Do I have the right prop? High Five Question

[jeff.nelson83]

Ok here we go.

1992 cobalt 206 20ft 5.7 v8 alpha one gen 2 drive with high five 17 pitch prop. No ballast and 4 people.
Used for wakeboarding and driving to wakeboarding spot. Pulls wakeboarder very easily but I dont know if i would get better results with a 19P.

1) Issue, I am overreving the boat at WOT. WOT for my engine is 4200-4600 and I am at 4800. Is the sacrafice i have to make to pull wakeboarders easily? Or am i just using the wrong prop. I dont care to run my boat at WOT but i thought i would ask all of you.

 

[KYsean]

Re: Do I have the right prop? High Five Question

Ok here we go.

1992 cobalt 206 20ft 5.7 v8 alpha one gen 2 drive with high five 17 pitch prop. No ballast and 4 people.
Used for wakeboarding and driving to wakeboarding spot. Pulls wakeboarder very easily but I dont know if i would get better results with a 19P.

1) Issue, I am overreving the boat at WOT. WOT for my engine is 4200-4600 and I am at 4800. Is the sacrafice i have to make to pull wakeboarders easily? Or am i just using the wrong prop. I dont care to run my boat at WOT but i thought i would ask all of you.

19P would be much better for your engine.

 

[emilsr]

Re: Do I have the right prop? High Five Question

The "right prop" for watersports (or heavy loads) will usually put you on the rev limiter (if you have one) under more "normal" conditions. Nature of the beast...analogous to running a higher numerical final drive in your drag car for better accelleration. A 19p will drop the revs down into the recommended range but you're probably going to lose a bit of holeshot. If your current prop is working for you in tow mode, I'd just throttle back when not towing. 4800 isn't going to kill your 5.7 anyway....assuming the tach is correct....but it would be better if you didn't run it that fast.

 

[jestor68]

Re: Do I have the right prop? High Five Question

I don't believe that you'll sacrifice any perceivable pulling ability by switching to a 19" prop that will allow the motor to operate within it's recommended rpm range.

You'll save some $ by purchasing a Quicksilver QST 5 prop if you want to run a 5 blade.

I recommend a 14.5 X 17 4 blade. The extra inch of diameter will bring the rpm down, while still providing acceleration rivaling a 5 blade.

I encourage a visit to the Mercury prop selector. You boats dry weight is listed as 2700 lbs.

 

[not enuf toys]

Re: Do I have the right prop? High Five Question

interesting....I run a 19p high five with a similar setup (5.7lx alpha 1 gen 2) and I am at 4800 and thinking of going to 20/21.

I have a feeling my thunderbolt v ignition is limiting my revs to 4800 as my 21p raptor also runs at 4800.

what ignition do you have? I would think 17p would sent you above 5200

 

[jeff.nelson83]

Re: Do I have the right prop? High Five Question

Well i don't even know if my boat has a rev limiter so I am the rev limiter. RPM's went to 4800 and i pulled back the throttle. I'm not looking for top end and i dont drive my boat WOT, all we care about is sking wakeboarding and driving 30mph across the lake. Not going to buy a tow boat because i dont have that much disposable income.

 

[not enuf toys]

Re: Do I have the right prop? High Five Question

gotcha about WOT and top end across the lake, i was just going off of your origional post/question :facepalm:

...I dont know if i would get better results with a 19P.

1) Issue, I am overreving the boat at WOT. WOT for my engine is 4200-4600 and I am at 4800. Is the sacrafice i have to make to pull wakeboarders easily? Or am i just using the wrong prop. I dont care to run my boat at WOT but i thought i would ask all of you.

 

[jeff.nelson83]

Re: Do I have the right prop? High Five Question

The "right prop" for watersports (or heavy loads) will usually put you on the rev limiter (if you have one) under more "normal" conditions. Nature of the beast...analogous to running a higher numerical final drive in your drag car for better accelleration. A 19p will drop the revs down into the recommended range but you're probably going to lose a bit of holeshot. If your current prop is working for you in tow mode, I'd just throttle back when not towing. 4800 isn't going to kill your 5.7 anyway....assuming the tach is correct....but it would be better if you didn't run it that fast.

This answered my question. I didnt know if using to low of a pitch would hurt my hole shot or pulling a skier or cause some other problem that i would not know about.

Thank you eveyone for your help!