One way to tell is buy putting bungs in the tailpipes and use a manometer to check back pressure. But as stated prior, your supercharged, I really don't think your hurting it that much. Or you could take your hatch off, take off the Y tail, and turn the two tails upward with hoses run overboard to dump water and run it and see if you turn more rpm.

FWIW, TORC series trucks run Ypipes like that. However they turn some major RPM, like 9K+. They sound bada$$

what is the power level at now with the quads?

990 h.p. on the Dyno.

Well your not getting 990 hp with a 5" two into 1 Y pipe. Are you looking to get more speed? That boat has to be fast as hell the way it is.

My main point to posting was just to determine if this was the best set up for the boat. I like the exhaust tone with the Y pipe, kind of a high pitched wail. I do want the Talon to go as fast as possible. Yes it is fast but how fast is fast enough? I will try some conventional tailpipes this season and report my results.

How fast is fast enough??? Well when you see God pull back....... lol

Given the price of new exhaust and the hastle, even if it just tails, I would not think it would be worth the money. You just said you love the way it sounds... Also, you would probably have to cut into the boat for the outlets.

why not see if Imco or someone will modify the tail to 6"? That should handle the flow I would think. I talked to stainless marine about fabbing Y pipes for me and they said they won't do them anymore -- wouldn't really go into detail why -- just said no...

Or just run them as 5's -- might cost you a bit of power though at top end -- nice thing is with the FI you can tune it for them better than carbs...