Shorter lower drive units
 

Does anyone have any experience with adding shorter Bravo lower units to a 32 in order to raise the X dimension? I have been advised not to add any more power to my engines (600) while retaining Bravo One drives. I really don't want the additional expense of moving to heavier duty equipment (speedmasters etc.) in order to add more HP, but wouldn't mind a few additional mph's if simply installing shorter outdrives will accomplish it. How will this effect planing? I know it will be worse but I wonder how much worse. How much more top end?

Curt, I have the same boat and was wondering the same thing, also how would boxes work on a 32

Regarding the boxes, I had it pointed out to me by an APBA racer that Reggie built "an extention box effect" into the back of the transom from the factory. Take a close look at your transom beneath the swim platform. You will notice that the drive housing sits about a foot behind the bottom of the "runing surface" or pad. I had never thought of it that way but that is exactly what the extention boxes are designed to do...move the drives away from the back of the running surface. So based on that he told me that I would be wasting money on boxes. Leave it to Reggie, he knows all the tricks!:p

[QUOTE]Originally posted by Curt
. Take a close look at your transom beneath the swim platform. You will notice that the drive housing sits about a foot behind the bottom of the "runing surface" or pad. I had never thought of it that way but that is exactly what the extention boxes are designed to do...move the drives away from the back of the running surface.

The technical term for this trick is known as a "notched transom"

Their is MPH to be had their. It is just what you are willing to trade for it. Dustin Whipple gave me the name of a dealer that put 1 in shorter lowers on his 35. Boat ran 3-4 mph faster, but was harder to get on plane, especially with a load, fuel, people, ect. Benny Robertson, when he was still with Fountain, said 2 in shorter lowers and 5 blade Hydromotives was worth 4-6 MPH on my 35 twin step. Never tried out his advise, and he isn't with Fountain anymore. The less drag the faster speed, but it can really be expensive and time consuming testing props. If their was someone with a proven combination it would sure make things easier.

Beak Boater, that's exactly what I am hoping someone will provide here. A proven combinaton that works. I've been through a God awful number of trials and tribulations with engine parts and props already. Hell I could write a book. I really don't want to purchase shorties and then find out I can't plane off with me and a beer cooler on board! It's hard to imagine that 1 or 2 inches can make that much difference. Where did Benny Robertson go?


Hey twinn29, I knew there was a term for that "trick" but I could not remember it for the life of me when I was posting. Thanks for the refresher.

Beak Boater,

Gator One has run -2 sportmasters on his 35 with different gear ratios and several different props. He would be a good person to talk to about results.

Curt

I have the 2" shorter sportmasters on my lightning and they made a difference in performance and handling.

Step have you been able to try yours

What was the increase in performance.

Gatorone,

Haven't put sportmasters on the boat yet. Bought new XR uppers to mate them to, so I'll be swapping out whole drives. I have to change the gimbal bearings, boot sleeves, and insert trim limiters in the trim cylinders. (converting from upgraded Bravos to XRs).
What props did you end up running? I've had a couple people tell me to try Herrings; good out-of-hole, good cruise, and minimal top end loss. Did you try these?

Step