Difference between props

[Squire]

I am running a 2005 20' Regal bowrider powered by a 350 Mag MPI with a Bravo One 1.5 outdrive turning a 14x19 Vengeance SS prop. The suggested WOT range is 4800-5200 and I get 52 mph at 4900 rpm under normal load - 4 persons plus gear. I know I fall in the range but there is room for improvement and I am willing to spend my money toying with optimizing my setup. I use this boat for cruising and watersports so I am looking for the best combination for all around performance.

I am considering a 14x17 4-blade SS Turning Point prop and this is where my questions lies. TP manufactures two of these 4-blade SS props - one is the 14x17 31501730 PA-1417-4 and the other is 14.5x17 31521730 VO-1417-4.

Aside from the obvious 1/2" difference in diameter, does anyone know if there are any other differences such as angle of rake, blade geometry, cupping, blade surface area etc.. that separate these two models? The TP website and hours of searching online have yielded no answers. I would appreciate any info that helps me make an informed decision.

 

[Maclin]

Re: Difference between props

What exactly are you looking to improve? Low end? Is it hard to pull skiers up now? Is it hard to stay on plane when towing tubes or boards? or Top end? Does your buddy's boat go 53mph?

The numbers you gave indicate the current prop is a good balance in my view, so it is hard to give advice not knowing where you seek improvement. If all else is equal and you go to a 17p AND the rpms go to 5200 you will lose 3 mph on top end and gain some oomphh at low end.

Just an opinion here, but it seems to me that your combo should be able to over-rev now with the 19p. Is 4900 all it will do?

 

[kmarine]

Re: Difference between props

can you see about a demo prop program from your local prop shop or dealer? my prop guy lets you try demo props before you bring home your new permanent performing prop.

 

[Squire]

Re: Difference between props

What exactly are you looking to improve? Low end? Is it hard to pull skiers up now? Is it hard to stay on plane when towing tubes or boards? or Top end? Does your buddy's boat go 53mph?

The numbers you gave indicate the current prop is a good balance in my view, so it is hard to give advice not knowing where you seek improvement. If all else is equal and you go to a 17p AND the rpms go to 5200 you will lose 3 mph on top end and gain some oomphh at low end.

Just an opinion here, but it seems to me that your combo should be able to over-rev now with the 19p. Is 4900 all it will do?

I keep my boat at a lake that is two hours drive from home and home is an hour drive in the other direction from any marine store/dealer (Vancouver, BC, Canada). I bought the boat second hand and it came with only the one prop. I want a spare prop in case of unforeseen events and since I need to get one I'd like to try to improve the performance of the original - if possible. If it helps you make constructive suggestions, or to answer my specific question regarding the difference between the two TP props, my buddy's boat doesn't go faster than mine.
I agree after reading other posts that the setup I have should be able to turn that prop faster. People seem to be turning higher pitched props faster with comparable power to weight ratios.

 

[Squire]

Re: Difference between props

can you see about a demo prop program from your local prop shop or dealer? my prop guy lets you try demo props before you bring home your new permanent performing prop.

The dealers/shops that have demos in Vancouver, BC, Canada are limited and the ones that do didn't have an appropriate model for me to try.

 

[Maclin]

Re: Difference between props

I meant no offense, rather tried to give examples of where you want to improve. So, do you want to go faster (and lose some pulling power out of the hole) or do you want to pull out of the hole better and sacrifice some top speed. You are balanced between the two (low end and top end) and propped about right now if 4900 is your top rpm.

What altitude do you boat at?

 

[Squire]

Re: Difference between props

I meant no offense, rather tried to give examples of where you want to improve. So, do you want to go faster (and lose some pulling power out of the hole) or do you want to pull out of the hole better and sacrifice some top speed. You are balanced between the two (low end and top end) and propped about right now if 4900 is your top rpm.

What altitude do you boat at?

No worries, I should have explained that I wanted to carry a spare because of the remote location in the first place and because I need another prop I might as well try to improve performance or at least provide a choice in performance. The lake I am on is about 850' above sea level and about 12 miles long by 1.5 miles wide and I mostly cruise at about 3000 rpm or 30 mph. I feel that the extra 300 rpm to get to recommended max WOT is possible if not necessary and the benefit one way or another from this change would be welcome. If you have any other prop suggestions I would be all ears but I have located the TP props I mentioned at very competetive prices.

 

[Maclin]

Re: Difference between props

If all else is equal and you go to a 17p AND the rpms go to 5200 you will lose 3 mph on top end and gain some oomphh at low end.

