I have a buddy who just bought a 2014 Four Winns 265 that with the new 8.2L with big single CATs on each side. He hates how quiet it is!!
I see that Whipple offers PCM reflashing.

https://whipplesuperchargers.com/ind...&product_id=54


What exhaust will work with this? He has the 380HP base version with Smartcraft DTS....
Wants it to be louder and bump the HP a bit.

Will any 502 stuff work on it??

The heads and intake on your app r from Edelbrock and the Cat is not as restrictive as you think. Actually Merc and Volvo pick up a tad horsepower when the Cats came into play because of the added 2- O2 input and 2 - O2 output sensors that was never installed before without the Cats. The O2 sensors reporting back to the ECM has measured more precisely the air fuel ratio hence a tad increase in Hp. Also removing the Cats on a 3 year old to brand new boat voids all the complete warranties. I would wait till the warranties are over with, then see what options are out there. Just my 2C. All marine CAT engines have a 3 year / 480 hour warranty which ever comes first unless you buy the BS extended warranty.

The boat is literally a week old! lol

Its more that it was advertised as going 65 mph and he's only 55mph. Also its much quieter than he wants. He had a previous 4 winns with a 350 with side exhaust that was much louder! So he's disappointed that his new boat with a bigger motor is quieter and slower.

The heat generated by the new cats robs power, as it heats the intake air. Extra vents were needed for the 33AT that we installed them in. I think the same for Sunsation.

Rambocj7, is the boat now running at altitude?

They need 800 degrees to even start to work properly. Plus run your boat out of gas and it will blow a hole straight through the cat. Also water reversion will do the same and ruin it as soon as the water hits the cats. Also the missing / miss fires of ignition components over time can kill the cat(s). Raw fuel as well and High Zinc & Phos based motor oils will kill them over time as well..

Funny your new boat since 2010 under 500 hp has to meet these very strict marine emissions but the billions of Autos in Florida do not need a emission test to drive up and down Florida all day long. No inspection at all, this completely puzzles me especially if the auto or big work truck is even road worthy along with passing any form of emission testing. I understand for a cleaner earth but lets start with all the states that do no have any emission testing period for the billion of autos running around. Just my 2C.

Hey don't be giving anyone any ideas. I live in one of those no test states and my cats were removed at 260k.

Not too mention the carbon foot print of China right now :/

I call it being part of the 1% group, we are too easy to pick on. EPA makes a stink about everything, but if a politician or the EPA is looking for justification of their jobs, they just attack the 1 percenters and lose very little votes.

Motorcycles, snowmobiles, jet skis, boats, atvs have all taken a beating in the past 10 years.

Boat is running at close to sea level in fresh water.

My friend mostly hates how quiet it is!!

It sounds like your friend spent a lot of money on something he didn't really want? Is it through prop exhaust?

even in no emissions test states removing cats is illegal. if a cop sees they ain't there...big ticket. i don't know if the same is true for boats with cats yet, but it will be in time. so if you pull them, keep them safe and with the hardware need to reinstall them. they are also EXPENSIVE!! does his boat have those muffler tips on the exhaust outlets? that's whats gotta go...