Do I need a high altitude prop?

[Malibudude]

I've been running the OJ 468 but originally had the Acme 537. First noise levels were not affected and I do have the STE tips. While the 468 uses more fuel than the 1235 will it performs better holding speeds and less throttle out of the hole.... YMMV

Whatever you do having a backup prop is a must even a 537 is better than nothing.

[85 Barefoot]

I disagree with the fuel consumption numbers, if anything at lower speeds your engine is working less because of the prop compensating for better low end torque. I ran both and noticed very little fuel consumption difference between the two when wakeboarding and surfing. If you slalom often it would probably consume more fuel at higher rpm's... And I am not following the engine noise difference, its minute if at all noticeable. I dont even have the ste tips and it seems pretty quiet to me.

If you order the boat with the 1235 and dont like it you will have no problem selling it, they are in high demand. Much easier to sell the 1235 over the 1939 --- a less desireable prop for wakeboarding and surfing. Brand new the 1235 is selling for $600... imo, try the 1235 and see how it works for you, sell it if you dont care for it. Very few people switch props after running the 1235.

You said your boat came with the 1939 and you took it off four hours later, right? So, you used your boat in those first 4 hours the same way you do now with the 1235 that you're happy with? Either way, you're still comparing the 1939 with 1235 which is MUCH closer than the 537 and 1235. My 15-20% estimate was 537 to 1235, sorry if that was unclear.

[85 Barefoot]

As for noise, I'm not saying the 1235 is loud. I'm saying by definition you have to spin more RPM at the same speed ie at 20, 25, whatever. No matter what prop you have go drive at 2800 then go to 3200. Of course there's a noise difference. Now consider than noise at the speed you were going at 2800. That's the noise comparison of someone testing sound difference of 537 and 1235.

[Fman]

You said your boat came with the 1939 and you took it off four hours later, right? So, you used your boat in those first 4 hours the same way you do now with the 1235 that you're happy with? Either way, you're still comparing the 1939 with 1235 which is MUCH closer than the 537 and 1235. My 15-20% estimate was 537 to 1235, sorry if that was unclear.

No worries....

Sorry I should have been more clear, I had the 1939 also on my Supra and used it for about a month... I guess fuel consumption is something I dont really pay close attention to... I fill it up and go out and use the boat. When my VLX was ordered I was bummed when it came with the 1939 again... I had to sell the 1939 and buy the 1235. It just never seemed like my Supra or Malibu when I had the 1939 compared to the 1235 was consuming much difference in fuel. I usually burn about 4-5 gallons per hour when we are riding. Definitely consume more surfing than wakeboarding...

Most people who are ordering a brand new boat for $70k + usually dont have huge concerns about fuel consumption, they usually are more concerned about performance. Even it was 10-15% difference, you are talking maybe $20 a day in fuel costs??? From what the OP is describing I think he would be very satisfied with the 1235... but as others mentioned there are many options available.

[Nitrousbird]

I'm seeing some information that doesn't seem accurate at all in this thread:

- 1939 is very much in demand, harder to find than a 1235 used, and sells VERY quickly. Trust me, I tried finding a used 1939 before plunking money down on a new one. 537 is the easy to find prop used.

- 1939 is not an in-between for the 537 and 1235, rather is is an improved prop over the 537, allowing better pull down low while maintaining similar WOT performance. I was under the impression Malibu was dumping the 537 for the 1939 in the new boats.

- There are better choices for many people over the 1235, which is overkill for many people that have it. If you want the grunt of the 1235, most folks would be better served with the 1273. 1273 will give simlar low-end performance of the 1235 without sacrificing as much top speed.

[shawndoggy]

the initial feedback coming in about the 2315 / 2313s are that they are newer technology...designed better against the HP/torque curves on our boats....pull as hard or harder than the 1235s, and loose less off the top end.

Supposedly they pay for those gains in the middle speeds 15-25mph where its ok to give up peak performance. Can anyone comment?

They are four blade 15" cnc'd nibral props. What makes them "newer technology?" Can you point us to a review that suggests that you'd lose less top end with a 15" er?

