Mods for my low performance (310 hp) 454
#21
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Location: Wichita, KS
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Re: Mods for my low performance (310 hp) 454
Mike,
These sites can help you pick a prop for what you have and can help plan how much prop and power are needed to meet your speed goals.
speed/power calculator - click here
prop slip calculator - click here
Here's a link to some thoughts I have on your engine - my plan
Finally, here's a great link for BBC head flows - head flows
These sites can help you pick a prop for what you have and can help plan how much prop and power are needed to meet your speed goals.
speed/power calculator - click here
prop slip calculator - click here
Here's a link to some thoughts I have on your engine - my plan
Finally, here's a great link for BBC head flows - head flows
#22
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Join Date: Dec 2000
Location: Beautiful Lake St. Clair,MI
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Re: Mods for my low performance (310 hp) 454
A 25 Mirage Plus sounds about right for that boat. However you have to see what RPM the boat is running at full throttle to see if it is in the ball park. Remember, there is no free lunch, if you go to a 23 your hole shot will be better, but your cruise speed will suffer. Lab finishing may help, but you need to talk to one of the prop shops on the board here and tell them what you want to do. Labbed props are not as resistant to damage because they are thinned. Keep that in mind.
#23
Re: Mods for my low performance (310 hp) 454
Well, the prop I have is in need of some repair. The blades are rough and there is a slight wave in 2 of the blades. The holeshot imho is embarassing.. anything that takes over 10 seconds to get off plane is bad I think.. its taking me about 20+ seconds to get off plane with 4 medium sized people in the boat and 1/2 tank of fuel. I like the speed of the boat now but it would be nice to accelerate at a decent rate out of the hole.
#24
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Re: Mods for my low performance (310 hp) 454
Originally Posted by Unitek
Anyone know what prop this boat should have on it ? It has a 25p Mirage Plus and its a pooch outta the hole. takes about 30 seconds to get off of plane once it gets on. Im thinking it might need a 22p or a 23p Mirage or just about another 150 hp . Would lab finishing do anything to the 25p speed and torque wise ?
Mike
Mike
Is the prop blowing out or is the motor lugging?
What max rpm is she getting?
You may want to consider a 24p Bravo I 4 blade...
The 4 blade will give you better hole shot and better cruising, but you will loose 1-2mph on top...
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Patrick
Patrick
#25
Re: Mods for my low performance (310 hp) 454
It was pulling about 4400 to 4500 rpm . It felt like there was more left ( I know it only revs to 4600 stock ) in it . I live on a medium sized lake and total top end right now isnt a concern . I would like to get something with great holeshot and decent top end for where im at and then get the 25p mirage plus lab finished for lake michigan top end runs . I will look into that Bravo 4 blade 24p.
Mike
Mike
#26
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Re: Mods for my low performance (310 hp) 454
Originally Posted by Unitek
It was pulling about 4400 to 4500 rpm . It felt like there was more left ( I know it only revs to 4600 stock ) in it .
I ran a 25p Mirage plus for top end speed at about 4500. And a 26p Bravo for rough water handling.
My engine would not turn a 24p Bravo more than 4600 and turned the 26p at 4300-4400.
If you carry a load the 24p Bravo will be a great prop. Light, you may be able to spin a 26p.
From what I found and have read the 26p Bravo measures light on pitch and a 25p Mirage + heavy.
It's all a trail and error game...
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Patrick
Patrick
#28
Re: Mods for my low performance (310 hp) 454
I have the same boat and looks like the same power 7.4 300h.p. My best top end so far is with a 25 Mirage plus. But its a dog out of the hole. Tried plain 23 Mirage, not good. Then 22 bravo,great out of the hole and ski's well and the boat works much better,but not enough pitch 57.8@4950. Next was a labbed 24 Bravo,works as well as the 22,but still need more pitch 62.8@4800. I was thinking of trying a Hydromotive. Maybe a 26 Bravo. I don't have much room between the sunpad and the flame arrester for higher intakes. That big block is stuffed in there. Doug
#29
Re: Mods for my low performance (310 hp) 454
yeah, that big block is right under the sun pad. I think intake choices are gonna be limited lol. I think I might put one of my NOS kits on it with a BBC plate and just spray like 125 or 150 at it outta the hole.
#30
Re: Mods for my low performance (310 hp) 454
outriggers,
you have any pics of your boat you could send to me.. Im gonna re-vinyl the graphics on mine and am looking for something different.
[email protected]
you have any pics of your boat you could send to me.. Im gonna re-vinyl the graphics on mine and am looking for something different.
[email protected]