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Member
2020 Ranger 1850MS set-up question
First off, this isn’t a bass boat hull. It’s more akin to a multi-species or walleye hull.
Secondly, the motor is hardly broken in (10 hours).
Motor = 2019 Mercury 175 ProXS Fourstroke
Prop = Tempest Plus 19P
Prop to Pad = 6.25” (pretty typical for this type hull)
Two guys + gear = 550 pounds
Fuel = 30 gallons
Elevation = 2,218’
Maximum RPM = 5,610 per MercMonitor
Maximum Speed = 47.8 MPH per GPS
The maximum recommended RPM range for the 175 ProXS is 5,400~6,000.
Should I make some changes to get my maximum RPMs from 5,600, up closer to 6,000?
If so, would going from a 19P to a 21P be the logical first step?
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If you increase pitch, you decrease RPM.
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Member
I misspoke. I meant to say: Should I go from a 19P to an 18P or 17P?
Thanks for pointing out my error.
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Member
I would leave it alone if it were me. It sounds like it's pretty well dialed in now. Even if you got the rpm's up to 6,000 you are probably not going to run it at WOT all the time.
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You always want to be at the top of your rpm range.
Why?
Everything works better.
Holeshot is quicker
Acceleration is quicker.
Far less strain on bearings and lower unit gears.
Good news you can send that tempest to Josh at Steve’s prop on fork. He can tune it to do whatever you want.
Pat Goff
Two degrees from center
of nowhere.
Smithwick TX.
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When we you do that with a Tempest Plus 19 P prop will it end up being a 18P ( a bit slower) or just a better all around 19P ?
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It's all about prop slip and handling a fishing load.
A 18" prop working at 10% slip is going to be faster than a 19 running at 15%.
Best way it was explained to me, you get one gear in your car. You can be quick, or you can be eventually fast. Which one is going to be harder on everything, the gear that strains everything more or less?
Pat Goff
Two degrees from center
of nowhere.
Smithwick TX.
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Thank you
I've got a 19P Tempest that's running around 6% slip and I'm thinking of sending it in to have it worked so I can get more RPM (200- 300)
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Member
My prop slip calculates to approximately 12%.
Isn’t that a bit much?
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Not really, 12% is about average. You see guys claiming 6% or some other incredible number, they aren't real. Anything at or below 10% are Allison type numbers, you're not going to get that in your typical hull.
Your answer is actually pretty easy, send it to Josh at Steves prop on Fork, give him your current results, and what you want out of it, and that's exactly what you'll get back.
Pat Goff
Two degrees from center
of nowhere.
Smithwick TX.
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Member
I ran my boat with a Mercury Revolution 4. I really like the Rev 4 and have run one on multiple Ranger Reata series models. The hole-shot, stern lift, low speed handling and control @ speed are far better than the Tempest Plus. Anyway, here are the results:
Motor = 2019 Mercury 175 ProXS Fourstroke (1.85 gear case)
Prop = Rev 4 - 17P
Prop to Pad = 6.25” (pretty typical for this type hull)
Two guys + gear = 550 pounds
Fuel = 30 gallons
Elevation = 2,218’
Maximum RPM = 5,520 per MercMonitor
Maximum Speed = 45.1 MPH per GPS
As you can see, as completed to my original post with a Tempest Plus 19P, I lost a few RPMs, lost about 3 mph and cut the slip in half.
I’d really like to get another 400 RPMs on top end. This might be achieved with a Tempest 17P or a Rev4 15P (if they made one).
Any thoughts or suggestions?
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A Turning Point Dual Geometry 17P stainless should get rpms closer to 6k with better holeshot and handling.
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You went from a 3 blade to a four blade so you lost rpm's and speed. Have the 19 tempest worked and you'll gain speed and a few rpm's like Pat said.
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But he went from a 19 P to a 17 P. Shouldn't it have been about the same RPM ?
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I had some of the same concerns when I got my 175 four stroke. Ended up dropping my prop pitch from 25 to 23. I was still not getting 6000 rpm so I took the prop over to Steve’s Prop Shop. Got the best advise ever from Josh and walked out the door reassured that my rig did not need any prop work. Sometimes we just over think things.