Going down a size in pitch

[Bassinkorea]

My current set-up and stats.

Triton TR185
150hp Optimax
23p prop
WOT = 5,200rpm & 57mph
Manual jackplate (which I messed with in different positions a few years ago to try and get more rpm's)

Hole shot is really quick with just me in the boat with full fuel tank and fishing gear, and still great with a fishing buddy with me. I don't have any problems with the current set up. However, I feel I should get a few more rpm's and a bit more top speed for those "got to get to the best spot first" during tournaments.

My question is, what would happen if I dropped to a 22p or even a 21p prop?

[Princeton_Man]

Other than manufacturers our boats are close in specs. Mine may be a bit heavier. I normally run a 23p 4 blade that's been b&b.  With full tanks, a very full load, and just me running at 5700 I'm at 58-60mph. I can get about 62 with my 24p 3 blade.
Your speed sounds about right. Are you reading the engine rpm on your boat's tach or from your electronics? My analog tach reads 150-200 rpms less than my Garmin Echomap and connecting the motor to the computer confirms that.

When the water warms up, your rpms will go up too. Unfortunately, speed doesn't.

[Mike Cork]

All boats are a little different so you'll have to play. Using P_M's intel is a good start.

In general going down a pitch means higher RPM's, just don't get to low and you over rev getting out of the hole. Do you know how high your RPM's get coming out of the hole now? Your top end RPM suggests that you can safely go down a pitch and might increase speed if you don't start to slip.

[Bassinkorea]

Are you reading the engine rpm on your boat's tach or from your electronics? My analog tach reads 150-200 rpms less than my Garmin Echomap and connecting the motor to the computer confirms that.

When the water warms up, your rpms will go up too. Unfortunately, speed doesn't.

I have a MercMonitor installed so I'm sure those numbers are accurate. Prior to installing the MM I had the original analog tach and had pretty much the same numbers.
I have noticed that these rev numbers are almost the same during warm and cold water temps, maybe an additional 500rpm's at best.

[Bassinkorea]

Do you know how high your RPM's get coming out of the hole now?

I believe somewhere in the region of 3000rpm, but I'll have to confirm that next time I'm out.

[Mike Cork]

That's about right, should provide a great hole shot.

TO get more top end RPM isn't magic, we all know the higher the motor the higher the RPMs. The smaller the prop the higher the RPM's. But there is a balance in there that provides the least slip and the fastest ground/water speed.

[Princeton_Man]

I have a MercMonitor installed so I'm sure those numbers are accurate. Prior to installing the MM I had the original analog tach and had pretty much the same numbers.
I have noticed that these rev numbers are almost the same during warm and cold water temps, maybe an additional 500rpm's at best.

I see about an additional 200-300rpm once the water warms up.

It sounds like you're just needing to find that sweet spot. It would be awesome if you could find someone local with a prop you could test. Maybe a Fury instead of a Tempest would make the small amount of difference you're needing.

[Bud Kennedy]

You know I am not a fan of the swap a prop routine for finding the sweet spot unless there is a true prop specialist involved.  Your boat seems to be performing about where it should but a few more rpms would be to your advantage.  I remain fixed on the basic premise of motor height set up as confirmed by a correct prop to pad measurement.  After making height adjustments (if required) then that is when I would engage the services of a prop professional.  However it remains to be said that buying a new prop or having custom prop work performed is a pretty pricey deal for a couple lousy MPH.

[Bassinkorea]

Like I said initially, overall I am very happy with my current set-up, it's just that I know I could get more rpm's.

Prop swapping around these parts isn't a practical option I'm afraid for several reasons, one of which I might write up in another thread.

Bud, I did set the pad height several years ago and didn't want to go any higher due to the water pressure dropping too much.

Thanks for all your input fellas, learning all the time 

[Donald Garner]

Steve, good luck on getting your boat setup to run like you want it too. 

[Bassinkorea]

Steve, good luck on getting your boat setup to run like you want it too.

Thanks Donald. Actually these day I am in a money saving mindset due to being out of work, so I usually plod around in the 4000~4500rpm range, but it would be nice to have the full 6000rpm should I need it.

[Pacific NW Ron]

Do you have a dealer around you that would let you borrow a couple props to see what works best for you?.  That would be better than buying props.  I know there are some dealers that will let you use a prop. 

[oldgas]

Bassinkorea, I was in the custom high performance bass boat propeller business for a good number of years (now retired). I dealt with countless people who spent countless dollars to gain one or two MPH and 9 times out of 10, we ended up setting the boats up for the best "overall" performance.
Bud and Mike's reply (among others to a degree) pretty much sums it up best based on the limited info you have here.
Ther's a LOT to consider but the bottom line always comes back to; "What are your primary goals for the 85 to 90% of time what you use your boat for"?
Many many people get hung up on pitch and pitch is just one building block/tool toward achieving "overall" performance.
If your bottom line goal is to get the most out of this boat, AND you are willing to spend the money, someone here already replied the best advice........employ a professional.
Good luck.

[Bassinkorea]

Do you have a dealer around you that would let you borrow a couple props to see what works best for you?.  That would be better than buying props.  I know there are some dealers that will let you use a prop.

Ron, as far as I know there are no prop dealers here at all. There's just not ENOUGH of a market here.

[Bassinkorea]

Bassinkorea, I was in the custom high performance bass boat propeller business for a good number of years (now retired). I dealt with countless people who spent countless dollars to gain one or two MPH and 9 times out of 10, we ended up setting the boats up for the best "overall" performance.
Bud and Mike's reply (among others to a degree) pretty much sums it up best based on the limited info you have here.
Ther's a LOT to consider but the bottom line always comes back to; "What are your primary goals for the 85 to 90% of time what you use your boat for"?
Many many people get hung up on pitch and pitch is just one building block/tool toward achieving "overall" performance.
If your bottom line goal is to get the most out of this boat, AND you are willing to spend the money, someone here already replied the best advice........employ a professional.
Good luck.

I thank you for sharing your professional opinion, all taken on board and appreciated 

[Bassinkorea]

Update.

I managed to get my hands on a very used 21P Mirage Plus prop.
I ran it on my motor for a few weeks whilst I sent my current 23P Tempest Plus prop away for some minor repairs.

The hole shot with the 21P was quite a bit quicker which I liked.

My RPM's were up considerably, reaching 5,700rpm. This is the highest I have had this motor run at, and the motor obviously sounded a lot different which I wasn't used to and didn't like 

Top end dropped by a few MPH.


Now I have my 23P back on the boat and I am very happy with it, and I now have the 21P strapped into the rear compartment as a spare. I don't need to mess around with my set-up as I have concluded I am more than happy with the original set-up.