Exhaust Opinions??

[1997chevydriver]

1) Nice boat

2) IMO headers 2.25"-2.5" Pipe to either 2 in/out muffler of your choice or 2 muffs of your choice to tips out the back.

3) I can already see where this thread is gonna crash and burn at Play nice boys!

 

[MOBS]

As far as I can tell when it comes to the "back pressure" subject, is that with a boat, it imitates load on the engine. With an automatic, there's always some sort of load on the engine. If the OP put a longer exhaust duration cam in his engine, it's not the lack of back pressure, but instead he's lost his off-idle torque due to raising his operating power band.

 

[am92]

I didn't think about how it simulates load on the engine in a boat, that's a good point...and I'm not trying to be rude, just trying to disprove some common theories that have a lot of evidence saying otherwise. Good choice on the thrush weldeds though, the best sounding truck I've ever heard was a NBS 2500hd 6.0 with 3" duals and thrush mufflers

 

[Solid94]

I'm running the factory y into 3" pipe to the cat then to a flowmaster super 44, 3" in 3" single out to a 4" dumped tip. Sounds throaty and not a lot of drone in the cab. I have plenty of back pressure with the 3" pipe

 

[Green Machine 92]

It runs a lot better now. Also its the quietest its been since i owned it lol

 

[Silverick]

That's a freaking sweet boat, and while it may have ran better, it wasn't from the back pressure. The baffles may have changed the tuning of the pressure waves to help with scavenging and that is why it ran better. For anyone that's more interested in the science behind exhaust systems, there is a great article here http://www.superchevy.com/technical/engines_drivetrain/exhaust/0505phr_exh/viewall.html that explains everything very well

The boat is real sweet and runs as good as it looks!!

You may be correct regarding the pressure waves and the scavenging....

I have another story regarding a small block Chevy that ran great and had single exhaust. Stock motor with an automatic and I ran full 2 1/2" dual exhaust from the headers all the way out to the back with a pair of glasspacks.
The truck sounded great, the exhaust system looked cool but, it lost the bottom end snap that it had with the stock exhaust set up. Ran great on the freeway and I probably gained a little something on the upper end of the RPM range. Since this 'mistake', on a mild street engine, I have paid attention to the primary pipe sizing and have always installed larger tailpipes - after the mufflers - for the larger size tips that I like....

Just a real life story.....