CayFomula

I have an 89 Formula 272SR1 I am thinking of installing a pad in my quest for more speed. Has anyone here tried adding one to and older V-bottom?

Ian

resurrected

Good question! I can't help.....sorry! But have wondered the same thing myself. I always chalked it up as too much work for the potential gains, and potential problems, like making the boat unstable at speed. For the time and money I am blueprinting the hull I have, and throwing money at the engines! I am interested to hear what guys that know what they are doing have to say, because I don't have a clue!

CayFomula

Thanks for the responses guys.

The bottom is straight except for the standard Formula turn down between the outer strake and chine. I doubt that this has any effect at high speed as I don't think it is in the water. I have sharpened the edges at the transom however I do need to sharpen the strakes better.

I have done a bit of fiberglass work however there is guy here who has done quite a lot over the years that I would turn to for assistance.

I’ve already put money into the engines, drives and props, gone 62 mph when I bought it to 93-94 mph currently (all GPS). I am looking for ways to increase efficiency of the hull now.

Ian

martiniboat

Ian, that's a serious speed increase

You didn't mention tabs but you have mentioned hull 'efficiency'. Since tab are essentially an extension of the hull have you tried a longer tab on your rig? (this is assuming you have tabs of course)

Many of my customers, in there quest for speed:

A) Add a pair to gain more control in the speed range you've mentioned

or


B) Swap out existing plates for a longer one. This will allow the much desired hull control without having to deploy the tab as much = less drag, more speed

Are you heading for the century mark? You're damn close


Brian

P.S.- I'd be surprised if no one has addressed your original question

Zanie

Looking at the pad on my 1984 Excalibur, the pad is not so much added as it is cut in. I don't think you really add a pad as much as cutting off the bottom of the V, right?

You kinda need to drag your boat around on the blacktop without the trailor until the desire pad is obtained.............then smooth and paint.

But seriously, I don't think the dollars spent per MPH gained vs the risks of ill handling are worth it. just my .02

By the way, those are some mighty impressive speed numbers!!!
DS

glassdave

iTrader: (1)

have you thought about putting boxes on it?

CayFomula

Brian,

I have tabs (relatively short) but I try very hard to avoid the need to use them. I rather balance the load so it doesn't scrub any speed, as a matter of fact when I am running hard they are all the way up.

GlassDave,

I have but the engine compartment is so tight in this boat (if I drop a quarter it will take it a couple of runs int he ocean to get to the bottom) that I will have to do a lot of mods to raise the engines. I went with the IMCO 2" shorties instead.

Thanks for your input guys.

Ian

LFarr

CayFormula

Impressive numbers !!

I'd be interested to know what you're running for engines, gears & props.

I have a similar boat 27.5 ' searay single engine that I've taken from 43mph with origional 454 to 75mph/gps with IMCO 2 & 3" shorties 4 & 5 balde props, and procharged 502.

Someone mentioned boxes, there are a couple of products out there that can move your drive back....my experience this gave me close to +10% increase in top speed.....this was when I was in my other wise stock configuration and the top speed went from 48 to 53 mph.

I have made some bottom mods that moved me from 61 mph to 67 mph.......too much to write about here.

If you want to swap stories.....I'm at 916-797-2228

32storm

Have you tried to lighten the boat? Formula used a lot of wood in that boat. Great built, and riding boat... but one heavy SOB. May not prove for dramatic gain at speed your running now. But, every little bit helps.

CayFomula

For motors I am running 454 mag Bravos which I rebuilt and added ARP rod bolts, Dart Pro1 CNCd heads, a Crane custom grind cam and Whipple superchargers with intercoolers. I have never dynoed the motors but based on performance of the same hull with motors dynoed at 638 hp I am guessing I am making upward of 725 hp which is higher than I initially estimated.

For drives and props I am running stock Bravo XR uppers with IMCO 2" shorter lowers with 30"p Bravo 1's labbed by York. The gear ratio is 1.5 to 1.

I haven't tried boxes on it but I picked up 4mph with the shorty lowers.

LFarr,

Did you see additional gains with the shorty lowers after adding the boxes and are the boxes neutral or 3" lift?

32Storm,

The speeds I mentioned were actually run with a full tank (135gal) of fuel, a full cabin including refrigerator and two people. I haven't done much to lighten the boat, only the aluminum heads and stainless marine exhaust however these are probably negated by the additional weight of the intercooled Whipple. I have just recently replaced the stringers and bulkhead in the engine compartment and I used Nidacore for the bulkhead however I did go back with wood for the stringers.