Better ride when you go FASTER through small chop?

[SBH2OMan]

So I was coming home from the islands the other day and as we came into the coast, things laid down to a 1-3' chop and no rollers, so I decided top check my WOT performance (since I've been tinkering with TPS and O2 stuff lately). She jumped right to WOT, so I backed down, and in so doing noticed that the ride was NOTICEABLY better at around 28 mph (where I'm turning like 5300 rpms) than at my normal cruise of 20-21 mph (where I'm still turning like 4700 rpm).

I am becoming more convinced than ever that I am woefully underpropped (I came home the other day after burning 78 gallons for 120 mile trip) because in order to cruise at a speed where the ride seems comfortable (around 24+ mph) I have to really rev the engine (4800 to 5000). Its where the hull seems happiest, but the motor sure sucks gas at that speed (like 18 to 20 gph).

Just curious about other people's experience with their 2320's with regard to "most comfortable cruise speed in small chop"...

Thanks,

 

[miky2884]

I run around 4200 and cruise at 25-27mph not sure of my fuel burn at that speed but thats where the boat seems to ride good and im not pushing the engine

 

[DaleH]

Bottom line ... the right prop will have you 200-300 RPMs off maximum revs. Best tested on a clean bottom (painted or not), typical boat gear always carried aboard, you and 1/3rd to 1/2 fuel max.

You didn't mention trim tab use, as those could change your perception at various speeds and conditions.

 

[SBH2OMan]

I was running with "moderate" tabs (maybe 1/3) on stock lencos and it was so smooth I pulled them alll the way up and ran like that just to compare. At that speed (28 mph over ground) they didn't improve the ride (it was great) and didn't seem to make a difference in gph

 

[POGE]

I have experienced that too. I think it is the bow getting down to provide a sharper entry point as the increased throttle pushes the bow down a little. I will try to trim the tabs and motor to get the same ride with a little less drag by having the bow down so much. I have the factory set up and prop 17T and burn just under8.8 to 9 gals per hour at 4100, 27 mph with new bottom paint. At this point in the summer I need to go to about 4300 to get the same with all the funky growth on the boat now.

 

[SBH2OMan]

So I just called Ken at PropGods and chatted for a bit. I gave him my performance numbers and he immediately pointed out that I'm getting about 30% to 50% SLIP with my current prop. :shock:

So not only is it under-propped with a 15, but compounding the problem is the fact that it is slipping BADLY.

I'm now pouring through the other thread about props to see if anyone posted slip numbers for a Quicksilver or Mirage 3-blade. According to Ken I should expect more like 10% slip, which will make a MASSIVE difference in speed and fuel economy, obviously.

 

[Brian S]

So I just called Ken at PropGods and chatted for a bit. I gave him my performance numbers and he immediately pointed out that I'm getting about 30% to 50% SLIP with my current prop. :shock:

So not only is it under-propped with a 15, but compounding the problem is the fact that it is slipping BADLY.

I'm now pouring through the other thread about props to see if anyone posted slip numbers for a Quicksilver or Mirage 3-blade. According to Ken I should expect more like 10% slip, which will make a MASSIVE difference in speed and fuel economy, obviously.

I have a mirage 17p sitting in my garage that I never got around to selling if you need one.

 

[SBH2OMan]

So I just called Ken at PropGods and chatted for a bit. I gave him my performance numbers and he immediately pointed out that I'm getting about 30% to 50% SLIP with my current prop. :shock:

So not only is it under-propped with a 15, but compounding the problem is the fact that it is slipping BADLY.

I'm now pouring through the other thread about props to see if anyone posted slip numbers for a Quicksilver or Mirage 3-blade. According to Ken I should expect more like 10% slip, which will make a MASSIVE difference in speed and fuel economy, obviously.

I have a mirage 17p sitting in my garage that I never got around to selling if you need one.

Definitely interested! I sent you a PM yesterday. Please pm me with details. (does it have the yamaha hub kit with the 2 stroke thrust washer, or was it set up for a different motor? or is there no hub kit? How much do you want for it, etc.).

Thanks!

BTW, I'll be in San Diego next week and might be able to just pick it up from you depending on where you are.

Brent

 

[Brian S]

So I just called Ken at PropGods and chatted for a bit. I gave him my performance numbers and he immediately pointed out that I'm getting about 30% to 50% SLIP with my current prop. :shock:

So not only is it under-propped with a 15, but compounding the problem is the fact that it is slipping BADLY.

I'm now pouring through the other thread about props to see if anyone posted slip numbers for a Quicksilver or Mirage 3-blade. According to Ken I should expect more like 10% slip, which will make a MASSIVE difference in speed and fuel economy, obviously.

I have a mirage 17p sitting in my garage that I never got around to selling if you need one.

Pm sent
Definitely interested! I sent you a PM yesterday. Please pm me with details. (does it have the yamaha hub kit with the 2 stroke thrust washer, or was it set up for a different motor? or is there no hub kit? How much do you want for it, etc.).

Thanks!

BTW, I'll be in San Diego next week and might be able to just pick it up from you depending on where you are.

Brent

 

[jeffnick]

Was there any explanation for the exaggerated slip numbers? Wouldn't one expect minimal slip if underpropped?

 

[SBH2OMan]

Yes, he said that the Powertech props are "inconsistent" and not very deep cupped, which makes them more sensitive to "disturbed water". I have a high-speed fairing block type transducer that is mounted about amidship, just port of the center line by about 8". I'm assuming that this is enough to cause problems for the already sensitive prop. It amazes me that I've been driving this boat for 9 months now with it being so BADLY propped. I guess I've been too busy fixing other issues to have come to the realization that it was so inefficient!

 

[bigk23surf]

So I just called Ken at PropGods and chatted for a bit. I gave him my performance numbers and he immediately pointed out that I'm getting about 30% to 50% SLIP with my current prop. :shock:

So not only is it under-propped with a 15, but compounding the problem is the fact that it is slipping BADLY.

I'm now pouring through the other thread about props to see if anyone posted slip numbers for a Quicksilver or Mirage 3-blade. According to Ken I should expect more like 10% slip, which will make a MASSIVE difference in speed and fuel economy, obviously.

I have a mirage 17p sitting in my garage that I never got around to selling if you need one.

If SBH2OMan does not want it send me a message, I'm looking for one too.