Has anyone tried extension box on a 27 or 29?? If so how did it work out?

anything to get the drive up would help . But it would be scarey w too much hp.

Yea just curious if anyone had some data of doing it. I am putting a -2 imco on the boat as I did some testing with one and without changing props it went the same speed but at a higher slip. I have to replace my drive so I am going to get a -2 with some spacers and see what works the best. But also considered an extension box as well. I bumped power over the winter, and looking into speed gains in efficiency, bottom, and drive line at this point.

If you can get it high enough to run a Maximus 5 blade or a herring. You will have much lower slip numbers that ever before. I am at about 11.5 ( different boat than my old 27). With the prop style I ran on my 27 i got 6800 rpm s at 83 mph. With the herring it's 98 mph at 5600. So gut your drive up. Contact Bblades and rent some props

there is one that ran 104 at LOTO a couple years back. The center of his prop was even with the bottom of the boat. ( or close to that)

Looking like I'm probably going with an AADS phase 3 build with cryo'd XZ gears. I am going to stick with 4 blades, 5 blades are just too hard on bravo drives. That's crazy fast for a 27 fever lol. I am just curious if the extension box itself is worth any positive speed gains, or is there a better place to put the money

Not a stepped hull, but I beleive JimV is running one on his 27 with big power. Money is probably better spent on custom prop work.

I am going to play with the -2 imco, spacers, and then eventually prop work once I figure out where it likes the X dimension to be.

i have a 27 with a 800hp and a 27p 4 bade it starts chine walking hard in the low 80's had it up to 85 on friday but it was like glass on the lake any suggestions ?

What year is your 27?