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Prop question

Dirty Daytona

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I have an eliminator 27 Daytona with a stock 496 HO with a 24 pitch prop. The most RPM I ever got even with fairly empty gas and just me and my wife in the boat was 5100. The best top speed I ever got was 70 mph.
So I chunked the prop this weekend and borrowed my friend’s 22 pitch prop to get me through the weekend. With the 22 pitch, 90 gallons of gas and 7 people on the boat I was hitting the rev limiter at 5300 RPM and running about 60 mph with all that weight.
My question is what pitch prop should I buy? If the 24 pitch with a light load was only letting me hit 5100 RPM should I try a 23 pitch? Suggestions? Comments?
Also, with the 24 pitch it pulled out of the hole fine but I’m thinking I need a prop to let me reach as much RPM as possible correct?
 

Joepump

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Talk to Augie at Cutting Edge in Santa Ana, I would try one of his 5 blades, I would start with a 23p
 

Andy B.

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I think 70 with a 496 for 27ft is pretty good but what do I know I have a v hull lol! 2FF could probably tell you..
 

NicPaus

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Labbed 24 will give you a few more rpms than the stock 24.
 
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BajaMike

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If you can’t get to red line RPMs with a normal load of people, gas, beer, water, ice and toys, you are overpropped.

“Labbing” a prop is a very general term. The prop shop you are using to “lab” a prop (one that is close to what you want) should ask you want you want to improve......top speed, RPMs, hole shot, lifting the stern or lowering the stern.......etc. A normal 23p sounds like it would work for you.

Number of blades and diameter of the prop add some more confusion.
 

NicPaus

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I don't think they make a bravo 1 23. It's a rev 4 in 23 which I have. Easier to spin my 24 bravo 1. You can order a mercury labbed 24 from Mercury not just have a shop lab it where they can dial it in for your application.
 

HavaToon

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More importantly your 496 HO has a max rpm of 5000 with 5150 being the rev limiter. So either your tach is off or your rev limiter has been raised if you’re seeing 5300.

I had a 29’ Magic Wizard with a 496 HO and a 24 pitch labbed B1. Loaded up I was 4900 rpm and 65 mph, best was 72 mph at 5100 rpm.

I’d say the 24 you have is perfect or you could lab it.


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Dirty Daytona

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I have no idea what the prior owner did to the 496 but I know for sure it was showing 5300 on the dot with the 22p prop.
More importantly your 496 HO has a max rpm of 5000 with 5150 being the rev limiter. So either your tach is off or your rev limiter has been raised if you’re seeing 5300.

I had a 29’ Magic Wizard with a 496 HO and a 24 pitch labbed B1. Loaded up I was 4900 rpm and 65 mph, best was 72 mph at 5100 rpm.

I’d say the 24 you have is perfect or you could lab it.


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02HoWaRd26

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You don’t want to be spinning that motor to 5300, I’d be more interested in a 24p then have labbed slightly, by someone after you take the stock prop and test and collect data.
I got a new CE from Auggie Saturday used Saturday and Sunday now sending back to him so that he can make a few further changes to it.
 

HavaToon

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I have no idea what the prior owner did to the 496 but I know for sure it was showing 5300 on the dot with the 22p prop.
I believe you that your tach was showing 5300, not sure I believe the tach is 100% accurate.

Either way the 22 is to small if you were loaded and on the limiter, I’d get another 24 and call it a day.

If you wanted to experiment I’d suggest trying a Hill 23p 5 blade. Like this one, it sold but you could call Hill.
IMG_2009.jpg



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Dirty Daytona

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I believe you that your tach was showing 5300, not sure I believe the tach is 100% accurate.

Either way the 22 is to small if you were loaded and on the limiter, I’d get another 24 and call it a day.

If you wanted to experiment I’d suggest trying a Hill 23p 5 blade. Like this one, it sold but you could call Hill. View attachment 770537


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Havatoon I agree, I was running fine with the 24 and I think I’m overthinking this. I’m going to get another 24 and keep it safe at 5000 RPM’s.
 

Dirty Daytona

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So either my tach is off or the prior owner had the Ecu modified but either way I don’t want to blow this pile up!!!! Thanks for the help guys!!!
 

BajaMike

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Looked this up, sounds like your 24p is about right.




5FC92F33-ADF3-46F7-BA84-954570885E66.jpeg
 

Dirty Daytona

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That’s what’s left of my 24!!! Lol. I have no idea what I hit because I didn’t feel a thing.
 

