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Posts: 115
| I have a 1996 ranger 681 with a 2011 115 Evinrude etech. The boat is in storage and i cannot remember what prop it has. Its a 3 Blade SS, Running 5750-5900 WOT. Im just wondering what i can do do get a better hole shot, and more top end speed out of the boat. I can get about 40-42MPH with gear and 2 fisherman. Obviously being a 2011 motor, i do not want to re power to the 135 motor.
Thanks! | |
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Posts: 243
Location: South Central Wisconsin | Well, you are more than likely not going to get both. If you want hole shot, go down a pitch. Speed, go up. However, you are probably doing about as good as you can with the rpms where they are at... | |
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Posts: 46
| I have the same boat with a 115 faststrike, which should perform similarly. Here's what I know:
20p raker: fast! Just ok on the hole shot. Need to keep weight to an absolute minimum. 49mph top speed on GPS.
18p raker: better hole shot. Weight is still an issue. 44-45 mph top speed.
Both raker props had a problem with the bow bouncing around a bit -- they were very trim sensitive. If any kind of chop the speed would be compromised because I'd have keep the trim down to keep the bow down.
I tried a four blade prop from Turbo. It was a FX4, and I think a 16p. Good hole shot and a good "hold" in the water. This prop wasn't great, though.
The one I use now is a 17p viper. I really like it, but I can max out the RPMs at 6000 if I'm not careful. The hole shot is incredible. Top speed is about what you're getting (42ish). The prop grabs the water really well. If I could get get an 18p viper it would be perfect, I think. The bigger diameter makes a positive difference, I think.
I don't think you're going to get above 45mph with a 115 and still have decent performance otherwise, but you might do better than you are right now. Hope this helps.
Edited by John23 2/10/2014 8:22 PM
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Posts: 3507
Location: Elk River, Minnesota | Hiya,
I would say if you have gear and 2 people, you are sitting quite well with the numbers as stated. If you remove the 2nd person and their gear, I would bet you are sitting right at 6000 rpms if not a touch over that, which means you are quite close to optimum set up. Max rpm when you are lightly loaded is ideal. That way, when you do get that buddy that comes along with all the gear, you don't have to change props.
Now... depending on the prop and your motor mounting height, you can play a little as well. In most cases, motors are mounted in the lowest bolt hole or one bolt hole up to ensure that the prop (usually aluminum when sold) stays hooked up and gives decent overall performance, but it is usually not the most efficient for the rig. This is where steel props and motor mounting heights come in.
In your case, I'd be curious to know how well the bow trims with your current prop. Can you get the bow up and continue higher and create a porpoise, or does the prop blow out at some point?
The 681 series of boats have a forward mounted gas tank, which makes trimming the bow up a tougher task. That is why the previous poster would have trim issues as the raker series of props are bow lifting props, and perform best when the motor is running within a hundred or so rpms of max on a boat that does not have a huge amount of weight up front. So.. lower rpms overall, and the prop struggles to hold the bow up, thus the rise and fall of the bow. It also shows an affinity for a 4 blade prop to get the prop to hold while at trim, but is not a speed demon by any means. This is a very common characteristic of the older Ranger boats with a bow mounted gas tank. Ask Sled about his rig (He's got a 690 series) and loves his 4 blade!!
So...what possibilities do you have? After determining the exact prop and motor location, The first thing you can try is to move your motor up two more holes and test. What this will do is reduce the amount the bow rises on hole shot, but once on plane and trimmed to your best position, you should see an increase in RPM as you have less motor in the water and the potential that the entire boat is lifted further out of the water. The second thing you can look into are either having vent holes drilled in the prop hub, or go with a prop that is already vented. A vented prop will allow the motor to reach a higher rpm before the prop grabs, popping you up on plane quickly when it does...this comes with a price, though, and it will usually show up if you have to navigate in waters where your rpms are right at that point where exhaust is just about to blow by the holes rather than vent out through them. The boat will tend to surge and lose grip, regain it etc., which gets to be a real pain.
In a nutshell, I feel your speed gains will be minimal as you are close to where most rigs of that weight and size are with a 115 on them. Hole shot can be increased with a vented prop (I don't believe the sst is as it is just a steel prop made from the same basic casting as a stock aluminum). If you can move your motor up, you could potentially go up in pitch, although you will suffer hole shot, but a good vented prop might let you get away with it.
Props to consider: Michigan Rapture comes to mind first, and I wouldn't hesitate to try a raker 18 on it as well, given you can raise the motor, and potentially move some weight more toward the rear of the boat. My gut instinct says 4 blade, though which will really help keep that bow up... I don't recall right off hand, but I believe a mercury trophy plus would be an excellent option for you, given they have an exchangeable hub system in them so you can get the 13 spline hub you need. A 17 pitch, vented correctly would allow you to run your rig at, or just below the highest bolt hole position on the boat and still get good hook-up and bow lifting abilities.
