Prop setup

[501nmc]

I know this topic gets beat to death but every boat is different and I have searched most of the forums looking for answers and am now somewhat confused. I have a triton tr 17 with a v4 115 yamaha 99 model. I have a 21 pitch semi-cleaver prop (5500-5900 rpm WOT), a yamaha pro series 22 pitch (5250 rpm trimmed all the way up, rooster tail 1' above motor and chine walking), a tempest plus prop 23 pitch (4900 rpm WOT, terrible hole shot but superb handling). My cav plate is 1 1/2'' above keel. I have a stepped transom (2 inches). The 21 pitch performs the best but with full trim, will run 5900 rpm, puts a rooster tail as high as the motor but doesn't hold the water in the turns very well. It usually revs about 200 rpm's higher. As you trim up, you can feel the boat lift at 4000 rpms and again at 5500 rpms. You can feel less drag as you go above 5500 rpms. The water line will move back about 3 inches once you go above 5500 rpms. I do not have gps for the rpms. Speedo reeds 53 at 5500 rpms and goes up to 56 at 5900 rpms on a long run. I like this prop, I just wish it would hold the water better. The 22 pitch prop will run 57 on the speedo but you just can't stay in it because of the chine walk. It holds better in the turns but not what I would expect from a cupped prop. The 23 pitch 4 blade tempest holds the water like a champ. I would like this prop in the 20 pitch but they don't make it. I like the performance of this prop accept for the hole shot and WOT Rpms. I have used the Mercury prop calc and tried several of the settings. They all calculate my rpms to be 5250 at best and suggest some of the props that I already have. I want WOT rpms to be 5500 at full trim and hold fairly well in the corners. I am running the third hole up on the transom. I do not want to purchase a jack plate (just haven't had any luck with them.) Any suggestions on what prop to use? I can go up one more hole with the motor. It will put me 3/4'' higher. I will mention that the center of the prop shaft is 5'' below the transom. Any help would be appreciated.

 

[501nmc]

Correction: The center of the prop shaft is 5'' below the pad not transom.

 

[jestor68]

I didn't know there was a 4 blade Tempest Plus.

 

[501nmc]

Trophy plus. Like I said... I've gotten confused. Lol

 

[Texasmark]

I'd say you got some very good comparative data. Interesting the variations in performance of the different prop designs, course that's why you have so many designs. Don't see a problem with your height since you have a stepped/setback pad. The 21 semi-cleaver, is it a Ballistic? Sounds like mine which has a nice rake and you apparently have a nice rake in this prop as you realized the bow lifting effects as your speed and trim increased, which is what they are designed to do.....get the hull out of the water, especially on padded boats.

Sounds like all you need it to have a prop shop put another inch of pitch in that 21. On blowout in corners, expect that with what you said about straight away WOT performance. I do tight turns and in them I drop the trim slightly and cut the throttle back a thousand which solves the blowout problem; about 2/3 through the turn I hammer down on the throttle and run the trim back out, holds tight.....great sport.

My 2c,
Mark

 

[501nmc]

Thanks for the reply. I did some GPS figures this week. With the 21 pitch at 5800 ROMs, I'm running 54 mph. That equates to 7% slip. I'm not sure who the manufacturer is, it just has 21 stamped on it. I was thinking of just staying with that style for my fishing and getting a 19 pitch aluminum for pulling the kids tubing. I've been around boats my whole life. I've only owned two: an 04 express that was nice but didn't handle rough water an this triton. My dream boat is a skeeter but this one was affordable. Lol. I've driven fiberglass hulls before and they are all different, just the nature of the beast. I like to get everything setup where anyone can drive it, should I try to sell it. Don't want to screw the next guy or anyone who may b on the lake with him.