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  1. #1
    Join Date
    Jun 2010
    Location
    Colorado Springs
    Posts
    113

    Default Prop choice for 575 with 1.70 transmission

    Im curious what prop you guys are running. For 2022 they changed the ratio on the 575 from 1.5-1.70. I ordered mine with the 16x13.9 it’s got tons of power but curious with the new gearing if it will pull the acme 3499 16x17. That is considered the stock propeller. I’d like to run it surfing if possible to drop the rpms down a bit. Anyone tried it?
    2024 SE550
    2022 SL550 (Sold)

  2. #2
    Join Date
    Jun 2020
    Posts
    26

    Default

    I started with the stock 16x13.9x.105 as well but was also wanting lower surf & cruise RPM as well as higher top speed. I'm sometimes at elevation so didn't want to go all the way to 16x17. I did the 3369 (16x15x.120) and was expecting a bigger change than I got. Surf RPMs didn't change much, 25mph cruise RPM only slightly dropped, and I didn't get much more top end because the motor won't max-out with this prop - I have no idea why. It feels like there's plenty of power but it just won't hold a steady RPM above about 5k (about 37mph) and it won't go above about 38mph even though there's RPM left. The motor surges and then backs off almost like it's trying to intermittently control your speed. I was expecting 40mph or more with this prop change. Any ideas on this?

    If you try the 3499 16x17, please let us know your results. What elevation are you at?
    2022 Supra SL550 (current)
    2019 Adonia (75' houseboat at Lake Powell - current)
    2021 Tige Z3 (past)
    2020 SL400 (past)
    Idaho

  3. #3
    Join Date
    May 2018
    Posts
    4,920

    Default

    My understanding is the 16x13.9x.105 was developed by Supra with Acme for the 1.76 trans.

    The 16x13.9 replaced the 16x15, so it makes sense that you don’t see much difference.

    The 575/1.7 should rock a 16x17 all day and twice on Sunday.


    Sent from my iPhone using Tapatalk
    2021 Supra SA 400
    2018 Supra SA 400 (SOLD)
    Michigan

  4. #4
    Join Date
    Jun 2010
    Location
    Colorado Springs
    Posts
    113

    Default

    Quote Originally Posted by mmmkay View Post
    I started with the stock 16x13.9x.105 as well but was also wanting lower surf & cruise RPM as well as higher top speed. I'm sometimes at elevation so didn't want to go all the way to 16x17. I did the 3369 (16x15x.120) and was expecting a bigger change than I got. Surf RPMs didn't change much, 25mph cruise RPM only slightly dropped, and I didn't get much more top end because the motor won't max-out with this prop - I have no idea why. It feels like there's plenty of power but it just won't hold a steady RPM above about 5k (about 37mph) and it won't go above about 38mph even though there's RPM left. The motor surges and then backs off almost like it's trying to intermittently control your speed. I was expecting 40mph or more with this prop change. Any ideas on this?

    If you try the 3499 16x17, please let us know your results. What elevation are you at?

    I also have the 16x15 off of my old sl. I was going to try it but on our older 450 like you said It was almost no difference from the 13.9. I think I’ll go ahead and pick it up and give it a try. We have a lake that we occasionally go to that is 6000’ so I’m sure the 13.9 will be best there. However the one we spend most of the time at is around 2800’ this is where I’m thinking the larger prop will be better.

    I wonder if your upper rpm issues is related to fuel. I know here in Colorado 91 is the max we can get and I believe it prefers 93. If that’s the case it could be knock sensors pulling timing to protect the engine.

    I’m not sure why they changed the ratio on the 550, I wonder if it’s a supply issue and that way all the engine options are the same.
    I’ll order it and let you know.
    Last edited by mjb929rr; 04-20-2022 at 12:42 PM.
    2024 SE550
    2022 SL550 (Sold)

  5. #5
    Join Date
    May 2018
    Posts
    4,920

    Default

    Quote Originally Posted by mjb929rr View Post
    I also have the 16x15 off of my old sl. I was going to try it but on our older 450 like you said It was almost no difference from the 13.9. I think I’ll go ahead and pick it up and give it a try. We have a lake that we occasionally go to that is 6000’ so I’m sure the 13.9 will be best there. However the one we spend most of the time at is around 2800’ this is where I’m thinking the larger prop will be better.

