Speeds for pre Fastech Formulas
 

I am looking at going up in size, but not up in costs. Love the looks and ride of the older Formulas, early to mid '90's vintage (pre Fastech, pre molded in swim platform), but I am curious what kind of speeds these boats ran.

Ideally I want to run right at or slightly above 70 top speed, I do not need to be the fastest guy out there, but I just want to stay in the middle of the pack.

How much power would a 357 SR1 need to run 70+? Would 454 mags or 502 mags do it?

How about for a 31 footer of that vintage?

Re: Speeds for pre Fastech Formulas
 

It will be easier, and less expensive, to get a 311 SR1 to run 70 plus than a 357 SR1.

The 311 is MUCH more boat than a 303. When Formula started "molding" their swim/silent thunder platforms in place, they, like everyone else, included that in the LOA. Ergo, the 311 SR1 became the 336 SR1. A 303 with a molded platform is your basic 27/28 footer with a molded platform. If you compared side by side a 311 SR1 with no, or a bolt on platform and a 303 with the molded platform you would not believe your eyes. I personally would take a 311 over a 303 without thinking about it.
Unless you only run on lakes (not meaning the Great Lakes here guys).

A 311 with 502's should put you over 70. The same motors in a 357 you will run probably 64/65 or thereabouts.

With a light load I can kiss 70/71 with my 89 311 with 454's running Hydromotive Quad IV props. I picked up 3 mph at WOT with the Quad IV's over the Mirage the boat came with. This is with your basic 445/365 horse motors. I'm swapping exhaust from the stock Merc to EMI Thunder units, aluminum. Losing 130 lbs of weight and should pick up a couple of ponies. If I can pick up 2 mph I'd be happy. I am also taking the silent thunder system off and installing new 6 inch (exterior) thru hulls rather than keep the extremely short existing tips. Between the exhaust swap and dumping the box I've been told I might see a total of 4/5 mph gain. That'd be cool. I'll believe it when I see the proof on the GPS. If I only gain 2 total I'd still be happy cause I don't like the silent thunder.

I would guess it would take at least 500 if not 525 per side to get a 357 to 70. They are, as all those model Formulas, heavy boats. But in the rough you can't beat them.

I'd guess that it would take a 357 close to a hundred more horsepower per side to run with a 311 at the same speed. But I'm only guessing here. Other members I'm sure will chime in here with more experience with a 357.

Re: Speeds for pre Fastech Formulas
 

My boat is an 86 302 SRI. I was rafted up to a 353 a while back, and the 353 isn't more than two feet bigger than the 302. The problem with the older Formulas is most were equiped with TRS drives. To get the speed you are looking for, you'd be tearing up the TRS. Some of the Formulas came with Kaama drives, which can handle the power needed better than the TRS. The Kaama's are also faster because they have less drag than a conventional outdrive. The previous owner of my boat said it would do 78.6 on the gps. I haven't run it that hard, but I have no reason to doubt him. It came with 454/420's.

Re: Speeds for pre Fastech Formulas
 

My 357 454's kammas 450hp 67mph. Some chop will really help the 357. Not a flat water boat.

Re: Speeds for pre Fastech Formulas
 

Cuda, I've always heard that the TRS drive would actually handle more power than the Bravo One, the drawback was that the seperate transmission moved the motors forward which cut down cockpit room and that the hydrodynamics were poor. I know of a couple of older Cigs that are running TRS with 650 hp and they have not had any problems, but both owners have said that if they were running Bravos they felt they'd see another 4 maybe 5 mph on the top.

I love those surface drives because of that totally cool rooster tail. Rumor has it they are not the best in docking manuvers. There's this story going around up at the Holiday Inn by the airport.........................................

Then again when one's boat is "trailer bound" one does not have any of those concerns.

Re: Speeds for pre Fastech Formulas
 

My '87 311 is running around 80 mph w/ TRS w/o problems. Not that it is kept at that speed for very long though. The power package has been this way for over 10 yrs.

Re: Speeds for pre Fastech Formulas
 

Jaybird

What Power are you running?

Re: Speeds for pre Fastech Formulas
 

Thanks for the replies guys, I am just starting to look around, but this one caught my eye (at least from a distance). Do not know how much or have not talked to the dealership or taken a ride. Just love those long lines and long bow.

But judging by what you are saying, mid 60's is what I should expect as a top end speed.

http://www.kentuckianayacht.com/cgi-...w.pl?index=579

Re: Speeds for pre Fastech Formulas
 

454/420's with B&M 174's.

Re: Speeds for pre Fastech Formulas
 

My friend had a 357 w/ 502's pushing around 500 hp in it. That boat went around 70 mph. Mid 60's is probably a fair estimate for one with 420's.