Steve
Edited by VMS 2/10/2014 9:07 PM
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Posts: 1901
Location: MN | Steve,
Don't mean to hijack the thread but you brought up a point I'm curious about. In reference to increasing venting of the prop to improve hole shot, what effect does that have on rpm's and holding the bow up to prevent the rise and fall or bouncing you refer to? We have pretty good hole shot right now but occasionally experience bouncing. Part of this I'm guessing is because we tend to try to cruise at 3800-4000 rpms which is about 34-35 mph. We have a 690 vs and 150 Merc EFI, with a Hi 5 prop. Would venting make the bouncing better or worse? Thanks | |
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Posts: 5874
| Venting should have no effect once you are up on plane and the prop has grip. Venting is for hole shot. The only time it hurts is in the big waves, and you might blow out, and lose grip. | |
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Posts: 3507
Location: Elk River, Minnesota | Hiya,
Shep has hit it well. With some props (most notably mercury props), the vent size can be changed with different inserts in the hub. So...to go off of Shep's information, if the vent holes are too big, the prop will slip like crazy until you get up to mid RPMs, and can be a real bear in rougher conditions....so it is possible that around 3000 or so, you can have problems with the prop grabbing and slipping, thus the rise and fall of the bow. Usually after that, the exhaust gasses are moving too fast to enter the vent holes, thus the prop grabs as it should. That 3000 mark is where many of the grab issues have when the rig is at an optimum set-up. Most times, a smaller vent hole is desired.
Many times, the rise and fall of the bow happens when you are above mid range, but not at full throttle as slower speeds usually allows for lest venting of the blades, increasing grab to the point the prop can't hold it. If you increase rpms, it can settle down. In most cases such as this, a little trim down to keep the bow down helps as the prop is working more to lift the stern at that point. Usually doesn't take much to settle it down.
Trim is a constantly changing part of working your boat. Make a moderate turn, and you will find trimming down a long way is helpful to let the boat carve the turn...especially at high motor mounting heights. Slow down, trim down as well for the reasons mentioned above. My thumb is constantly on the trim and adjusting...especially on long runs with changing condtions as I traverse the lake....
The goofy thing in all of this is boats can be very finicky with the prop that works best for the rig. With my particular motor, I have been quite fortunate in that I was able to dial in quickly, but my previous motor took some time to find the prop that worked best. Ebay was my best friend for a couple of summers, buying and selling as I found props that could potentially work, and all I was out was the cost of shipping.
If you do end up purchasing another prop, it can be beneficial to go to a dealer that has a blue-prop program where you can try different props in different pitches. Usually, though this is tied to the purchase of a prop to begin with, which is where you can incur a $350 to $400 or more cost, but you get the benefit of the demo props to try. Find the one that works, and you are all set.
Steve | |
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Posts: 153
| you could try a 4 blade stainless you wouldnt beliv what a diffrience they make you could also try installing a planing fin and jack plate you wouldnt believe what a diffrience that all 3 make just make sure your motor is turining 5 grand meaning your rpms are at 5 grand when at full throttle if not you are causing damage to your engine ask any experienced mechanic and they will tell you the same also talk to your local e tech dealer maybe they might have some ideas | |
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Posts: 3507
Location: Elk River, Minnesota | Hiya,
I would completely disagree with the fin and the 5000 rpm.
What a jack plate is designed to do is allow the user to raise or lower either manually or hydraulically, which would position the motor at an optimum running height. Combine that with a motor that is propped correctly would put the fin totally out of the water, rendering it useless. All you would have is a motor with 4 holes in it which just reduced the value of the motor by putting something on that is no more than a band-aid to a set-up issue. THE only time to add a fin is when a boat is well underpowered and the motor needs help lifting the rear of the boat and keeping it there...those are the rigs that see a speed gain (maybe a mph or two at most as a general rule) as the lack of power of the motor does not lift the rear of the boat, let alone raise the bow. In most cases, a fin will slow the boat as adding the fin increases drag as it contacts the water.
With the 115 in question here, the fin will never be needed...especially when it is a running a good steel prop.
The Etec 115 is designed to run at a max WOT rpm range of 5500 to 6000 which for best overall performance, the motor should be propped in such a way that a light load would allow the motor to reach 6000 rpm's. This allows for extra people and gear to be loaded on without having to change props. If the motor is propped and below 5500 rpm at full throttle, the engine is working harder than it should, thus lowering the useable life of the motor....which eats up gas as well as the motor is not being allowed to reach is maximum in the power band.
