I'm interestd to know what kind of power upgrades have been done to Merc 575 sci set-ups.

How much boost do they run in the stock / factory configuration ?

Your expereince or redirect to reference info appreciated.

I had a set 575 sci in my Top Gun, From what I understand the best upgrade is to actually reowork the motors a little, different cam, different valves, rockers, etc.. If I remember right the boost is only around 5 - 6 lbs or so, if you go any more you will blow the motor up. My motor was reworked and was getting around 650 - 675 HP with a mild cam.

Stock boost is about 4#. An innercooler, pulley change and ECM flash will get you to about 650HP.

Mine are at about 650 now with stock pully. Best was 715 or so on dyno I had him back down due to NO 93 in OK,
New heads punched out to 509 and just about everthing else.
Call Brad Smith you wont be sorry.

Ron Potter built mine up to 700+. They are awesome! New cam, massaged heads, roller cam, pulley, and ECM.

something like this?

http://www.youtube.com/watch?v=25XxQ2eiuYg

Now where is that smiley face!

I have done several of these and we put Dart heads, cam, innercooler, program the ecu and get 730HP.

If you don't mind working with an engine builder that is some distance away from you, Tyler Crockett in Michigan.
http://www.crockettmarineengines.com/

Hint: Who ever you choose, get several OSO member recommendations BEFORE you decide. Please don't become a member of the "Beware---Stolen Thread" club. We have enough of those already enlisted.

Dean Gellner supplied the stuff for mine
( heads, hr cams/lifters, ECM upgrades)

216-398-8500

They run great