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Author Topic:   Mirage Plus or Yamaha SWS prop pitch

RJG posted 03-10-2005 07:00 PM ET (US)
I have a 1988 22 Revenge WT WD with a 225 Excell Yamaha. My prop is a 15 1/4 X 15 yamaha stainless painted. At WOT engine turns 5800 RPM up to mid trim. At that point prop begins to blow out and RPMs increase well into the 6000s. 6175 and climbing when I pulled the throttle back. I have read all the posts and feel that the Mirage Plus or SWS would be my best choice. Price would be the determining factor. My question is should I stay with the 15 pitch or move up to the 17. My gear ratio is 1.80. I also have the 129 gallon fuel tank. Bob
Peter posted 03-10-2005 07:53 PM ET (US)
Can you give some data on your speed at WOT?
macfam posted 03-10-2005 08:01 PM ET (US)
RJG,
Have you read jimh's Reference Section on a similar setup?
The only difference is a Yahmaha vs an Evinrude.
See:
Reference: Propeller Tests—eight propellers, Whaler Drive single engine
RJG posted 03-10-2005 08:21 PM ET (US)
Peter
Top speed was 41MPH +-. I was watching my tachometer closer than my GPS.
Macfam
I did read Jims report. There was some feeling on his part that the true pitch of the Mirage may be greater than 15in. Also not all engines are the same. That is why I mentioned the gear ratio though it is just one of many variables. Bob
Peter posted 03-10-2005 10:04 PM ET (US)
I used to have a 22 Revenge notched transom that was pushed by a 3.1L Yamaha 225 turning a 17P SWS propeller to about 43-44 MPH at WOT. You've got a smaller displacement motor and more boat so a 15P in either the SWS or Mirage form should be a good propeller for that boat/motor combination.
RJG posted 03-11-2005 09:07 AM ET (US)
I have been leaning toward the 15in. Prop. Would the 15in. pitch provide as good a bite at full trim as the 17? What helps prevent blow out? Pitch or rake? My primary interest is cruising efficiency but in the event that a sudden summer squall was to pick up I could get out in a hurry.
Peter posted 03-11-2005 10:43 AM ET (US)
Rake helps with propeller blow out. The SWS has a higher rake than the propeller you are using. The SWS is noted for being a good cruising propeller. I think the Mirage is designed a little bit more for speed than cruising efficiency although it seems to cruise reasonably well based on my experience.
RJG posted 03-11-2005 11:18 AM ET (US)
Thank You Peter. Your thoughts varify my own. Taking into consideration the small displacement of my Yamaha, I will go with the SWS 15 1/4 X 15. Though the Mirage is a worthy choice, I checked the clearance between the tip of the blade of my existing prop and the bottom of the cavitation plate and I have about a 1/4in. The 15 1/2in. diameter Mirage would put me too close. I should have looked at that earlier. Bob
RJG posted 03-11-2005 03:24 PM ET (US)
Ordered new prop today. Can't wait until Tuesday.
Macfam
I saw a picture of your boat on another thread. It is very nice:) Wish I had one of those 250's on the back of my boat. Bob
macfam posted 03-11-2005 03:54 PM ET (US)
RJG,
Thanks.
For a single engine, that OX66 Yamaha continues to astonish me with its brute power.
In today's standards, probably not the most fuel efficient, quiet, environmentally friendly etc.
But still one great engine.
jimh posted 03-12-2005 10:34 AM ET (US)
My feeling is that with a REVENGE 22 WT WD and a single engine, the propeller has to have good holding properties. This is because of the design of the Whaler Drive, originally intended primarily for twin engines. The flat-bottom of the Whaler Drive provides a single engine with a relatively high mounting height, so the propeller is subject to blowing out when trimmed out, as RJG noted.
The MIRAGE PLUS propeller seems to have good holding, and the blade seems to be optimized for cruising speeds of 25-30 MPH. At those speeds it produced very efficient performance.
ASIDE: In the recent Verado/E-TEC/Yamaha-F shoot out, the Verado had the MIRAGE PLUS propeller and showed very strong and very fuel efficient performance at 25-30 MPH. It was this performance that earned the Verado much of its praise. The E-TEC has a highly raked propeller (VIPER) that came on strong at high speed, but generally was not efficient at all at 25-30 MPH. This was exactly the same characteristics I noticed when I test the MIRAGE PLUS and the VIPER on my Whaler.
I think that 15-inch is probably the right pitch. In general, I think it is better to have a propeller that allows the engine to reach the very top of its RPM range. Boats tend to gain weight.
The problem with the MIRAGE PLUS in the 15-inch pitch is its large diameter. It was practically an interference fit in the propeller aperture of the Evinrude lower unit.
This spring, I will test the MIRAGE PLUS in 17-inch pitch, but I fear this may be too much propeller.
I will be very interested to hear of the results of the 15-inch pitch on RJG's boat; please keep us informed.
Peter posted 03-12-2005 01:53 PM ET (US)
Jim, your observations regarding the Mirage and Viper are exactly the same as mine, but in a twin installation. The Viper comes on strong at high engine speeds. The Mirage does well at moderate speeds in the 30 MPH range. Unfortunately, on my boat, under about 25 MPH where the boat's attitude starts to rise, the Mirages don't hold terribly well.
Late last year I ran some Rev 4s. These seem to keep the stern lifted more than the Mirages. They clearly hold a slow speed plane very well but are not as fast or as efficient as the Mirages at cruise. I'll probably start out this year running with the Rev 4s but I'm not yet convinced they are the ideal propeller for my situation.
It's too bad that I can't run Yamaha propellers on my boat because I would like to compare the SWS to the Mirage. The SWS I had on my 22 Revenge had a very good hold on the water at all speeds.

