Drive/Speed Question: Please read
 

I need help from the experts.

I have a 91 Apache 28. I recently installed a pair of 550hp 496's, verified dyno sheets and reputable builder. I could not find the speed I was looking for and finally realized I have 1:36 drives, hmmm (don't ask). Here are the specs. The boats weighs in the 7000+ range. It is currently running 71-72 on GPS at 4800 rpm spinning mirage plus 23's, not labbed. The engines will redline at 6100 with a rev-limiter at 5400rpm's. With these drives, the motors have never been past 4800 rpm's. I want to run in the 5100-5200 rpm range for optimum power. I have tried only larger pitch props and the rpm's die. I really do not want to invest in smaller props at this time, rather use the money toward 1:50 drives.

My question.

If I switch to 1:50 drives, what kind of speed do you think I could/should reach. I have a set of 27 Mirage labs just waiting for thier turn. This is a heavy boat and I do not expect to light up the water. It can handle the roughest water comfortably, but I just expect more SPEED! If you are go to ask what the drag % is, use the highest. I need help.

No way you'll be able spin the 27's fast enough by just switching to 1.5 gears.

Actually, you would most likely spin the 23's at +/-5400 rpms with the 1.5's. That will also depend on your engines and how much hp and what rpm peak torque is at.

I would try/demo some 21's and go from there. Some one may want trade you and it could only be a minimal cost.

sounds like you might want to play with some shortie gear cases and raise the X dimension a couple of inches!sounds like your slippage % isnt high enough!

Max Torque is 570 at 4600rpm.

You are on the right track...
 

Go with the 1.50:1 gears. It will be the best thing to do.
You can mess around with everything else but eventually you will go to the 1.50's and wish you had done it right away!
1.36 gears work well only in a very few boat/engine/prop combos.
Dennis Moore

Guys,

Thanks for the info. I will invest in 1:50's this winter, no cash now.

Too Old. I know the Powerplay you are talking about. It is here on Lanier. New 1:50 drive as well as new engine block.

The platform you sold me works great. I posted a pick, hard to see because of the lighting. Once I cut the exhaust pipes, fit like a glove.

Thanks Mike