Whipple Charged

Yes, multiple changes in calibration. Also, this is not the same on the ETC motor, that restriction is calibrated in.... We calibrate it out....

BUP

iTrader: (9)

The newer 8.2's have the one cat per side positioned horizontal. The 496 have 3 cats preside mounted in the vertical positioned. Merc and Volvo use the steel sub strake in which is more durable than the ceramic sub strake .

In a marine app the cat can be easily damage with things like running the engine out gas, constant misfires over time, water reversion kills them on the spot, very lean conditions, high levels of zinc and phos in your motor oil over time and or if you have excessive blowby past the rings, even the wrong gasket sealers over time can hurt the cat. Anyways 3 drop out cats per side can be very expensive if they get damaged,

If I recalled Merc retail is 1200 per each cat for that app of 3 per side - total of 6 cats or 1800 bucks for the one cat per side that mounts horizontal for a total of 2 cats. My point to this is. make sure you keep your motors in well tuned and have an accurate gas gauge along with no self induced water reversion no matter what cat you have in your exhaust system.

IMO the current catalyst marine engines running around now in 5 to 10 years down the road, I can not see how these things are going to stay reliable. just my 2 cents.

Keith Atlanta

496's dont have cats. Mine didnt...

BrianH244

[QUOTE=Whipple Charged;4108809]525HP EFI has a different bolt pattern at the cylinder head/exhaust flange.

CMI 496 exhaust is a direct bolt on and better than stock. Stock has more tight bends and even without the cat, will not flow as much as the CMI.... Can't tell you the difference in power, we didn't test stock

Dustin, I pulled the cats and will be using the stock exhaust. There shouldn't be an issue running this setup with the stage II kit, right? I heard it could harm the motor if I tried to run the boat after pulling the cats without a proper tune. Also will I keep the o2 sensors plugged in? Wasn't sure if they would still be in use after the tune. I'll be sending it out Monday.
Thanks, Brian

BrianH244

BUP, I have a 2011 8.2 mag and mine has the 3 cats per side. Also anyone know where I can sell these cats?

Keith Atlanta

[QUOTE=BrianH244;4108867]Interesting...

So basically, Dustin can program the O2 sensor that is already in your engine to force the injectors to provide the engine with a certain amount of fuel "per" the program and achieve a certain AFR?

That is badazz!

BrianH244

[QUOTE=Keith Atlanta;4108870]I'm not sure how any of that works. I didn't know if the PCM tune tricked the sensors or will they need to be unplugged?

BUP

iTrader: (9)

Yes I understand the first year or 2 of production 8.2 's had the 3 cats per side then Mercruiser went to the single cat per side for the next following years to current. As what I wrote was not to clear - " the newer 8.2's "

EPA along with CARB for California in 2008 required all 2008 year models, marine engines under 500 hp had to have the catalyst system for reducing emissions. All mercruiser black production Inboards and I/Os engines - again anything under 500 hp it was mandated in California for all 2008 year model marine engines across the board and the rest of the USA was mandated for model years 2010 to current.

Indmar marine engines was the first to introduce a full catalyst system for their marine engines in model year 2006 - way before it was ever mandated. There was a reason for it and for the wakeboarding side of it. Reduce emission behind the boat for all wakeboarders and surf skiing. It was becoming a liability without cats as how Indmar looked at it.

The 496 for mercruiser ran out around early 2010 and Volvo penta 496 ran out in 2012. Plenty of 496 marine engines had catalyst systems.

Next tid bit all marine engines including outboards will be standardized for model year 2018 for computer emission controlled engines. Kind of like when all autos back in the day went to OBD II for standardization . Also Outboards have been testing catalyst systems for the last 3 - 4 years but still needs more engineering on the reliability side. The cat system for outboards is coming soon.

rfgonzo

I don't think you can run the motor if the computers not flashed.

Whipple Charged

[QUOTE=Keith Atlanta;4108870]Yup, we can do anything needed to the PCM.