Best prop for a 280 silencer??
07-27-2002, 06:35 AM
#11
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pwrbotr,
When you lab a prop, you get more RPM's out of the same prop; thus easier to spin.
I would try a 24 Hydro not any version (labber or not) of a 26 hydro. The boat does not like Hydros except they are fast props. They are difficult to get on plane w/ a PQ 280. Ask Jon 280 Silencer, he JUST tried a Hydro on his 280 about 3 weeks ago.
When I had my Labbed 24 bravo, I too was at 5000 rpm (actually a bit more) I sent it back to Merc where they added more cup. This did nothing for cruise speed OR top speed, ALL it did was lower my RPMs.
I don't think your gonna get a cruise of 48-52 at approx 3800 rpm with a single engine boat. With all my experience with the boat aand all the different props I've tried, it looks to me like you got the right prop. You're at the right RPM range (5000) at full throttle.
The only way to gain more speed and or lower your cruise RPM is to go higher in pitch. The downside is, the boat will be very slow out of the hole and top speed will suffer. That said, see if you can try a labbed (only a labbed) bravo 28P. You MAY get lucky and get your full throttle RPM with in 4600- 5000 range. If it IS in the lower part of that range at full throttle, you can send the prop back to Merc (or who ever labbed the prop) and see if the can remove some cup to bring your RPM's up. This scenareo will raise your cruise speed to around what your looking for. BUT increasing cup on your labbed 26P will do ZERO for cruise speed / rpm at cruise.
You may want to try a non labbed 26p Bravo. When you Lab a prop, you lose some cruise speed as they have more (I think) slip.
When you lab a prop, you get more RPM's out of the same prop; thus easier to spin.
I would try a 24 Hydro not any version (labber or not) of a 26 hydro. The boat does not like Hydros except they are fast props. They are difficult to get on plane w/ a PQ 280. Ask Jon 280 Silencer, he JUST tried a Hydro on his 280 about 3 weeks ago.
When I had my Labbed 24 bravo, I too was at 5000 rpm (actually a bit more) I sent it back to Merc where they added more cup. This did nothing for cruise speed OR top speed, ALL it did was lower my RPMs.
I don't think your gonna get a cruise of 48-52 at approx 3800 rpm with a single engine boat. With all my experience with the boat aand all the different props I've tried, it looks to me like you got the right prop. You're at the right RPM range (5000) at full throttle.
The only way to gain more speed and or lower your cruise RPM is to go higher in pitch. The downside is, the boat will be very slow out of the hole and top speed will suffer. That said, see if you can try a labbed (only a labbed) bravo 28P. You MAY get lucky and get your full throttle RPM with in 4600- 5000 range. If it IS in the lower part of that range at full throttle, you can send the prop back to Merc (or who ever labbed the prop) and see if the can remove some cup to bring your RPM's up. This scenareo will raise your cruise speed to around what your looking for. BUT increasing cup on your labbed 26P will do ZERO for cruise speed / rpm at cruise.
You may want to try a non labbed 26p Bravo. When you Lab a prop, you lose some cruise speed as they have more (I think) slip.
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08-13-2002, 01:58 PM
#12
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BILLR
BillR
Bill, I have tried several variations of you recommendations:
stock 24 bravo: spinning 5100 before trim, tripping rev limiter at apprx 5300, running roughly 66gps. Heavy chop and poor cruise speed. 3500 @36 mph 4000 @ 44
stock 25 hydro: spinning 5100, poor cruise, not much better than above, about the same top end.
This weekend I will be in Destin and look to borrow a stock 26 bravo from a buddy. I hope this will work. Not sure what else to try. Based on your numbers, I am spinning my prop much faster but same speeds. The 24 labbed bravo over revs the motor. I did noticve that the boat has a perfect hook on the leading edge 6 inches from the transom. I called mark at PQ and he says it needs to be there. I can't figure out what the hecks wrong with my ride. I think I need more bow lift as I have a lot of spray at cruise speed.
Bill, I have tried several variations of you recommendations:
stock 24 bravo: spinning 5100 before trim, tripping rev limiter at apprx 5300, running roughly 66gps. Heavy chop and poor cruise speed. 3500 @36 mph 4000 @ 44
stock 25 hydro: spinning 5100, poor cruise, not much better than above, about the same top end.
This weekend I will be in Destin and look to borrow a stock 26 bravo from a buddy. I hope this will work. Not sure what else to try. Based on your numbers, I am spinning my prop much faster but same speeds. The 24 labbed bravo over revs the motor. I did noticve that the boat has a perfect hook on the leading edge 6 inches from the transom. I called mark at PQ and he says it needs to be there. I can't figure out what the hecks wrong with my ride. I think I need more bow lift as I have a lot of spray at cruise speed.
08-13-2002, 02:11 PM
#13
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Your numbers sound about right on!
My boat was pretty heavy as I had a lot of options. On that Bravo 26P; it should be a labbed version, otherwise I don't think you'll get much more improvement.
Just a thought, how much are you trimming up? I got best top speed trimmed just SLIGHTLY above 1/4 up on the gauge. More trim than that and the boat RPMS would increase while speed would drop.
My boat was pretty heavy as I had a lot of options. On that Bravo 26P; it should be a labbed version, otherwise I don't think you'll get much more improvement.
Just a thought, how much are you trimming up? I got best top speed trimmed just SLIGHTLY above 1/4 up on the gauge. More trim than that and the boat RPMS would increase while speed would drop.
