There is a give and take relationship between torque and top end; you cannot have both. If you a higher torque prop you will have to sacrifice top end, which sounds like what you want. I would go 4-blade; the lower the pitch the better torque. A 16 pitch prop is a good compromise between torque and speed. Work with your dealer to ensure the prop will work with the gearing ratio in the Supra 21V (you probably have a 1.5-1 ratio as opposed to a 1-1 as typical in a direct drive). Find out what the Supra Tournament Boats are using; they might be down in the 14 to 15 pitch range and may increase diameter to 14 or 14.5, check it out. I hope this helps a bit. I have a VLX and just bought the stock 4-blade prop (16P); the current stock prop is a 17.5P, I opted for the lower torque prop that was stock for my year boat. My rationalization was that the manufacturers spend a lot of time and $$$ to find the best prop for all occasions and some top end was desired and did play into my decision. During my prop hunt, I did learn that some tourney VLXs are running a 14.5x14.25 prop, this is a full inch larger than the stock prop. Spoke with one guy, he loved the larger diameter, lower pitch prop and said he would not be going back. Again work with your Supra dealer and try calling the dealers that provide the tourney boats for the events in your area to see what they use for their setup.
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