How Much Faster Would I Go?

[scalywag]

My fishing cat does 45mph (GPS) with a pair of 225 3liter(carb)Mariners....
If I go to twin 300 promax's, how much speed increase
should I expect? I have a them mounted on 10" Jackplates.......
The hull is 36'X12'..... If I dont see atleast 10mph gain, It wont be
worth the investment...
http://img244.imageshack.us/img244/2527/36twinvee028smallyu6.jpg
http://img132.imageshack.us/img132/7207/twinvee027smallqd3.jpg

[Frank Molé]

thats a tuff one scaly:confused: see ya weds night...:D

[scalywag]

You can say that again Frank!

[scalywag]

You can say that again Frank !

[Frank Molé]

yes i could:eek:

[scalywag]

Maybe somebody can loan me a pair?:rolleyes: :rolleyes: :rolleyes: :confused:
Just to try out?

[Jay R.]

prop calc should give you an idea, I had one that you plug in all you numbers, and its would estamate new numbers on what you change.

[baja200merk]

put ur moters on there;)

kevin:D

[transomstand]

My prop calc says 52 mph going from 450hp to 600.

Pete

[Jay R.]

whcih one ya got and where did you get it?

[scalywag]

Thank's Pete....about 7mph gain...Just what I predicted about 10mph or less.
Not sure its worth the extra 10G investment?
Then again....50+mph is respectfull for a big barge like that!!!!:eek:
........So 60s is outta the question I guess?:p :p :p With twins.

[The Big Al]

You can probably get 3 to 5 mph now changing those dump truck props.


Yes, the 300 Pro max will give you more than 10 mph. Gain.

Better props, and the better lower unit's on the 300 would get you 5 mph before you even apply the extra power

[transomstand]

whcih one ya got and where did you get it?

I have the one from the Hydrostream Registry, it predicted the speed increase on my Ventura within a tenth of a mph, going from an XR2 to a 200.

Pete

[The Big Al]

You have to calulate the RPM differance between the 2 engines also.

5500 to 6400 rpm is a lot more than 10 mph!

[Jay R.]

thats what i had, but the link no longer works. anyway you can Email me the file?

[scalywag]

You have to calulate the RPM differance between the 2 engines also.

5500 to 6400 rpm is a lot more than 10 mph!

I hope your right Big Al.:confused:
If I can get close to 60.... I will cream my pants with joy!

[The Big Al]

I have the one from the Hydrostream Registry, it predicted the speed increase on my Ventura within a tenth of a mph, going from an XR2 to a 200.

Pete

Also figure the promax engine are in the HP group, they are more of 330hp.
Also they are brutes. And have better lower unit's.
They are top end performance engines.

Example would be his current engine on a 21ft Bassboat would be a 55-65 mph boat, same boat with the 300x 90mph plus!

[scalywag]

Your right...Im gonna try a prop change first...I have a pair of
Hydomotives layin' around.... The Garbage truck props that are on
the boat now, give me perfect RPMs at 5800....Plus they plane off
the boat instantly..... I would sacrifice that for a few MPHs/...:rolleyes:

[The Big Al]

EXPECTED SPEEDSFew people have as much seat time in more types of Bullets with different types of motors and setups than Paul Nichols. Below is his response to the most asked question of and by bullet owners..... 'how fast' ?
On behalf of everyone... Thank you Paul..
=============================================================

21'ers - 225 PM/ S-master 76 MPH (T-master 78 MPH)
'' -225 X 80 MPH
'' -225 EFI 78 MPH
'' -250 XB 81 MPH
'' -280 Sport 87 MPH
'' -300 PM 89 MPH
'' -300 X 92 MPH


Also consider the gain of the Performance lower unit, in the 2 performance lower's listed they were 2 mph apart.
The stock lowers that your 225's have no speed enhancement.
The bullet with stock 225 engine are in the 70mph range.

[scalywag]

So whats your guess Al?
Looks like I will be swapping my 225s for 300s...
You never know...The hull might rise and jump onto
the lowest chime, with all the extra air in the tunnel...
Less wetted surface = more speed....
YOU GOT ME ALL EXCITED NOW>>>

[The Big Al]

Humm, you driven, me watching!:eek:

You live threw the first, then I'm on for the second!!!:D

HA HA!!! :)


That thing would be bad!

People would swear it's a undercover boat!!!!!!

[scalywag]

You wanna laugh??? Me & Lightspeed were gonna rig it with a
pair of 496s and Bravo's....Offcourse we would have to cut down
into the sponsons, Glass in some new stringers, and box it out....
...................Heres one with 320 Yanmar Deisels...............Bravos
http://img138.imageshack.us/img138/6859/floridafeb06037smallyj2.jpg

[The Big Al]

Things we laugh at, we mostly end up doing. Are someone else will!

You got to remember what this board is about!

I would do it and run the exhaust out the side of the boat! 1 pair on each side.

See, already planing!!!:eek:

[1BadAction]

put 2 300XS's on it :D

[scalywag]

Here's an exhaust pic for ya?
http://img242.imageshack.us/img242/6057/floridafeb06024smallib8.jpg

[scalywag]

put 2 300XS's on it :D

GOTTA BE GOOD ON GAS?
That is the perfect senario.....300XSs
Not sure I wanna drop 40 large!!!!:eek:

[lightspeed]

Just Leave The FN Thing Alone ///////// You Dont Have The Bread To Put New Motors On It ///Where You Going Anyway :mad: :mad: Your Not Going Out 50 Miles Offshore Fishin ???????Are You?????? Those 225s Run Like Two Fine Swiss watches :eek: :eek: Leave Em :rolleyes: :rolleyes: :rolleyes: :rolleyes:

[tux974]

Scaly, Bash has 1-300X and I have the other. Something to think about;) :D. Tony

[Monkstr6]

I ain't going to lie. It makes me really wonder were some people get that much EXTRA cash that they want to go and buy TWO new motors just to go Maybe 10mph faster? I guess if you have it you may as well use it but it seems more and more that me with my 1973 boat with a 1975 motor, just don't fit in with most of these guys on the board now. It is for fishing right? My fishing boat has a 40hp tiller on it and I am very happy with it. Good luck either way but unless you found two motors for just a steal of a deal I would just try some different rigging setups. I am sure the optimal setup would get you a few more MPH. Zach "junkyard Boater"

[Juggernaut]

if you want to go fast, buy a STV, if you want to go fishing, stick with what you have

[Dave S]

The middle.:D See Tripps.;) Or buy a Crackmate for funn......:rolleyes: