louisfever

Hi guys
Im thinking about installing a 12 inch extension box to my scarab 29 and would like to know if anybody has done it ..
Has anybody out there installed an extension box on a scarab 29 and did it make any difference in ride quality and speed ???????
My motor is a 570Hp 502 I built
Thankss

blaquebaja

What's the spec on your 502?

louisfever

9:1 cr carburated 502
800CFM carb
Dart 308 iron eagle heads with Inconel valves
Camshaft from the 525EFI mercury racing motor

louisfever

Short block was rebuilt a year ago

Team Archer

The main thing to remember is that when you go back you need to go up also. 12" back equals 1" up.

louisfever

Yep I know that thanks
I was told to go up more !!!!!!
I was told to go up 3 by a pro in the marine industry !!

Team Archer

That's because all Scarabs the drives are mounted too low we put 2" shortys on most of them whitch helps a great deal

louisfever

Last winter i closed the transom and raised my X dimension 3 inches
Brought the slip from almost 20% to14 - 15% which is great and gained 3 mph !!!!
My nose cone now is aproxx 4.5 to 5 inches below the Vee of the boat !!!!
If I put an extension box on it, should I raise the height another 2 or 3 inhes again or keep my height and go with a neutral box ?????

louisfever

Im sure it will help the boat by setting back the drive but im scared it wouldnt have enogh leverage if I go higher then I am !! (being 3 inches higher then stock)

scarabman

If you go with a neutral box, you are pigeon holed with what you can do. If you go with a + box, and you can always space back down. At the very least, if you are happy/comfortable with your current setup, as was already mentioned you need to go +1 to maintain.