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Author	Topic: Mirage Plus or Yamaha SWS prop pitch
RJG	posted 03-10-2005 07:00 PM ET (US) I have a 1988 22 Revenge WT WD with a 225 Excell Yamaha. My prop is a 15 1/4 X 15 yamaha stainless painted. At WOT engine turns 5800 RPM up to mid trim. At that point prop begins to blow out and RPMs increase well into the 6000s. 6175 and climbing when I pulled the throttle back. I have read all the posts and feel that the Mirage Plus or SWS would be my best choice. Price would be the determining factor. My question is should I stay with the 15 pitch or move up to the 17. My gear ratio is 1.80. I also have the 129 gallon fuel tank. Bob
Peter	posted 03-10-2005 07:53 PM ET (US) Can you give some data on your speed at WOT?
macfam	posted 03-10-2005 08:01 PM ET (US) RJG, Have you read jimh's Reference Section on a similar setup? The only difference is a Yahmaha vs an Evinrude. See: Reference: Propeller Tests—eight propellers, Whaler Drive single engine
RJG	posted 03-10-2005 08:21 PM ET (US) Peter Top speed was 41MPH +-. I was watching my tachometer closer than my GPS. Macfam I did read Jims report. There was some feeling on his part that the true pitch of the Mirage may be greater than 15in. Also not all engines are the same. That is why I mentioned the gear ratio though it is just one of many variables. Bob
Peter	posted 03-10-2005 10:04 PM ET (US) I used to have a 22 Revenge notched transom that was pushed by a 3.1L Yamaha 225 turning a 17P SWS propeller to about 43-44 MPH at WOT. You've got a smaller displacement motor and more boat so a 15P in either the SWS or Mirage form should be a good propeller for that boat/motor combination.
RJG	posted 03-11-2005 09:07 AM ET (US) I have been leaning toward the 15in. Prop. Would the 15in. pitch provide as good a bite at full trim as the 17? What helps prevent blow out? Pitch or rake? My primary interest is cruising efficiency but in the event that a sudden summer squall was to pick up I could get out in a hurry.
Peter	posted 03-11-2005 10:43 AM ET (US) Rake helps with propeller blow out. The SWS has a higher rake than the propeller you are using. The SWS is noted for being a good cruising propeller. I think the Mirage is designed a little bit more for speed than cruising efficiency although it seems to cruise reasonably well based on my experience.
RJG	posted 03-11-2005 11:18 AM ET (US) Thank You Peter. Your thoughts varify my own. Taking into consideration the small displacement of my Yamaha, I will go with the SWS 15 1/4 X 15. Though the Mirage is a worthy choice, I checked the clearance between the tip of the blade of my existing prop and the bottom of the cavitation plate and I have about a 1/4in. The 15 1/2in. diameter Mirage would put me too close. I should have looked at that earlier. Bob
RJG	posted 03-11-2005 03:24 PM ET (US) Ordered new prop today. Can't wait until Tuesday. Macfam I saw a picture of your boat on another thread. It is very nice:) Wish I had one of those 250's on the back of my boat. Bob
macfam	posted 03-11-2005 03:54 PM ET (US) RJG, Thanks. For a single engine, that OX66 Yamaha continues to astonish me with its brute power. In today's standards, probably not the most fuel efficient, quiet, environmentally friendly etc. But still one great engine.
jimh	posted 03-12-2005 10:34 AM ET (US) My feeling is that with a REVENGE 22 WT WD and a single engine, the propeller has to have good holding properties. This is because of the design of the Whaler Drive, originally intended primarily for twin engines. The flat-bottom of the Whaler Drive provides a single engine with a relatively high mounting height, so the propeller is subject to blowing out when trimmed out, as RJG noted. The MIRAGE PLUS propeller seems to have good holding, and the blade seems to be optimized for cruising speeds of 25-30 MPH. At those speeds it produced very efficient performance. ASIDE: In the recent Verado/E-TEC/Yamaha-F shoot out, the Verado had the MIRAGE PLUS propeller and showed very strong and very fuel efficient performance at 25-30 MPH. It was this performance that earned the Verado much of its praise. The E-TEC has a highly raked propeller (VIPER) that came on strong at high speed, but generally was not efficient at all at 25-30 MPH. This was exactly the same characteristics I noticed when I test the MIRAGE PLUS and the VIPER on my Whaler. I think that 15-inch is probably the right pitch. In general, I think it is better to have a propeller that allows the engine to reach the very top of its RPM range. Boats tend to gain weight. The problem with the MIRAGE PLUS in the 15-inch pitch is its large diameter. It was practically an interference fit in the propeller aperture of the Evinrude lower unit. This spring, I will test the MIRAGE PLUS in 17-inch pitch, but I fear this may be too much propeller. I will be very interested to hear of the results of the 15-inch pitch on RJG's boat; please keep us informed.
Peter	posted 03-12-2005 01:53 PM ET (US) Jim, your observations regarding the Mirage and Viper are exactly the same as mine, but in a twin installation. The Viper comes on strong at high engine speeds. The Mirage does well at moderate speeds in the 30 MPH range. Unfortunately, on my boat, under about 25 MPH where the boat's attitude starts to rise, the Mirages don't hold terribly well. Late last year I ran some Rev 4s. These seem to keep the stern lifted more than the Mirages. They clearly hold a slow speed plane very well but are not as fast or as efficient as the Mirages at cruise. I'll probably start out this year running with the Rev 4s but I'm not yet convinced they are the ideal propeller for my situation. It's too bad that I can't run Yamaha propellers on my boat because I would like to compare the SWS to the Mirage. The SWS I had on my 22 Revenge had a very good hold on the water at all speeds.