I'd be very very very surprised if you are going to lose less top end with a 15 x 12 prop than a 14.5 x 14.25 prop. IME a smaller diameter prop will spin faster than a larger diameter prop on the top end. More cup (like the difference between the 1235 and the 1273 that nitrousbird cites) will IME result in lower RPMs at WOT but not higher top speed... at least that's my experience in a different boat with different props.

A boat is just like a truck, except you only have one gear. For some folks who don't load their truck down much, they can climb over the mountains without downshifting. For others who are heavily loaded, they do need a lower gear.

If you cruise AT ALL to get from the ramp to your riding spot, a lower pitched prop is going to result in using more gas, just like driving around with your truck in 3rd gear all the time would. But when it comes time to load it up and push big weight, the lower pitched prop will be much more responsive, just like your truck would be if you drove around in 3rd gear all the time.

Enginenut (from Indmar) posted on here a while back that you want a prop that will get you within 400 rpms of redline at WOT, when the boat is fully weighted for your particular activity. So if you have a monsoon that redlines at 5200 and you want to surf with 3000lbs, you want to make sure that when loaded down with 3000lbs that your motor will hit 4800 rpms. If it won't you need a lower prop.

Edited November 8, 2012 by shawndoggy

[85 Barefoot]

I'm seeing some information that doesn't seem accurate at all in this thread:

- 1939 is not an in-between for the 537 and 1235, rather is is an improved prop over the 537, allowing better pull down low while maintaining similar WOT performance. I was under the impression Malibu was dumping the 537 for the 1939 in the new boats.

its not a direct average but yes it is an inbetween of the 537 and 1235, though its stats are closer to the 537.

[85 Barefoot]

perhaps we should all ask the most important question, what engine?

[dm001681]

Monsoon!

[bamabonners]

so I broke down and called ACME just now. first off, these guys know their stuff. I was looking for something that is between the stock prop and the 1235. I wanted to increase fuel efficiency, but keep some power. We don't typically run huge amounts of weight and we also like to do some riding around. I took notes on our conversation, hope this helps you as well:

diameter is important, for this size boat they recommend that you keep the 14.5" diameter, but go up in pitch. You wil lose a little torque and accelleration, but it will burn less fuel and add top end.

1939 is ok ,but it is 14" diameter.

What he recommends is the 1589, similar to 1939, except 1939 is 14" diameter

1589 has 16 pitch

1939 - 15.5 pitch with slightly less cup

1235 - pitch is 14.25

cup in all 3 is effectively equal eventhough on paper they are different

cup creates bite and is considered a fine tune adjustment to pitch (false pitch)

[Nitrousbird]

Enginenut (from Indmar) posted on here a while back that you want a prop that will get you within 400 rpms of redline at WOT, when the boat is fully weighted for your particular activity. So if you have a monsoon that redlines at 5200 and you want to surf with 3000lbs, you want to make sure that when loaded down with 3000lbs that your motor will hit 4800 rpms. If it won't you need a lower prop.

Read all of the posts in that thread again. All of the important questions went unanswered to the point I'm not buying much of the information that was provided.

[shawndoggy]

Read all of the posts in that thread again. All of the important questions went unanswered to the point I'm not buying much of the information that was provided.

There's only one relevant question in my mind, which is "will Indmar deny a warranty claim based on prop selection?"

Why chance it? We can take nitrousbird's word for it, or we can take Indmar's. I know who the warranty claims go to.

[Nitrousbird]

There's only one relevant question in my mind, which is "will Indmar deny a warranty claim based on prop selection?"

Why chance it? We can take nitrousbird's word for it, or we can take Indmar's. I know who the warranty claims go to.

Chance what? He gave two reason in that thread, one (the overheating issue) I was able to easily disprove with the electric waterpump application of the Indmar Calloway 383. The other is the the cylinder washing by running too rich. This doesn't make any sense at all if the ECM is doing what it should be (going to a proper fuel map based on MAP vs RPM vs TPS).