USMC2010

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I have a 496mag ho and during the summer run a b1 24 pitch. I can run just shy of the rev limiter and it pulls out of the hole good with any amount of weight. In the winter it will ping the limiter with no additional speed. During the winter I run a B1 26 pitch, runs 73 and just shy of the rev limiter. I tried the 26 during one summer and it just started out too sluggish. Other than going prop testing and getting all crazy it sounds like your original prop is a good number for overall use.
 

Dirty Daytona

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I have a 496mag ho and during the summer run a b1 24 pitch. I can run just shy of the rev limiter and it pulls out of the hole good with any amount of weight. In the winter it will ping the limiter with no additional speed. During the winter I run a B1 26 pitch, runs 73 and just shy of the rev limiter. I tried the 26 during one summer and it just started out too sluggish. Other than going prop testing and getting all crazy it sounds like your original prop is a good number for overall use.
Thank you sir. I appreciate the information.
 

02HoWaRd26

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I believe you that your tach was showing 5300, not sure I believe the tach is 100% accurate.

Either way the 22 is to small if you were loaded and on the limiter, I’d get another 24 and call it a day.

If you wanted to experiment I’d suggest trying a Hill 23p 5 blade. Like this one, it sold but you could call Hill. View attachment 770537


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My new Livorsi’s and the VesselView are about 150-200 off at upper rpm, seems at 3500 on tach VV says 3340-3370 and at 4500 on tach i see 4270-4300 on VV
 

robby dmax

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I would say stick with the 24 at 5000rpm..as stated before rev limiter is 5150 on a stock 496 ho ecm
 

BajaMike

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My new Livorsi’s and the VesselView are about 150-200 off at upper rpm, seems at 3500 on tach VV says 3340-3370 and at 4500 on tach i see 4270-4300 on VV

I never thought about a tach being off that much. Good info. I always trusted the tack.....maybe wrongly sometimes. 5000 and 5200 make a big difference.
 

zx14

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Just a fun fact here:

If you run dirty Daytona’s numbers in the prop calculator, at 70 mph 5100 rpm 1:5 gears 24p he has a slip of 9.4

I’ve been working with Alexi on my tune, so Sunday, “in glass above sandbar” I ran 106mph at 5600 rpm 1:36 gears 30” B1 (labbed, but only balanced and sharpened) and get the same prop slip.

Now, we all know, I have a whole lot less boat touching the water at this speed.
I’m guessing, my x dimension is higher, thus more slip compared to the drag? I don’t know , it’s all farking majic.

DD is a 27’ Daytona, I’m a 26’ (same bottom on both)
 

Dirty Daytona

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Just a fun fact here:

If you run dirty Daytona’s numbers in the prop calculator, at 70 mph 5100 rpm 1:5 gears 24p he has a slip of 9.4

I’ve been working with Alexi on my tune, so Sunday, “in glass above sandbar” I ran 106mph at 5600 rpm 1:36 gears 30” B1 (labbed, but only balanced and sharpened) and get the same prop slip.

Now, we all know, I have a whole lot less boat touching the water at this speed.
I’m guessing, my x dimension is higher, thus more slip compared to the drag? I don’t know , it’s all farking majic.

DD is a 27’ Daytona, I’m a 26’ (same bottom on both)
So from what I've researched any prop slip numbers in the single digits is pretty good correct?
 

02HoWaRd26

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So from what I've researched any prop slip numbers in the single digits is pretty good correct?
Yes but i did the math last night as well, and thought it seemed too good to be true. Are your speeds coming from gps? Or water speedometer? I typically see the 11-12% range on mine with 496 as well, but smaller boat.
 

HavaToon

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So from what I've researched any prop slip numbers in the single digits is pretty good correct?
Single digit slip are awesome and hard to achieve.

You said your absolute best speed was 70mph with the 24 at 5100, that’s 9.4% slip. Doable with light load for sure.

I would venture to say with normal load you were more like 65mph with the 24 at call it 5000, that’s 14.19% slip and realistic. 4900 would be 12.43% slip which is still realistic.

Like I said that’s exactly where my magic ran RPM, MPH (gps) and slip. I’d say the 24 is perfect for your boat. But your boat may really like a 5 blade for the additional lift.


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Dirty Daytona

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Single digit slip are awesome and hard to achieve.

You said your absolute best speed was 70mph with the 24 at 5100, that’s 9.4% slip. Doable with light load for sure.

