2003 35 Ex prop help
 

I did a search to try to find out what prop works best on a 03 35 ex with 496's and came up blank, the prop calculator show me @ 26% prop slip on 32" 4 blade bravos, seems kinda high any suggestions ? Thanks Blake Sullivan

What gear ratio do you have?

1.5

I think your wrong on the ratio.... You should be a 1.65 and the boat would have came stock with 30 pitch bravo 1's. This is exactly how my friends boat was set up from fountain. 2003 35EX with 496 mag HO's. His ran 77everyday in fresh water with that setup.

Its stamped 1.5 so either its stamped wrong or your freinds came from up north

Most of the 496 equipped boats came with 1.65 ratio B1X drives. Not saying all of them did, but .... They did that so they could use more common pitch props and to allow the engines to get in their sweet spots a little easier.

If it is a 1.5 drive, the 32P is way too much prop for that engine/boat combo. A 35 Lightning Classic with 500's only ran 30P or maybe labbed 32's with a 1.5 drive. Did your boat possibly have different (higher hp) engines in it before you bought it?

Thanks for all the input I was the second owner with 89 hours on it so I dont believe it had big HP motors, but I am @ 78 mph and hitting the rev limiters so I think It must be in its sweet spot . Maybe I should being suck a sissy and but some Big HP motors. :evilb:

78 is right in the average range for that boat/engine combo. Do you know if the props had been reworked or possibly had the diameter cut back some? That could explain being marked 32P with 1.5 ratio and running 78 mph. Our twin step 35 Lightning with 500 EFI's ran labbed 30P Bravo 1's props through 1.5 ratio Bravo XZ drives, but it was right at 86-87 mph (gps on a lake at ~600 ft elevation) on the rev limiters. :D

Wow those are awesome numbers, Im going to try some lab 32 hydro 5 blades tomorrow , Ill report back thanks again for the help

small world I am going to try some 32 pitch 5 blade hydros tomorrow too:lolhit:

I think you are on to someting here. 32's on a 1.5 would be way to much unless they were cut down IMO.

How does the boat accelrate with the 1.65s vs the 1.50?

I stand Corrected my Donzi has 1.5 the fountain does have 1.65 I apologize for my ignorance , but even with 1.65 my prop slip is @ 18 percent which still seems a little high?

Understandable. Per the performance report on my friends, it ran just a tick better with the five blades.

My 46 Black Thunder with five blades ran 18% slip, look at the comparable boats with same or similar power and check their top speed, gear ratio, prop pitch and i think you will find your boat is about on for being factory. The gentleman from the Fountain factory are no slouches IMO. :coolcowboy:

A lot of times you can compensate for too much prop by trimming the drives further out. That will make your slip percentage go up, increase your rpms, but it usually hurts your top speed. What number are you setting for trim at WOT? Also, need to know what number is neutral trim (drive level with boat bottom). With the higher X dimensions Fountain runs, you shouldn't need as much trim. One of the benefits of higher X is that it puts more of the thrust in straight line with the hull with a flatter running boat. Just a thought ...

Plenty of Good Advice
 

Do you have your performance report?

I am not sure where you keep the boat but if you are close you can bring the boat to us and we can work with you to dial it in.

We will also be happy to share a few high performance driving tips along the way.