Few Questions about my Blown Scarab.....

[OliverM5]

Just finished rebuilding my 1997 23' Scarab SCS with a blown 502 (about 750 dyno hp)......I took it out for the first time this weekend and it got a little unstable at about 75 mph when going across small rollers....so I pushed the trim tabs down (Dana 1000's) and it made it more stable, but speed was limited to that area.......the last owner said it GPS'd 89 mph.....I had 2 extra passengers with me (they were about 500 lbs combined) as well as a 3/4 tank of gas in 120 degree heat - how much can I expect that to take off the top speed for these factors and how exactly do the trim tabs work on a boat (how do you use them) and still get top speed?

[OliverM5]

Anybody? :cry:

[Deano]

Anybody? :cry:
tabs are used to correct the attitude of the boat. I think the best way to use em in somewhat rough water is to trim a little high on the drive and then bring your tabs dow a hair to compensate, which would have the drive and tabs working against eachother to stabilize the ride.
As far as the speed??? Im not sure..120 is pretty frigin hot air even before it hits the blower..
one more thing...when you say "alittle unstable" going over small rollers. I dont think thats really enough reason to be dropping the tabs down. It will stablize the ride but..you will loose alot of speed.
That boat is going to be alittle unstable at that speed anyway. Keep the tabs up if not a hair down and use your drive to correct. The drive moves way faster than the tabs and will get you under control alot faster without loosing alot of mph.
other than that.....nut up and hang on.. ;)

[djunkie]

120 degree heat is a killer. I lost almost 10 mph in my boat this weekend in that heat.

[Deano]

120 degree heat is a killer. I lost almost 10 mph in my boat this weekend in that heat.
He probably lost 10mph from heat and 5 mph from the tabs being too low>>>there is your 90mph :idea:

[Pointerman]

Use your tabs to correct attitude due to load and other misc. issues. Primary use for tabs is to keep bow down in rough water. Don't use them to correct a squirly ride. You just got to drive it baby! :D