Robert and some others have talked about "aggressive"X dimensions on Fastechs.
How different than the factory "standard," and what's the impact on performance/speed?

Could the same result be achieved with a shorter lower unit?

I'm particularly interested in the 382, but any info would be appreciated.

I would try and get in Touch with Eric Tredwell on the general discusion board. He used to race them and have helped a lot of guys set up thier boats for max performance.

Jon

MY 2000 382 HAS THE EXTENSION BOXES FROM THE FACTORY, I RUN 28 PITCH PROPS, A FEW SUMMERS AGO I BOUGHT A SET OF 26'S FOR LAKE POWELL ~4,000 FT ELEVATION. THE BOAT CAME OUT OF THE HOLE LIKE A ROCKET BUT ANY AMOUNT OF DRIVE TRIM AND IT CAVITATED BAD, SO BAD I HAD TO RUN THE WEEK WITH THE DRIVES TUCKED IN. THIS LEADS ME TO BELIEVE THE THE X DIMENSION IS PRETTY HIGH, MAYBE TOO HIGH? IT ONLY CAVITATES WITH THE 28'S OUT OF THE HOLE A BIT FEATHER THE THROTTLE AND GO

ApachePete

I have a 1999 271 that I tried an Imco 2" shorty drive on last year. It took about a half mile to get up on plane and that was playing with the tabs. I wondered for awhile if I was even going to get on plane at all. Top speed with the shorter drive was about 2 mph slower. I borrowed the shorty drive so i wasn't out any money for it. The 382 might be different but the 271 sure didn't like it.

271-- did you try a 4 blade prop? It probably would have solved your planing problem and you may have picked up speed with the bigger prop.

Tinkerboater,

I am already running a 26p Bravo 1 4 blade. I usually don't have a problem getting on plane. I think the X dimension is already high so shortening the drive height made it too high. Formula does their homework when designing their boats as I found out with the Imco shorty drive.