fountain4play

I have a 3600 Nor-Tech Cat with Eddie Young 925's running Arneson ASD-7M's since 2010 and have never had an issue with them. They are great drives and work great.

ICDEDPPL

How do those engines run?

fountain4play

I've had my issues at the beginning but they've been pretty good for the last five or six years.

im MartinB

The boat just has stock 525 EFIs in it right now and with 7 people onboard and half tanks the boat jumped right on plane. I did try my labbed 30s and the second the bow came down the props blew out, but I'm sure that was because the diffuser was completely removed. I wonder if he had his X dimension raised. I've been looking at the bottom all week and I have to say it's pretty darn straight... I wonder what he ended up having them do to it.

im MartinB

So say said tunnel requires 85mph to pack enough air.. ie create enough pressure to lift said boat.... If you use a tunnel tab you are essentially increasing said pressure so this should create more lift at said speed... IE if you set tab to reduce the exit side by 20% this would theoretically increase the pressure in the tunnel thus creating lift. I don't think this would cause a boat to be prone to stuffing the nose except when the boat was moving fast enough to pack air already and then tunnel tab could possibly cause too much pressure.. but even then in order for the bow to go down the transom would instantly be opening thus decreasing the pressure.. It's not like a tab that is in direct contact with the water and thus always creating transom lift.... It seems like a large tunnel tab would be an asset on almost any catamaran.... My dad used to tell me all kinds of stories about Pete and issues with Skaters and all the different ways they would fix them... and the most common issue was porpoising ... But he can't ever remember them using a tunnel tab... Hopefully there is enough of a community here that we can share some actual results.