same prop.... ?????? that would be the next power plant when the votex lets go. god forbid not this year ...
And when i say on the edge , and loose its just rocking side to side every so but nice...
CG

Here's the paper version with 10% slip.... make that 12 % and you're right on the money at 57.7mph.

25	x	5,100	=	127,500.00	=	65.6		0.9		59.1
1.84	x	1,056	1,943.04

[woobs]

Okay if those numbers are good which I know they are , what happens to my boat with a 5.0 mpi a 1.49 gearing and the same prop.... ?????? that would be the next power plant when the votex lets go. god forbid not this year ...
And when i say on the edge , and loose its just rocking side to side every so but nice...
CG

What RPM will the 5.0 rev to?

Assuming the same 5,100 and 10% slip...

25	x	5,100	=	127,500.00	=	81.0		0.9		72.9
1.49	x	1,056	1,573.44

[cgentile]

Mercury spec sheet says a 5.0 260 horse mpi is 4600-5000
I would think the fiberglass would start to melt on re entry at 72. or the driver and guest may freak..lol

What RPM will the 5.0 rev to?

Assuming the same 5,100 and 10% slip...

25	x	5,100	=	127,500.00	=	81.0		0.9		72.9
1.49	x	1,056	1,573.44