Which way...prop or setback

[studlymandingo]

I have an 18'6" Winner Center Console with a 1986 150 Mariner V-6. I am currently running a 21p stainless Rapture prop that is vented.

With 2 adults an 85lb dog, 40-45 gallons of fuel, and some ice and liquids in a cooler, I am getting 43-44mph GPS. The RPMs are right at 5200+. I feel that I should be trying to get a little closer to the 5800 RPM range. My hole-shot is fine, I have Smart Tabs installed and she jumps the wave and is on plane in seconds. The A/V plate is level with the bottom of the boat, I don't experience any prop blow when trimmed out fully, and I'm getting 15-18 psi on the water pressure.

I'm thinking a setback/jack plate may be good for my rig. I have seen this hull come from the factory with a 12" setback so I think it might be good for the handling in rougher water anyway.

My question to you guys is... What do you think, should i step down to a 19p, or should I be looking at raising the motor and possibly stepping it back off the hull a bit?​

 

[Dhadley]

Re: Which way...prop or setback

Everything you mentioned says the motor / prop is asking to be raised. That will raise the rpm and increase efficiency. It seems you're looking for help carring the nose since you mentioned full trim and since you've seen the same hull come with a lot of setback that indicates they use the setback to help hold the nose up. I think you're headed in the right direction. I'd try raising the motor without the jackplate just to get a baseline.

With todays prop technology, the AV pale being level with the bottom is considered a low mounting. Once you get the motor up and back you may end up with a bigger prop rather than a smaller one.

 

[studlymandingo]

Re: Which way...prop or setback

Thanks for the reply; that is kind of what I was thinking. I may try going up a hole or two first to see where that gets me. I like the idea of a jackplate that has a good bit of setback. Seems like the boat will handle a little "longer" if the motor is back further.​

 

[Dhadley]

Re: Which way...prop or setback

The more set back you have the further back the lift point or fulcrum is and the more the bow will carry. To a point. You can go back far enough that the boat starts to handle wierd.

 

[studlymandingo]

Re: Which way...prop or setback

I was thinking of somewhere around a 10" setback.​

 

[Dhadley]

Re: Which way...prop or setback

If they've come from the factory with 12", then 10 is OK too. You can always add 2" spacers.

 

[studlymandingo]

Re: Which way...prop or setback

That was kind of my reasoning. I figure it would be easier to add than try to subtract if I started with a 12".

The boat handles well right now, especially with the recent addition of the hydraulic steering; it just feels like it could do a little better.​

 

[studlymandingo]

Re: Which way...prop or setback

I did it! I ordered the 10" jack plate yesterday. Now I have to wait for UPS (that's the part I hate). I'm going out this weekend to do some testing as-is; once the jackplate is installed, I'll run the rig under similar conditions and post the results. I'm stoked!​

 

[CalicoKid]

Re: Which way...prop or setback

What kind of jackplate did you order?

 

[studlymandingo]

Re: Which way...prop or setback

It is a 10" Hi-Jacker Pro HP.

It was sent out yesterday; I'm on my way out to do some before testing today so I can see the difference.