5" or 6" Mixer for 270HP B Series?

Pat, be sure to include specifics of any “turns” , any 45’s, 90’s, etc…

Try this if you really want the “engineering side” and not just a “off the cuff” comment…………………….A solid sketch of all the proposed components, there sizes, and all dimensions of the entire system from the turbo outlet to the exhaust exit.. Top, and side /elevation views in relation to the LWL..

A example attached..

You put you time in, and I’ll put time time in you need to sort you out.

Tony

It’s not just the mixer size that determines the back pressure of the system, it’s everything else after the mixer.. We just redid and “doomed to failure 6″ system a pair on QSB380’s with 5″ and the back pressure will be lower with than that the 6” riser system that was removed..

Tony

The Cummins 6BTA 370 in my lobster boat has a 5″ exhaust through the boat and a custom made Seaboard Marine mixer. I could not fit a 6″ exhaust under the deck.

Ordinarily the 370 would require a 6″ exhaust but Tony suggested “de-tuning” the 370 to around 315 hp by grossly under propping the engine.

I don’t see why you can’t get by with 5″ on the 270 but Tony will see your post and give you the correct advice.

Regards, Bill D