Performance matrix

[Terry Jackson]

Could some of you experts create a performance matrix, such as the example below, to help us amatuers decide what mods to make? And help point out cost vs gain? Is this info available anywhere?

Mod Gain % low % mid % top Cost
B reeds 20% 10%` 2% `$200
Tuner -10% 0% 5% $400
SVS 0% 2% 5% $1800
Comp 5% 5% 5% $150
125 to 145

[Techno]

Remove pitot tube and install GPS
$100 for hand held 200-400 for dash mount.
Increase 2-3 mph over a hundred mph.
Also shows accurate speed rather than the wishometer.

A lot of the things depend on the hull and motor so there is slight problem with generic list.
Hp increase will show a speed increase but forgot what it was, it's a pretty big increase for a small speed increase.

[WATERWINGS]

Where can I get a gps speed-o for $200, I might be able to swing that.


JOHN MASON

[vector mike]

The ones I have seen are $200 for the dash mounted speedo and $200 for the receiver. $400 vs. $100 for hand held one. I know which one I am getting. :)

[WATERWINGS]

If your paycheck is like mine, we will be getting the $100 GPS!

JOHN MASON

[vector mike]

Boaters World has the Etrex GPS for $105. And it comes in a cool yellow too. :)

[WATERWINGS]

DOES THE ETREX HOLD MAX SPEED?

Saw in another post (not sure of the brand, but the number was a 310) at wally world for $75

[vector mike]

They have a couple of different models but the one I'm getting is yellow and it does have a max speed recall.

[WATERWINGS]

I was thinking that Wallmart said the yellow ones were discontinued,(the Etrex?) I need to also check into the 310

[VectorPat]

I found mine on sale at Sports Authority for $99 this past summer..Its also nice to be able to follow the plotter on it when your running back up river..The only thing I found is the batteries need to be strapped in tighter or they will shake loose..

[vector mike]

I was there last week and they still have them.

[WATERWINGS]

I don't think we have one of those around here.

[vector mike]

You can buy it online. Here's the link.


BOATERS WORLD (http://govinda.nu/sports/boating/boaters-world/)

[WATERWINGS]

THANKS!

p.s. I have an '83 vector, wish I had a bridgeport...91.6 GPS will have to do for now. What do you get out of yor B.P.?

[vector mike]

I just looked on their website and they say they are $114. They were on sale last week. Hopefully they are still on sale. :)

[Techno]

The displays are a bit tiny but do the recall thing. Average speed, time and distance too.
There is a wire you can get that will supply battery power, I'm pretty sure.
Also make sure it can't go over the side. Use the wrist strap to make sure since they aren't water proof, don't float.
Mine went over but I did find it. Had to take it apart and dry it out.

I thought there was a dash mount complete that was $200 but guess I'm wrong. The higher end hand helds could be dash mounted and supply a super size readout + the navigation. Thats the route I'm eventually going.
About this 100
To this 100
Might be bigger.

[WATERWINGS]

How fast does that Vector run with that Bridgeport?

[Liqui-Fly]

Holds max speed also. 140 something mount and cord were another 60 or so. Very happy with unit.

Note max speed is not mine.

David

[WATERWINGS]

Does that river flow 3.6 MPH?

[vector mike]

I don't have it together yet. I just got the Bridgeport and I'm still building the Vector. I have my Viper running with the modified 200 on it but don't have a GPS yet. I getting ready to tear it all apart and start building the BP motor. I'm hoping for mid 90's with the BP and the Vector. :)

[Nosubforcid]

The return of the 22hp water pump. NO WAY IN HELL DOES REMOVING A NORMAL PITOT TUBE REDUCE TOTAL DRAG ENOUGH TO ADD 2-3 MPH at 100 mph unless the boat in question is 40" long with an OPS .90 for power. Has anybody considered how small the total drag calculations on the hull and gearcase would have to be for the pitot to have that kind of effect. How does this ridiculous stuff get started?? We need a new High Performance Boating Legends section here at S&F.

[mxz]

Waterwings,
91.5mph in your Vector! Thats great if its a stock fishin motor. What kind of setup do you have? Motor size, prop, etc.
My 81 Vector gets 84-85mph with a bone stock 81 225 Merc with CLE gearcase. Would love to hit 90! Maybe this summer I will bolt my bro's 2.4Bridgeport on the back of the Vector and see what it does.

[Techno]

Nosubforcid I don't kow how it gets started but it's easy enough to check. Run with it down and with it up! Maybe someone has done it and that was the result.
You lost me on the total drag thing. How much Horsies does it take to go from 100 to 103? How much drag is a normal skeg worth?

Not slamming you. I agree on the lets see whats true thing. I prefer someone doing something and showing the results more than 50 people saying something is so, without ever checking themselves.

[Instigator]

have heard all the theories but never talked to any one who's done it.

[Hydroballistic]

Techno,

On the subject of how much HP to add 3mph...........
At a Mercury Dealer meeting several years ago there was an engineer that was doing a presentation on performace of there "drives" (lower units). I do not remember a whole lot that he said but one thing that sticks in my mind was.......
With a boat that is propped out, set up, and running to the best of it's potential, on AVERAGE (this may have had the I/O's figured into this too) it took 15HP to increase a boats speed by 1 MPH. Different hulls may take more or less, but that was an average.

