Nmca_chevy

Iv got a 32ft envision. It had 2in shorties and xr drives. 625 EFI motors. The prop slip is 29%. Would putting boxes and raising the drives 2 more inches help? Running 4 blade 28 labs. what are some options. Thank you

AIR TIME

either try 5 blades or 1'' spacers, thats a lot of slip.

jeffswav

Going up higher will raise your slip numbers. Going back without raising should lower your slip numbers. More blades will lower your slip numbers but put more stress on your drive.

Griff

Frequency's old boat?????? I would first try adding a one inch spacer. Boxes may help, but I wouldn't raise the drive height when doing them. Another option is try some 5 blades.

Pretty sure Young Performance set up the boat so you may want to check him.

Nmca_chevy

I was told the slip numbers were so high because the drives were to low in the water. I dont know how all that works exactly so I dont know. But any info would help. It would be a lot easier to go down with the props than to go up.

jeffswav

Somone is giving you wrong info. Lower your drives lowers the slip numbers, raising your drive can increase your slip numbers. The trick is to find the sweet spot, if it is too deep you are loosing speed, too high and you have too much slip and loose speed or cannot plane off. Trial and error, see if somone out there has the same boat, that has found the sweet spot.

How deep are your drives ???

Knot 4 Me

Has to be his old boat.

Frequency

I would agree it has to be my old boat. The propshafts are about 1.5 inches lower than factory, and factory was plenty deep.

Boxes would have been my next modification.

Nmca_chevy

Yes this is your old boat. The propshafts were about 4 inches lower than stock and with the shorties thats right at 2 or 1 1/2 inches lower than stock.

With labbed 28s 4 blades it has terrible prop slip.

Im getting mixed answers. Some people say they are already to low and some people say they are to high.

Can you private message me and tell me the history of the boat. How did it run for you? Thank you

jeffswav

It could be that you are getting your terms mixed up. Some people interchange x-dimension and propshaft depth. The x-dim is the relationship of the bottom of the boat and the crankshft centerline of the engine. The propshaft depth is the measurment of the bottom of the boat to the center of the propshaft.
It sound like your drive is too high causing too much slip. You could get a spacer, try a 5 blade prop or try a standard ext box with no raise.

Before you do anything how deep are they now? If you do not know get a measurment. Before you know this information you are just guessing.