Exhaust baffles?

[John Doerfler]

Does anybody know what would make my boat perform better.  Exhaust baffles in or out?  I have an 83A/S with the 350 Chevy.
John Kyle Doerfler

[Mike Harry]

Usually less restriction = better performance on any engine

With that being said, if you change pipes...... be sure you adjust your air/fuel ratio on the carb

[John Doerfler]

Well, I am asking because I am a Harley Davidson mechanic and have been for 11 years.  Long enough to know that less restriction can equal more peak horsepower, but having a straight through exhaust system will always to kill your low and mid range power.  Drag pipes on a Harley Davidson sound cool but they perform like crap on the street.  It seems to me that the water flowing out the exhaust has some of the restrictive qualities neccessary for a good performing engine but I just wanted to know if anybody knew for sure the affect it can have if you remove the baffles.  I think I will try it and see how it feels on the lake.
John

[Mike Harry]

If I remember correctly, the older boats had strait pipes (think I came across that somewhere here on the forum) Im sure Ron knows best. Whats your powerplant? The chevy based block or the Ford base?

Ive had no troubles asking Indmar questions about my motor. They have always been willing to help me when I was in the rebuild and trying to bolt in/on a little more power.

If you have not already, they told me to take off the old 200 pound boat anchor of an intake mani and put on an aluminum instead. This was a no brainer for me, but that was the first suggestion they had.

[John Doerfler]

Great advice man but my old 83 came with the baffles I think.  It did when I got it anyway.  About the manifold.  My boat has the 350chevy and that motor came with an polished aluminum manifold already.  Its a really cool looking motor.  Did you put an aluminum manifold on your 351ford?  Did you notice perf gains?  Do you have the baffles in your exhaust?
John

[Joel]

Guys,  Ron commented on performance upgrades in another post today or yesterday I think...  He basically said that you'll spend a TON of $$ for very little improvement in performance - at least top end anyway.  Just something to think about before you go off spending a bunch of bucks...

Anyway, the older boats (way older) had straight pipes and they have to exit under water (for the muffling effect) but it is still VERY LOUD!  My 91 Advance has the mufflers (baffles), but I'm sure there isnt alot left of them...  If I had straight pipes on it you wouldnt be able to sit in the back while underway.  She sounds pretty awesome now anyway 

[Mike Harry]

If its already aluminum you are good to go. It gives you a little more flow over cast iron, but the huge gain is in weight. I have not had my boat in the water yet, so I don't know about gains. Probly minimum. The weight is where you gain the most. And yes my pipes have baffles, but they don't have much of one. Just enough rise in the center of them to make the water back up in them when its at idle I would guess. Long story short, you wont get to 50 MPH without spending a $hitload.