Steve | |
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Posts: 1901
Location: MN | So Shep and Steve, if I'm reading you correctly, I can play with (increase) venting in an attempt to improve hole shot even more, with no concern of it affecting (worsening) bounce? And to control bounce better I may need to look at a different prop, perhaps something like a Rev 4 23 pitch? Thanks
Edited by Propster 2/11/2014 7:34 PM
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Posts: 379
Location: Thief River Falls MN | Rev 4 will be waaaay to much for that motor. Merc Trophy plus 17p may be a better option, has PVS and will wind up quicker due to smaller diameter. Give Ricky at Brainerd props a call, he can help with most any situation and is a good guy to boot.
Edited by toddb 2/11/2014 9:06 PM
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Posts: 1901
Location: MN | I may have the details of the prop wrong. Sled, Lone Stone and a few others with the same rig used a Rev 4 with great success, not sure of the pitch. | |
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Posts: 379
Location: Thief River Falls MN | Just goin off my boat with a 250 which will not turn a 23p Rev 4. 17p maybe on your hull. Had good luck with Trophy plus on last boat with a 150 which had some top end issues. Props suck, sometimes you have to try a bunch to find the best fit, helps to get with the experts on this, I have found...
Edited by toddb 2/11/2014 9:24 PM
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Posts: 1096
Location: Hayward, WI | A Rev 4 won't fit on a 115, only v6 gearcases. If looking at 4 blade stainless defiantly look at a Trophy Plus. | |
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Posts: 115
| it sounds like the prop is the biggest deal in this equation? is there anything that can be done to the motor to add some HP?
i greatly appreciate all the input! | |
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Posts: 3507
Location: Elk River, Minnesota | Hiya,
I don't know of any modifications to the new motors to increase horsepower like you could on older carb models. I'd be real hesitant to mess with an Etec as they are solid the way they are and direct injected.
About the best you can do is prop it correctly, then consider a jack plate if you believe your transom can handle it and the motor.
Personally, I think you are doing quite well getting 42 or so out of it...might get to 44 with some tweaks, and much of that is dependent on how much you want to spend to get those couple extra mph.
Steve | |
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Posts: 5874
| Propster - 2/11/2014 8:59 PM
I may have the details of the prop wrong. Sled, Lone Stone and a few others with the same rig used a Rev 4 with great success, not sure of the pitch.
Sled is running a 175 ProXS, way more power than the 115 ETEC. And as mentioned, the Rev 4 won't fit the 115 ETEC anyway.
Merc Trophy Plus( 13 3/4" diameter) would be an option. As would an Evinrude Rogue (13" diameter).
Do you know the brand and pitch of the prop on it now? I'd try either one of the above in the same pitch, or maybe one less.
Edited by Shep 2/13/2014 8:23 AM
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Posts: 1901
Location: MN | I'm not the one with the 115 Evinrude, I think some folks got confused along the way. Probably my fault for sneaking in a different question on this thread. I have the 690vs with a 150 and was asking whether venting (to increase hole shot) would have any effect on bouncing. Shep and Steve pretty much answered that. I then asked if a Rev4 would help with the bouncing, and someone must have thought I was asking about that prop for the other rig with the 115. | |
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Posts: 574
| You know the gas tank is up front on some of those 690s Propster..?
Mine bounces from time to time, but once I realized it was the gas bouncing it got a little easier to control.. I just give a little extra throttle for a few seconds.. Makes the gas all go to the back of the tank and stop bouncing almost every time.. If not, I just trim down a touch and it will stop..
Edited by Jason Bomber 2/13/2014 8:50 AM
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Posts: 5874
| Sometimes, you just have to drive the boat with the trim, as VMS Steve mentioned. My 1890DS was one of those boats that needed constant attention from my right thumb. | |
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Posts: 1901
Location: MN | Jason Bomber - 2/13/2014 8:45 AM
You know the gas tank is up front on some of those 690s Propster..?
Mine bounces from time to time, but once I realized it was the gas bouncing it got a little easier to control.. I just give a little extra throttle for a few seconds.. Makes the gas all go to the back of the tank and stop bouncing almost every time.. If not, I just trim down a touch and it will stop..
Uh, yea I knew that. And yes the speed up and trim down generally take care of it. | |
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Posts: 383
| @Mahnkal, as the previous owner of that rig, that's a Viper prop. I believe it's pitched in the 13 range. It was selected after a lengthy phone conversation with Ranger's "prop guy." The speed is what it is without going to a 135HO. I maxed at 46 (per GPS) crossing Big Bay on the V in a slight chop. As some others have said on here, the trim button is your best friend on that boat...ride it til you find the sweet spot then let 'er rip. That's a sweet boat...no speed demon, but great fishing platform and I miss that thing a bunch. Good luck to you!!!
Edited by hooked 2/15/2014 7:36 AM
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115 Evinrude going slow.