high altitude prop

Does anyone have a good prop for a 2020 sl 450 that would be able to get me up to surf speed full of people and ballast at 6500 ft. Also, does the high altitude prop make the wake worse or does it have no effect? It runs fine now except full of ballast and people. It struggles to get past 10.8 mph.

What prop are you running now?

Supra and ACME props worked on an ideal prop for the 400/450 with the 1.76 transmission. It’s a 16x13.9 ACME 3591 and it’s the prop of choice on the 2021 Supras.

It’s spendy, but you may want to give ACME a call, their tech support is top notch.


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I have a 2019 450 sl and found that at Lake Tahoe, 6200 elevation, I needed something more aggressive also. After talking with JT at Nettles, I went with the ACME 3145 it is 16x13 with the same .105 cup. I lose top end, but we can surf at 11.4 mph with 8 adults and 1,000 lbs of lead

Quote:

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Originally Posted by DDNorCal

I have a 2019 450 sl and found that at Lake Tahoe, 6200 elevation, I needed something more aggressive also. After talking with JT at Nettles, I went with the ACME 3145 it is 16x13 with the same .105 cup. I lose top end, but we can surf at 11.4 mph with 8 adults and 1,000 lbs of lead

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DDNorCal,

What changes do you see when you drop elevation to approx. 4500ft? I ride mostly at Stampede (6000ft), but go to Rollins and Bullards sometimes (3000-3500ft), but i'll have similar lead, and less crew (4-5). I'm curious what the performance changes are and if I should have two different props. I'll probably go with the ACME 3591, and get a second for lower elevation play. We usually start the season east of Tahoe on Lahontan, then move up and over the hill as the season progresses.

This is the first year with this boat so I have some but not a lot of data points. I tend to be at Or near sea level, Delta or Berryessa (before it burned) Or 6000. I find I need a aggressive prop for the high altitudes and prefer the lower rpm’s at lower elevation. With 1k of lead and 8 adults I needed the low end at Berryessa. I’ll give up top end speed for easy surfing and not burning more fuel.

Quote:

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Originally Posted by DDNorCal

This is the first year with this boat so I have some but not a lot of data points. I tend to be at Or near sea level, Delta or Berryessa (before it burned) Or 6000. I find I need a aggressive prop for the high altitudes and prefer the lower rpm’s at lower elevation. With 1k of lead and 8 adults I needed the low end at Berryessa. I’ll give up top end speed for easy surfing and not burning more fuel.

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How much top end speed do you loose?

I started with the 3337 and dropped from 36 to 32. I know use the 3337 as a back up.

Quote:

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Originally Posted by DDNorCal

I started with the 3337 and dropped from 36 to 32. I know use the 3337 as a back up.

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so with the 3145 do you still get a clean wake. The guy at the dealership was telling us that it makes the wake choppy.

I have not noticed a difference.

Just looked a couple of pictures. Clean wave