Re: Remove exhaust bellow?
Exhaust tube, bellows, or completely off, really doesn't effect anything other than noise, exhaust residue on the transom / drive and exhaust fumes in the boat, depending on boat style. The exhaust "tube" is designed so that when the drive is down, it fits nicely inside the tube to direct majority of exhaust through the prop. At idle, the sound won't change between the tube, bellows or nothing at all because it is all underwater anyway and the difference is when on plane and exhaust port is above water. Also, when trying to get on plane, if there is nothing on there, sometimes the exhaust bubbles "MAY" cause aeration of the prop problems.
Having the bellows attached on the smaller / stock engines actually provides a bit of performance increase where as the low pressure venturi effect at the prop while on plane, actually extracts the exhaust from the exhaust system, reducing the exhaust back pressure some.
There are no performance gains to be had with the mod on a 5.7L engine. Even with a stock Big Block, there are no real advantages. I tried it on mine and the noise increased considerably while on plane (Admiral was complaining), as did the exhaust fumes (see 1st Admiral comment) and performance changed not one bit to an advantage, but may have actually gone down a tad. Bellows went back on..... Noise of exhaust drone (I liked it, but was in driver's seat) and exhaust fumes for those near the back of the boat got quite annoying after a very short period.
If she aint happy...... Well, you know the saying.
Your mileage may vary.