The only real argument there is if you are lugging the engine which would be an issue. Because the other side of it is they could also deny your claim for over-propping your boat and call it excessive high RPM useage.

[shawndoggy]

Because the other side of it is they could also deny your claim for over-propping your boat and call it excessive high RPM useage.

Has Indmar gone on several forums and warned against that too? I haven't seen it, but that doesn't mean it's not out there somewhere too.

[Fman]

With the Monsoon 350 and the LSV I would definitely recommend the 1235 over the 1939. The LSV is a heavy boat, loaded with 1250 lbs of ballast, the wedge, gear, passengers, it will be liking the ACME 1235. If he was running a larger motor than the 350, I think the 1939 would be more do-able... if the dealer orders the prop from Malibu there will also be no warranty issues with Indmar seeing as it is being sold that way.

Just my opinion, and as you can see I am a fan of the 1235.... been running it for 5 years now and nothing but good things to say about it.

Nitrousbird, Another thing to keep in mind, a 2001 Sunsetter VLX weighs in at 2,900 lbs.... a 2012 LSV weighs in a 4,100 lbs dry. Not to mention the seating capacity in the LSV is 15 people, that is a huge difference compared to a 2001 Sunsetter. The older boats can definitely get away with a different prop than the newer models, just from the dry weight alone.

Edited November 9, 2012 by Fman

[Fman]

I'm seeing some information that doesn't seem accurate at all in this thread:

- 1939 is very much in demand, harder to find than a 1235 used, and sells VERY quickly. Trust me, I tried finding a used 1939 before plunking money down on a new one. 537 is the easy to find prop used.

I had a hard time selling my 1939, it took a couple months and I only got $300 for it... the 1235 was difficult to find, everytime I found one it was sold. I ended up buying a used one for $425 from a private party that never put it on his boat, so basically it was brand new. Nettle Props sells the 1235 for $530 + tax + shipping.

[Tims]

With a monsoon or 6.0 engine on the LSV, the 1235 is a great choice if you use the boat for intended purpose. I am with Fman, the 1939 prop does not perform very well on the new heavy boats. I use mine for a back up.

[bamabonners]

No offense, but you should call the experts at acme. Even they will tell you that while the 1235 is a monster prop, it is not the end all be all prop. Talk to the pros and get the prop that works best for your application.

[Fman]

He is ordering the boat from Malibu, they only offer the 1939 or 1235. Malibu will not custom order props for there boats. At least this is how it was in 2011, maybe they have changed there options.

And I did call Acme, thats why I have the 1235, its what they recommended.

[Tims]

By all means call the folks at ACME. They are great to work with and will allow you to try different props until you find what you like. I have had 4 different props on my boat, from the 1235 to the new 15 inch 4 blades. They all have their strong points, but the 1235 still pulls the best with the Monsoon engine without going really extreme. Probably why it is so popular.

[Nitrousbird]

Nitrousbird, Another thing to keep in mind, a 2001 Sunsetter VLX weighs in at 2,900 lbs.... a 2012 LSV weighs in a 4,100 lbs dry. Not to mention the seating capacity in the LSV is 15 people, that is a huge difference compared to a 2001 Sunsetter. The older boats can definitely get away with a different prop than the newer models, just from the dry weight alone.

I never made any suggestion for the OP's boat - just commenting about the 1939 and the 1235. The 1273 would likely be his best choice.

[85 Barefoot]

And if I may clarify, there is obviouslynumerous props, maybe even 20 options for the OP that could be ideal. The question presented was whether he should get the 1235 as opposed to what came stock. Given stock could be the 537 or the 1939, that's all I was basing decision-making on. OP, the difference between 537 and 1939 as the stock prop could have a big influence on whether the jump to the 1235 makes sense.

[dm001681]

Ok, I just got off the phone with Acme and thought I would share what I learned. First, Jim was awesome, tons of knowledge and took the time to talk it through with me. We discussed the 527, 1939 and 1235 and here is what he said.

