Awesome. Just...awesome. Great learning here. Perhaps one day I'll have the ability to replicate this set-up.

Outstanding Chris!!!

Nice family cruiser :evilb:

You are finding exactly what we did with the 5 blades. After 93 they are a complete handful. Although our low elevation testing was limited, we did find that the four blades run like they are on rails above that.
Probably a great move with the gear change. Makes complete sense and my guess is you'll love it. Lower pitch prop should also help keep the boat on plane better for towing the kids around beings the Whipple doesn't mind tugging low rpms :)

Please keep us posted.

Nice work...

Dave

My boat absolutely loves the 1.34 gear... probably because of the very flat torque curve of the Whipple.

You are correct in that it actually planes off quicker using the 28 bravo with the 1.34 gears as opposed to the 32 bravo with a 1.5 gear.

An additional advantage to going to the smaller props, is that my slip numbers went down about 4%.

A P5x is really hard to beat for all around family use... they come out of the hole like they were glued to the water, and midrange cruise is a couple of mph faster than the bravo's. This makes them ideal for pulling water toys or just cruising.

For all out speed and handeling, I like both the bravo's and the Hydromotive Q4X props.. the Q4x's seem to be faster than the Bravo's... but I have not tried a Merc Lab Bravo yet.

Probably because of its 15" diameter, the Q4x slips a little more than a bravo coming out of the hole, but from there on out is 1-2 mph faster per given rpm.

I will be trying a 28 Q4x and a Merc Lab Bravo 28 this next week, and will return and report.

Chris

I think you would shock a bunch of people at the LOTO shootout with the speeds you are reaching! I know you are not close to LOTO but man it would be sweet!

Jt

Nice work Buddy !!!!!!

great numbers chris
 

now you know why i stick with my 32 bravo. above 94 or 95 the five blades are a handfull.

Yup...
but I can also tell you that my boat is faster with 1.34 gears and a 28 bravo than it is with 1.5 gears and a 32 bravo.

Chris

That's because your spinning the prop shaft faster. But you loose a bit of punch. You have enough HP that it is probably not that noticable. It is probably easier on the outdrive also.
Less torque.

1.34 or 1.36 I keep forgetting.
I regeared also.

The upper gear ratio in an SCX is slightly different than in a SC or Bravo upper. Using a SC lower with a Bravo upper nets a 1.36 overall ratio, wherin with my SCX upper, the overall ratio is 1.34 using the same SC lower.

Probably because of the nearly 900 ft/lbs of torque, I did not notice any difference in acceleration.

Chris

It seems, for me at least, that the lower pitch props also lower slip. I tried the 28 lab @ 5750 ft. elevation hit 81 @ 5700 rpm. These are about -2 speeds my 32 lab gets @ 5100 rpm at 4400 ft. elevation. Of course the 28 bounces on the rev limiter @ lower elevation & gains me no speed (in fact I loose 1-2). 15-16 slip for the 28, 17 for the 32. The 28 was stable as could be, could take wide turns @ WOT in 1-2' chop, something that the 32 makes a handful driving straight. It's all about trades, hole shots, cruising & handling.
I wish I could afford what Chris is doing with drives & things, seems you figured this all out.