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08-13-2002, 03:03 PM
#14
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BillR,
I agree with the trim about 1/4. The boat like more trim at higher speeds but 1/4 is optimum at cruise.
So you think that this is the best I will see for cruise speeds? I've got to be able to improve just a bit...if not I have a 2001 PQ for sale!!
I agree with the trim about 1/4. The boat like more trim at higher speeds but 1/4 is optimum at cruise.
So you think that this is the best I will see for cruise speeds? I've got to be able to improve just a bit...if not I have a 2001 PQ for sale!!
08-13-2002, 04:50 PM
#15
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Well, I don't know of ANY single engine 28ish foot boat that will cruise 50 MPH at 3500 to 3800 RPM. That type of cruise speed/rpm is twinn engine speeds.
The 26P will net you a few MPH more but not 10-15 Cruise MPH.
A Hydromotive will increase cruise speed somewhat too.
If you want to sell, OSO member Mattt is looking for a PQ.
If that 26P DOES work for ya, Jon 280 Silencer is lookin for a 26P lab prop.
The 26P will net you a few MPH more but not 10-15 Cruise MPH.
A Hydromotive will increase cruise speed somewhat too.
If you want to sell, OSO member Mattt is looking for a PQ.
If that 26P DOES work for ya, Jon 280 Silencer is lookin for a 26P lab prop.
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08-19-2002, 05:27 PM
#16
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I have a labbed 28 B1 for sale. It has 25 hours on it and is in new condition. Prop was done @ Hall's propeller service in Christmas, Florida. Mike Markesteyn is the owner and does alot of work with APBA teams. When he got done with my prop it looks alot like a Hydro but performs light years better than the Hydro I had. When I re-powered this year I was spinning a 24 Hydro 5400+. This prop put me right at 5100. Comes out of the hole like a rocket compared to the 24 Hydro and gives a better top speed than a 26 Hydro.
08-19-2002, 09:41 PM
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What type of boat was this tested on? Powerquest 280? What type of repower? I want to make sure that we are comparing apples to apples. Do you have a number for the prop shop you used? Any help with the above would be great!
08-19-2002, 11:43 PM
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I have a Velocity 280. It had a 365 HP 454 Mag and spun a 24 Hydro @ 47-4800. I repowered with a 485 HP 502 and could spin the 24 hydro 5400+(I stopped). I ordered the 28 lab finished B1 as everyone told me the 26 Hydro and 28 B1 were comparable and I didn't like the Hydro I had. All I can say is I am impressed. Looking at your posts I'm sure this prop will be close. If not, Mike can work it a little to get your desired RPM's. Give him a call @ 407-568-5506. BTW, I can spin this 28 51-5200 with a full load of fuel and 4 passengers. For your application I would suspect the RPM to be around 4800-4900 with much better cruise and top end.
08-20-2002, 11:23 AM
#19
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"stock 24 bravo: spinning 5100 before trim, tripping rev limiter at apprx 5300, running roughly 66gps. Heavy chop and poor cruise speed. 3500 @36 mph 4000 @ 44"
Just for comparative purposes with similar sized/configured boats...
BillR's numbers are with the 502mag, so your specs will be a little different with the stronger motor.
Pwrbotr, if you were in "heavy chop" you probably had trim "in" and possibly some tab, so your speeds at those rpm would be normal. My numbers are 48-50 at 4000rpm on flat water 39-41 at 3500. With my 28'8" and trimmed down for the real crappy stuff (drive/tabs) I'm at 43-45mph at 4000rpm. My top speeds on good water, depending on load, are consistently 67.5 to 68.7 with 69.2 being the max recorded (all GPS handheld #'s) in perfect conditions.
Pwrbotr, this is with a 496HO turning an out of the box 24p B-1 that could probably use some tuning and has been dinged a little since new. My max rpm is just kissing the 5100 mark....
Just for comparative purposes with similar sized/configured boats...
BillR's numbers are with the 502mag, so your specs will be a little different with the stronger motor.
Pwrbotr, if you were in "heavy chop" you probably had trim "in" and possibly some tab, so your speeds at those rpm would be normal. My numbers are 48-50 at 4000rpm on flat water 39-41 at 3500. With my 28'8" and trimmed down for the real crappy stuff (drive/tabs) I'm at 43-45mph at 4000rpm. My top speeds on good water, depending on load, are consistently 67.5 to 68.7 with 69.2 being the max recorded (all GPS handheld #'s) in perfect conditions.
Pwrbotr, this is with a 496HO turning an out of the box 24p B-1 that could probably use some tuning and has been dinged a little since new. My max rpm is just kissing the 5100 mark....
Last edited by Reckless32; 08-21-2002 at 02:17 AM.
08-20-2002, 08:38 PM
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reckless...i can accept the top end but i have a real problem with my poor cruise speed at 3500 and 4000. the articles in powerboat mag state that this boat is 45mph at 3500 and 55 at 4000 with a 502 mag, i would suspect that my number should be comparable. every person that has ridden on my boat has made the same comment about the poor and unacceptable cruise speed. it feels as if the boat is working hard at 4000 to keep the boat barely at 40 or so. also, it feels as if the bow is not lifting no matter how much trim is applied. i trim until the gps drops. it seems that this hull has tremendous slip at cruise. maybe this is just an inefficient hull...i'd be ecstatic with the numbers the magazine article states.
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