    I wonder if your upper rpm issues is related to fuel. I know here in Colorado 91 is the max we can get and I believe it prefers 93. If that’s the case it could be knock sensors pulling timing to protect the engine.

    I’m not sure why they changed the ratio on the 550, I wonder if it’s a supply issue and that way all the engine options are the same.
    I’ll order it and let you know.
    Tige runs the 2:1 on the 575 and run 16.5” and 17” props.

    The lower gearing works.


    Sent from my iPhone using Tapatalk
    2021 Supra SA 400
    2018 Supra SA 400 (SOLD)
    Michigan

  6. #6
    Join Date
    Nov 2016
    Location
    Knoxville, TN
    Posts
    1,372

    Default

    I ran the ACME 16x13.9 and OJ 16x15 back to back on our 400 (yes my 18 has the 1.70 ratio) and saw good results. The 13.9 is lower rpm surfing, but the 15 is better at wakeboard speeds which we do way more and better empty cruising. With the 550, you should easily be able to run the 16x17 or 16x18. call Eric at OJ and talk to him, his knowledge and customer service is second to none.
    2018 Supra SA400 aka The Ron Burgandy
    2011 Sea-Doo Wake 155
    2015 Mojo Surf, sold...2013 Axis A22 Recon Edition, sold...2010 Axis A22, sold...2007 Maxum 1800sr3, sold

  7. #7
    Join Date
    Jun 2010
    Location
    Colorado Springs
    Posts
    113

    Default

    I just wanted to update this thread. I did go ahead and purchase the acme 3499 16x17. We were able to run it Friday at Pueblo which is 5000’ elevation. Surfing Rpms still 37-3800. Boat had a much harder time maintaining consistent pitch. Overall I see no benefit in this prop at all. I think surfing creates a lot of prop slip, therefore the rpms arent relevant like they would be when changing gear ratios in a car.

  8. #8
    Join Date
    Mar 2021
    Location
    South Georgia
    Posts
    1,953

    Default

    This is what I was running this past Saturday. It was windy as all get out and hard to be consistent. But I have a Makai 400 with a 15x15.5 OJ on it. Full stock ballast (4,000 lb total) and 7 average size people on the boat. Wave was really good with a lot of push. My son actually completed and saved his first 360 on a Shim just before this photo. Unfortunately nobody was videoing. Wife snapped this picture of my son surfing a Ride later. Easy board.

    Sent from my SM-G781V using Tapatalk
    2021 Moomba Makai
    Black Cherry Metal Flake & Fire Red
    Nibral OJ 15.5x15 Altitude/Wake prop w/1.76 trans v-drive
    Wet Sounds bow speakers & 10's on the Tower & ported sub

  9. #9
    Join Date
    Jun 2020
    Posts
    26

    Default

    Quote Originally Posted by mjb929rr View Post
    I just wanted to update this thread. I did go ahead and purchase the acme 3499 16x17. We were able to run it Friday at Pueblo which is 5000’ elevation. Surfing Rpms still 37-3800. Boat had a much harder time maintaining consistent pitch. Overall I see no benefit in this prop at all. I think surfing creates a lot of prop slip, therefore the rpms arent relevant like they would be when changing gear ratios in a car.
    Very interesting that surf RPMs didn't change much with such a big change in pitch. Did you test the top speed? Any issues maxing out?
    2022 Supra SL550 (current)
    2019 Adonia (75' houseboat at Lake Powell - current)
    2021 Tige Z3 (past)
    2020 SL400 (past)
    Idaho

  10. #10
    Join Date
    Jun 2010
    Location
    Colorado Springs
    Posts
    113

    Default

    I never went above 25 mph. Even for a couple mph on top it wouldn’t be worth it. With 4 people in the boat, 1000lbs lead and all ballast full I had to move a couple people up front to get to our 11.6 target speed. I think the prop has a ton of slip when loaded up for surfing. It reminded me of our former sl450 loaded down with the 13.9” prop
    2024 SE550
    2022 SL550 (Sold)

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