stopping a flat bottom from porpoising...
 

Have a 99' Top Gun with blower motors, 5's on boxes that run level with the bottom of the hull. Cant seem to stop it from porpoising. Once i trim up in the sweet spot and hit a wave it will start, drop the drives down and it goes away, but i can feel the boat drag and slow down, If its completely calm im fine.....What seems to be the fix for this problem? Ive tried spinning the props in and out out helps a bit...

On my 1997 Gun we lowered our X dimension a few inch's with the addition of drive spacers & we went from 87 to 94mph and also stopped running like Flipper.

Night and day difference on our hull.
Good luck!

I still have new spacers, if you can use them.

Gary

Thats why you need a constant 3' to make the hull happy... :)

X
 

Agreed, your X-Dimension is a little too high, the spacers should make a big difference. You may see an improvement with 1" spacers but 2" should be right on the mark. What length trim tabs do you have? If you don't already have them, 380's will help the combo as well.

Not mine thats for sure!
-Mike

If you are in your "sweet spot" I would use tab input rather than drive input to settle her down and then when it settles out you can ease up on the tab input. A little bit of tab goes along way and you aren't scrubbing as much speed either. I agree with everyone with respect to your X being a little high as well.

what speed is it starting at?

id call bblades and tell them what you dont like about the way the boat acts, send them your props, and try it after they do their thing. my boat chine walked and everybody told me do this and do that. i sent my props out and had them labbed, now it runs like its on rails. just a thought.....

props have helped the porpoise in my boat, more blades