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payner67

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:confused:I have a mid 90s bombardier celebrity 18' stern drive with a 4 cyl gm in it and would like to get it out of the water faster. It is hard to pull a wake boarder up as its slow plane off - is there a 4.3 liter i can bolt in or mods i can do ? am a car guy and can make that go just not to sure about marine. have been told to prop it but no one seems to actually know what i should put on ?
 
The cheapest way is to change the prop to one with less pitch when towing. Just watch the full throttle rpm.
 
What prop do you have now???

the way the prop thing works is this.


Most three bladed props are identified by diameter and pitch.

Excluding the diameter for now we will discuss pitch.

If you have a 19 pitch prop now for example and you want a better hole shot you need to go down in pitch. typically a one picth change alters max rpm by ~ 300 rpm's and that one pitch is measured in 2 number chages. ( 13p, 15p, 17p 19p, 21p, 23p) p=pitch.

How this realtes to cars as you are a "car" guy is

lets say you are running a 355 posi rearend on you car. You want to get to the finish quicker you would typically ghange your ratio to a 3.73 : 1 or even 4.10 : 1.

If you are running a 19 pitch prop (= 3.55 :1 rear end) and you want to get there quicker as in boating you would want to drop your pitch to a 17p (3.73 : 1) or even a 15p ( 4.10 : 1).

The trade off with doing this is that you can now OVER REV your engine and not reach normal MPH and have to be consous of this and be carefull.
 
Use a 4 blade prop one pitch lower than the current prop; just like kgost described. You'll be able to get on plane quickly but may lose some top end.
 
Excuse me but have you checked to see if the motor is running correctly, with good compression and tuned correctly ?

This boat have extra weight you don't know about ? Like wet stringers, or water hidden in the hull ?

Dirty bottom ?
 
If the engine/drive/prop is in good shape the best/cheapest way to get a better holeshot is to change prop pitch. You are a car guy, decreasing prop pitch is the same as increasing the rear end gear ratio in a car. As you know there are tradeoffs to everything, you will lose a little top end but have more power out of the hole. I had 2 hotrod buddies in HS. They were twins with similar early 70's Camaros. Both had 350 chevy's. One had a 4.56? rear end and the other had 3.55. They were both quick but the 4.56 would give you whiplash and raise the front wheels about 2' off the ground if he borrowed his other brothers wide slicks.
 
Sorry to butt in but I have the same question.I was given a smaller 4 blade prop by a local prop guy and I am getting out of the water quicker.Is it the drop in pitch or the number of blades
 
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