• 537 is a great prop for 19'-22' boats
  
• 1939 is a great prop for a lightly loaded 23LSV, meaning no more than factory ballast
  
• The reason they began making the 1939 was because over the years boats in a given length have gotten wider and heavier and the wider diameter prop (1939 vs 537) performed better.
  
• He said that the larger (longer and heavier) the larger diameter prop you want
  

He mentioned that they have been selling a lot of 15" diameter props and wondered from the guys that have experimented with different props if you have found that at a given weight does a larger diameter prop create a larger wake, specifically for wake surfing? Does anyone know?

His suggestion for me personally is to run for a while with the stock prop (I'm assuming its the 1939, still don't have confirmation yet). He feels that is a really good prop for my purposes and if I find that we are loading the boat up more and more I will want to get a 14.5" diameter prop to help push the additional weight. If I find that the stock prop is the 537 (being 13.5" diameter) he suggests I swap for at least a 14" diameter (1939).

Thoughts?

[Brett B]

My boat came with the 1939 and I ran it for several hours before upgrading.

The 1939 would be ok for wakeboarding if you are beginners but will be very sluggish if you run any extra weight (in addition to factory ballast) or if you have a lot of people on board with the factory ballast full. If you want to surf than you will need at least a 750 in the rear locker on the surf side as the stock ballast just isn't enough. The 1939 will struggle to get up to surf speed with that extra ballast but it should do it if you aren't too overloaded.

I would suggest going with the 1273 instead of the 1235 (I have both of these props). They are the same diameter and pitch, but the 1273 has additional cup to it (.150 vs .105). This means that you still get better low end pull, but at wakeboarding and crusing speeds your RPM's will be lower which saves you fuel (2800RPM at 22mph with the 1273 instead of 3000rpm at 22mph with the 1235). It's sort of inbetween the 1939 and 1235.

Top speed on my boat with the 1235 is 40mph pretty much at redline.

Top speed on my boat with the 1273 is 43mph at a couple hundred RPM lower.

I have honestly not noticed much difference in fuel consumption between the 1939, 1273, and 1235 while wakeboarding. Sure the 1939 runs at a lower RPM, but it takes longer to plane out with the throttle wide open which burns more fuel. The 1235 planes out much faster and without having to mash the throttle, but runs at higher RPM while wakeboarding. For our use the fuel differences were negligible, it was pretty much 5 gallons per engine hour while wakeboarding with stock ballast full and wedge down.

If the dealer won't give you the 1273 instead of the 1235, just run with the 1939 and see how it works for you. You should have a spare anyway, so after you have the boat for a while and see how it performs the way you use it, then upgrade to the right prop for you and keep the 1939 as a spare.

Edited November 9, 2012 by Brett B

[[email protected]]

There was a similiar topic a short time ago regarding this very same topic..the major difference was it involved a 1990's vintage Skier vs any of the newer bigger and much heavier Malibu line up. I and others suggested contacting either OJ or Acme, as opposed to WAGs and opinions. Specially since performance is dependent on sooo many variables, and slightly more difficult to measure out on the water. Opinions are great (but when props are now $600+, guessing can be expensive), but the experts actually know their product line best, although someone on the previous topic considered themselves an "expert" on the subject..ha ha There was a name thrown out...some Bill Big Dog fella, that may be a great place to start, and see what his suggestion(s) are. Or maybe Jim at Acme...I have learned quite a bit just from chatting with him about issues I had/have with my LXI and the LS3 option. Although I would not consider myself an expert on props as others do, just offering some sound advice.

Each boat owner experiences, expectations and observations are going to be different, just as their use, location, sport selection, etc. will vary.. Just as dms' comment pointed out, only he knows how and where his boat will be used (and he may not even know, or they may even change)...and all those and more factor in when selecting the right prop for your boat.

Even the owner's manual is misleading, as with my LXI. In one location it states the 13x13 is the std prop, when in another location within the same manual, it states the 13X12 is the std prop!! Probably the same for other boats too.

Anf not sure if what engine option he has, as that makes a difference. My LS3 does not have the same low end TQ as the monsson does, so the engine is a huge factor/component in prop selection.

Edited November 9, 2012 by [email protected]