Approx. MPH ?????

[sinfuse]

i have a 210 baja sport w/ 260 merc. and alpha I outdrive ..... what type of mph should i get at optimal run conditions???? what can i do to squeeze a few more mph??? the boat is stated to weigh 2480 lbs

 

[JB]

Re: Approx. MPH ?????

Hi, Sinfuse.<br /><br />Well, I made some assumptions about the deadrise in your hull and true weight and came up with about 60mph.<br /><br />That assumes ideal prop and trim, nearly flat bottom at the stern, and an on-the-water weight of about 2800lb.<br /><br />Good luck.

 

[sinfuse]

Re: Approx. MPH ?????

thanks for the info !!! i guess i will be happy with 60mph "FOR NOW" haha!! i cant wait to get it in the water !!

 

[mattttt25]

Re: Approx. MPH ?????

my bud has a stingray 220ds (deck boat) with the same engine. i think the running weight is about 4000lbs with fuel and passengers. he tops out at almost 50 mph in ideal conditions. 60 sounds about right for you, but you can ask at www.cbpba.com. the guys that frequent the site drive nothing but go-fasts. good luck.

 

[SS182]

Re: Approx. MPH ?????

JB,<br /><br />Please post the formula that you are using! I am happy to have you do the math as well... if you want!<br /><br />Thanks,<br />SS182

 

[JB]

Re: Approx. MPH ?????

Sure, SS182.<br /><br />Bottom factor is 150 for a deep vee, 175 for a semi vee and 200 for flat. That is the shape of the bottom at the stern, not the bow.<br /><br />Theoretical top speed assumes ideal prop and trim.<br /><br />Top speed = (the square root of HP/weight)X bottom factor.<br /><br />For Sinfuses boat I used 2800lb for weight and 200 for bottom factor.<br /><br />260HP/2800lb = .093<br />Sq rt = .305<br />X200 = 60.94mph

 

[P.V.]

Re: Approx. MPH ?????

My guess, ..... 52, 53 mph, maybe 54 with an aluminum prop. Probably a 21" or maybe a 23". With a Stainless prop add 2. maybe 3 mph... due to higher bow lift. That's with a 2 barrell. 4 barrell, add maybe....hummmmm...3 or 4 maybe... That puts it at high 50's or low 60's. BTW, 2480 lbs is real light for a 21' hull.?????

 

[golfer]

Re: Approx. MPH ?????

JB....<br />That math isn't working for me...I have a 27' Fountain Fever with a HP500 (470 HP) Merc...Even using the dry weight of the boat at #4800, the 470 horsepower, and a flat bottom 200, I come up with 62.58 MPH. Boat GPS is 75 MPH. Realistically, weight on the water is #5500 with a 175 hull multiplier, would equal 51.15 MPH, creating an error in the estimate of 31.8%...Did I do something wrong in the equation?

 

[janichol]

Re: Approx. MPH ?????

Wow, worked for me.... 22' Aquasport, 200 hp Johnson, semi V came out to 43.75 mph. My GPS top speed last time out (when it was running right!) was 45 @5600 rpm. And I thought it was underproped!<br />Thanks JB