I would venture to say with normal load you were more like 65mph with the 24 at call it 5000, that’s 14.19% slip and realistic. 4900 would be 12.43% slip which is still realistic.

Like I said that’s exactly where my magic ran RPM, MPH (gps) and slip. I’d say the 24 is perfect for your boat. But your boat may really like a 5 blade for the additional lift.


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Yes I was texting with 02Howard and 70 mph was gps speedo and it was the best I ever did. The "usual" top speed is around 67 mph gps at 5000-5100 rpm. A light or full boat doesn't seem to affect the 67 mph.
 

zx14

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Yes but i did the math last night as well, and thought it seemed too good to be true. Are your speeds coming from gps? Or water speedometer? I typically see the 11-12% range on mine with 496 as well, but smaller boat.
I agree, seems too good, but who am I
 

outboardrick

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As I've said before about prop slip....You first need to know exactly what your prop pitch is and unless you have a pitch gauge you are just guessing. Just because a prop is stamped with a pitch number doesn't mean that is exactly what it is. Some props have different pitch blades, some are progressive pitch, and then cup also makes a difference.
 

n2otoofast4u

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Yes but i did the math last night as well, and thought it seemed too good to be true. Are your speeds coming from gps? Or water speedometer? I typically see the 11-12% range on mine with 496 as well, but smaller boat.
We ran my buddies 03 25 Daytona tonight here in Oregon.

Your old 27 Bravo prop, 1.5 ratio, 5k rpm (on the tach. 03 doesn't work with Smart Craft to get better reading), 73.5 mph on the GPS speedo. I ran the ratio and it comes out at 14%. It's not great, but it's not terrible. Not sure where to go from here!
 

02HoWaRd26

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We ran my buddies 03 25 Daytona tonight here in Oregon.

Your old 27 Bravo prop, 1.5 ratio, 5k rpm (on the tach. 03 doesn't work with Smart Craft to get better reading), 73.5 mph on the GPS speedo. I ran the ratio and it comes out at 14%. It's not great, but it's not terrible. Not sure where to go from here!
What motor and drive?
 

02HoWaRd26

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496HO with a stock B1.
Inversion plates removed? That’s a quick easy 8-10hp they say but honestly I’d say i saw a bigger difference between stock and no plates than from stock with no plates to my Dane Headers.
But if he’s pulling that 27p to 5k there’s not much more you can do, maybe look at labbing it but that shouldn’t change the slip very much if at all.
If i recall correctly that prop was worked prior, and say it’s a 26p instead, that brings you to a real decent 10% so if it’s half at 26.5p that’s 12%.
 

hallett21

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Are you getting your speed while running on the lake or the river. Headed down river the gps will read the speed you’re traveling. Including the 5-7mph current


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02HoWaRd26

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Looks like that 22p was plenty torqued this weekend lol
96FED09A-E131-4B86-B878-CA2EBED0F346.jpeg
 

zx14

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Are you getting your speed while running on the lake or the river. Headed down river the gps will read the speed you’re traveling. Including the 5-7mph current

So does your theory work going upstream, you think my 106 up river was really 110?
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hallett21

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Im just commenting on the slip number. If he is indeed getting single digit slip numbers thats great.

For instance in my boat just south of Laughlin i've had the GPS showing 72 mph at 6000 rpm with a 1.75 G/R and a 23p prop. That calculates to 4%.

21 ft non stepped hull with a 250 optimax.

Ive never achieved those numbers on the lake ;)


edit: same numbers as above gets me 65mph any day of the week. But I am at 13% slip
 

zx14

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Im just commenting on the slip number. If he is indeed getting single digit slip numbers thats great.

For instance in my boat just south of Laughlin i've had the GPS showing 72 mph at 6000 rpm with a 1.75 G/R and a 23p prop. That calculates to 4%.

21 ft non stepped hull with a 250 optimax.

Ive never achieved those numbers on the lake ;)


edit: same numbers as above gets me 65mph any day of the week. But I am at 13% slip
Ya, I don’t think 4% is even achievable
 

bocco

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I'm thinking about a prop swap as well. My current prop is a Bravo 1 26p. I have heard that they are not true to the advertised pitch.
Curious that the cutting edge web site doesn't have any pricing info.
 

ONE-A-DAY

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One prop is never the answer, so many variables, temp, load, etc., its a give and take on a prop, something gained means something lost on the other end of the spectrum. Best bet is have a few and change them out based on what you plan on doing for the day. Takes all of two minutes with a electric impact.
 
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