1.88:1 tranny for a 454???

Gregg, Here's my opinion. I feel that you would be getting into a big area of unknowns because a prop change would be needed. I'm sure you have read many of the threads regarding props and the "experimenting" or testing that many go through. Some prop changes work on some boats and others don't. You can talk to to prop manufacturers and they can run the calculations but the bottom line is they will tell you to try a prop change but really don't know exactly what will happen. With the 1.88, you would need to increase the prop pitch and or the prop diameter to compensate for the lower RPM. Increasing prop diameter is tough because to get any room under the boat to swing it a taller strut would be needed and this would increase the shaft angle. This would drastically change the hulls performance and I feel for the worse. Increasing the pitch to a point needed I feel you would be getting into the higher pitches where the efficiency of a prop drops off dramaticly. Efficiency or lack of slip is calculated by testing a boat with GPS speed, the prop RPM and the pitch of the prop.

The 1.88 is made for large boats that swing large props. I don't feel it is a good idea.

ski boats rely on a fast prop speed to shoot them out of the hole, its like the tires on a drag car, they want these props to hook up, as these guy's said if your turning your engine at 1880 rpms (with a 1.88) you will only get a prop speed of 1000 rpms, good for props with mass to move more weight and push a boat up on plane. with a 1.88 you would be way past the torque curve and the boat would propbably top out in the 20's

I agree you can get it up to speed with the right prop, question is whether that prop exists and if it is worth the effort and expense. I would say that he would realistically need a prop in the neighborhood of 13.5 x 23-25. Thats not going to happen in a once inch shaft for sure.

TRBenj wrote: and the Mastercraft Powerslot boats (both 1.26:1 and 1.5:1) to prove that.

Tim, I'm curious as to the prop Dia. and pitch the powerslots run. Do you know?

Yep acme and oj carry the LH 1 1/8" props 13.7 x 17 up to 13.7x19.5 or so for non splined powerslot applications.

I feel that getting more than 1.5:1 in a ski boat it's just too much.

A well propped 1.23:1 is noticeable better out of the hole than a 1:1 and places the engine better in the torque curve.

I remember my friend's '95 SN with the Gt40 Pro Boss, Power Plus tranny and OJ 4 blade prop as one of the best/strongest boats I have ever driven.