I don't think that it will take that much on the lighter hulls that most of us run, but it is something that will make you scratch your head.

Gregg

[vector mike]

That seems a little high to gain 1 mph. Like you said though, maybe that is for the I/O boats. I would think that if you went from 200 to 260 you would gain more than 4 mph. :)

[Wile E. Coyote]

Hydro is close to correct with his numbers, that is for an optimally set up I/O. Those are the approximate numbers my buddy used for his Magnum and it worked out pretty close. It is most likely different for an outboard (god I hope so :p )

[vector mike]

I would hate to have to go from a 150 to a 300 to gain 10 mph. :eek:

[Instigator]

10 HP's = 1 MPH

Seems to be fairly close on a light, good running O/B

[Mark75H]

Nosub is correct again!

If your pitot tube was causing that much drag it would also cause a noticable steering change with it up or down.

There is one here among us with numbers and formulae for drag calculations for stuff like this . . .

Jimboat!

Buy his book or software and you can check all kinds of stuff like this!

Nosub this is one of the big time race boat myths, I hear it repeated a dozen times every year at outboard races; there is no way we can kill it altogether, but a good article here on SnF and in a print mag might go a long way.

A one way pass one time is not a scientific test.

[MODIFIEDOUTBOARD]

To really do the calculation correctly you would have to know a whole lot about the rig such as:
Drag coefficients of the hull from the water which will change.
Drag coefficients of the hull from the air which will change.
Drag coefficient of the drive system which will change.
Prop efficientcy which will defenitely change.(Progressive pitch race prop? "Forget about it")

*Which will change- varies as the boat goes faster or slower or changes in attitude of boat or hull lifts out of the water.

If one had the differential equations to describe the above then a mathamatical model could be made to accurately predict speed.

Since no one wants to pay for $200/hr research let alone a $60/hr shop rate for things that have to be done lets look at
plan B.

I came up with simple algerbaric formula that works for a limited number of applications.

It assumes that increase in speed is proportinal to square root of the hp.

Speed = k x (hp)^.5 , k = (speed) / (hp)^.5

Example Carolina Skiff 14' went 18mph with a 15hp enine.

k= 18/ (15)^.5 = 4.64

How fast will it go with 30hp?

Speed = 4.64 x (30)^.5 = 25.5mph
it actually went 27mph with the 30.

Question: Why can't prospective High performance boaters come up with a budget Matrix that shows how much of a budget they have for engine work?

[Liqui-Fly]

Same prop and basically smaer set up and gearcase. Went from 68 mph to 80. Impoissible question to answer if you ask me. Depends on what speed your boat runs best. There's lots of humps and valleys in hulls and in motors. Could you come up with something for a particular hull....maybe. With an onboard dyno and gps hehe. Actually when I went over 80 when I came back in my pitot was up. Maybe I picked up an extra 2 or 3 from it. Wish I'd know that sooner:D

David

[WATERWINGS]

When I ran 91.6 I was running a borrowed 30 pitch inline chopper even with the pad, turned it 6700. I normally run a 26 trophy with heavy cup, (I know, not a performance prop, everybody tells me thats the wrong prop for that boat) it runs 88.3 about 3/4 below the pad, (sounds like pretty good performance to me)

Its a 2.4 200, ported, hogged exhaust chest, relieved mid, tight heads (160-165 psi) (I know too much comperssion, but so far so good)(except one gaulded piston) two holed CLE, 6" setback.

[Instigator]

If you change your gear case you might get your 90 MPH's you're after??
I am just finishing up a Vector project and have been studying them for the last two years.
A stock coned gear case is supposed to be faster than anything else on a pad vee bottom.
I think I've read that the CLE (the prettiest) is the least efficient.
From what I understand, the CLE's and Sport Masters are for tunnel boats only!
Borrow one and try it, you might be shocked.
Also, try some Cleavers if you can get your hands on a few.
The round ears are supposed to be fastest on the Viking/V-Kings and Cleavers on the Vectors.
Unfortunately, don't yet know this from experience but have read and been told all of this multiple times from people I trust.
Gary

[Nosubforcid]

Modified it doesn't have to be that complicated, you can readily determine the drag of most any pitot then solve simultaneous equations for total drag assuming a 2-3 mph gain from removing the pitots drag. The total drag numbers will be impossibly low. Try it and see for yourself.

[mxz]

Instigator,
Your right I do need to try a stock unit that has been coned, hopefully in the spring. As for cleavers I have actually heard the opposite from a few people good for Vkings, bad for Vectors, funny huh. I have tried a couple of cleavers both with unsatifactory results. My Vector was very hard to drive and felt like the ass end was trying to come around. Bad steering torque too. My fave prop on the Vector is my Mazco RE4 28" Great handling and acceleration, top speed around 80. I see around 85 with a 30" small blade chopper but it sure doesn't handle like the Mazco. The SRX's have worked pretty good on my Vector also.
As we know nothing better than trying everything you can in the quest for more speed.
Would love to know how your Vector runs when you are done.
Brent