This part of post #2 shows what you can expect moving to a 17 from a 19. Regarding different styles of props doing something different then all I can say is much of that is trial and error. Hopefully some others that have experience with those props in your exact boat/engine/drive will see this and contribute their stories.

 

[90stingray]

Re: Difference between props

Removed post

 

[Squire]

Re: Difference between props

This part of post #2 shows what you can expect moving to a 17 from a 19. Regarding different styles of props doing something different then all I can say is much of that is trial and error. Hopefully some others that have experience with those props in your exact boat/engine/drive will see this and contribute their stories.

Thanks for your responses. I understand that it is really trial and error but it would be nice if the various manufacturers described the specific differences between their prop models. This would at least narrow the margin of error when spending money on what is essentially a guess.

 

[Maclin]

Re: Difference between props

B bring
O out
A another
T thousand

 

[Squire]

Re: Difference between props

Just an update on my prop hunt: I found a guy on Craigslist who had both a 14x19 Enertia and a 14x17 Rev 4. This guy had tried both on his boat for about 30 mins each but they were too much prop for his setup. He bought them brand new and because he was local, I made him an offer for both subject to an inspection confirming their condition. I was not disappointed and drove away from our rendezvous with both of them at about half of retail value. Now I have to admire them on the coffee table until the spring when I can get back on the lake again or when the wife tells me to put them away

 

[V153]

Re: Difference between props

If the wife gives ya any flak about yer newfound treasure(s)? Just whack her upside the head with one, that usually shuts em up for awhile ...

B best
O of
A all
T times

 

[jestor68]

Re: Difference between props

Where did you get the info that your 2005 350 Mag is rated for 5200 rpm? That rating doesn't take effect til 2009. Your year shows 4600-5000 rpm; which means you're right on the money.

Your motor has seven years of (hard?) use on it. Do a compression check and you might find out why your buddy's boat can out run your's.

Based upon your present rpm, I'd suggest a cheap aluminum prop as a spare.

 

[Squire]

Re: Difference between props

Where did you get the info that your 2005 350 Mag is rated for 5200 rpm? That rating doesn't take effect til 2009. Your year shows 4600-5000 rpm; which means you're right on the money.

Your motor has seven years of (hard?) use on it. Do a compression check and you might find out why your buddy's boat can out run your's.

Based upon your present rpm, I'd suggest a cheap aluminum prop as a spare.

This boat is absolutely pristine with a total of 95 hrs on it and I still don't have a buddy with a faster boat

You experts are really a tough crowd; is it really a character flaw to want to try better technology in a prop than the Vengeance?

Thanks for the WOT info. Ill be looking to confirm this as I have apparently been given the wrong info.

 

[jestor68]

Re: Difference between props

Your initial idea didn't represent better technology. Since picking up a couple of Mercury props, you're close to your goal.

 

[Squire]

Re: Difference between props

Your initial idea didn't represent better technology. Since picking up a couple of Mercury props, you're close to your goal.

That was the reason behind my original post/question: What are the differences between the props that makes them better than their competitors? I guess manufacturers protect this information from competitors but it prevents the consumer who wants to make informed choices from being able to tell the difference. Stats listed by manufacturers do not include rake angle, blade area, let off etc... No information is provided for comparison and trial and error is expensive when it comes to props.

I was trying to find better technology at reasonable prices. Now I am starting to understand that you get what you pay for and that finding the Mercury props the way I did at the price I paid was fortuitous. Just a visual comparison between the Vengeance and Enertia says a lot.

Thanks

 

[Maclin]

Re: Difference between props

Regarding "better", that term is very subjective and you have not specified what part of your boat's performance you want to make "better", just sayin'.

 

[Squire]

Re: Difference between props

Regarding "better", that term is very subjective and you have not specified what part of your boat's performance you want to make "better", just sayin'.

For starters I found some test results on Boattest.com that showed 5100+ rpm on 2005 and older 350 mag mpi models and was under the impression that I had room to pick up 200-300 rpm. I have since been corrected in this thread.

I was willing to try to find either better handling via a 4-blade prop - the lake can really whip up in the afternoons - or more top end with a superior 3 blade. I need a spare prop in any event and I would have picked up the first good deal I could find in either. I believe that I now have these options in my possession although the Rev 4 may spin too fast for my 2005 350 mag.

April is a loooong way away

 

[Squire]

Re: Difference between props



It turns out that sites displaying WOT data for my 2005 350 Mag MPI may have been incorrect. The sticker from the factory on my engine reads MAX. W.O.T. RPM.......4800-5200

What this means to me is that both the Enertia 14x19 and the Rev 4 14x17 that I recently acquired will perform well on my setup. They will have their own contrasting applications but I am looking forward to trying both.