B3 with 4/3 blades . Vs 3/3 blades

[Cobaltschus]

Got back into boating, My old boat was a 20’ Crownline with 350mag on a 3/3 blade B3 set up (60+mph)

My new (to me) boat is a bit of a special. 2016 R5 with 520 B3XR drive. However the props are 4 blade/3 blade (26P)
Have read that merc uses the 4 blade to help lower HP boats plain quicker.

Being this is a 520 wouldn’t the 3/3 blade set up a better option? (Comparable Volvo DP are 3/3 blades).

Know cobalt is a heavy boat, however during wet test was only seeing ~62mph on gps

Is it me or did mercury racing miss out on this set up?

If so what 3/3 prop set up should one be looking at?

[Big Block Power]

Got back into boating, My old boat was a 20’ Crownline with 350mag on a 3/3 blade B3 set up (60+mph)

My new (to me) boat is a bit of a special. 2016 R5 with 520 B3XR drive. However the props are 4 blade/3 blade (26P)
Have read that merc uses the 4 blade to help lower HP boats plain quicker.

Being this is a 520 wouldn’t the 3/3 blade set up a better option? (Comparable Volvo DP are 3/3 blades).

Know cobalt is a heavy boat, however during wet test was only seeing ~62mph on gps

Is it me or did mercury racing miss out on this set up?

If so what 3/3 prop set up should one be looking at?

Mercury wants that for some reason. The big bad thing is Cobalt is not made for speed. Yea you sure would think that it should be a 70mph boat but nope. A 430 gets What mid to high 50s so low to mid 60s with a 520 not surprising. My little 220 with 425+hp has the same speed issue.


https://www.mercuryracing.com/sterndriv ... -xr-drive/

[akorcovelos]

You’ll pick up a nominal amount of top speed with the 3x3. The B3 hits a wall at 60ish mph, at which point you need to throw a LOT of HP at it to get beyond that. I’m honestly surprised a 520 didn’t come paired to a B1 XR, which would give you another few mph up top, but obviously hurt you down low out of the hole.