I have noticed all of the 230 Regal/Velocity boats have side exhaust. Can you do a straight exhaust that dumps on top of the swim platform on these boats? Also does anybody have any real world mph on one of these with a 500hp BB in it?

Why change the exhaust? Get rid of the mufflers and replace with a SS elbow. It is not a big radius and you don't lose that much flow.

I would guess low to mid 80s with 500 hp. With a 454 mag with headers I could hit 72 mph on most days. That was with a 1989 Regal (Velocity) 23

I want to change the exhaust because I hate the side exhaust and I have Stellings dry headers and tailpipes that don't work so good with side exhaust. Thanks for the response it sounds like it will run pretty good with my power.

i have a 27 Nova III formerly with side exhausts. they are now rear exit above molded on platform. looks kinda stupid. i sold the boat after side exhausts killed both motors (water injestion when in slip.) friend i sold it to did the straight out transom conv. now i got it back. i don't like the look or the 4 rust stains running off the platform. but it fell back into my hands at an offer i couldn't refuse. i am also replacing 1 motor, worried about the other, and learning to do boat upholstery work. the way the exh conv was done was to sawzall roughly 6 inch square holes in transom to feed exh hoses through. then drilled the 4-1/8 holes in the platform's vert part and mounted tips there.

Regal Velocity. i am looking at one right now for next year's back bay boat. $2300 with missing interior and small block. less than your Stellings are worth. the boats are around 10k perfect, so not many people are gonna cry blasphemy cuz you cut holes in the back. might be an idea to keep side exhaust outlets in place and seal up inside where hoses connect. the flat plates screwed over the old exh outlets on my boat also look dumb. then keep the old exhaust plumbing to go back to that style when you throw a 350 in it to get rid of it.

I had ligtning's on mine. As I said my mechenic had ss elbows fabricated to replace the muffelers and just ran exhaust hose from the headers to the elbows. The side exhaust is somewhat loud. <g>

Good luck and let us know how she runs.