K&N or Computer

[RiskyinElsinore]

How many of you guys and girls out here think that the Merc 496 ho leans it self down after break in or the K&N filter leans it down.I myself have a hard time thinking that a filter would help sence this engine and fuel system is managed by a computer!!If this fuel system is managed by a computer why wouldn't richen the fuel system for the new K&N filter? idea
[ February 26, 2003, 10:22 AM: Message edited by: RiskyinElsinore ]

[RiskyinElsinore]

Let's here some of your thoughts about this.

[rivercrazy]

My own experience with the 496HO is that the rich condition goes away pretty gradually/consistently over time. I still get a small amount of soot at 25 hours but its a small fraction of what it was during the first 10 hours. I think it primarily the computer doing the rich dirty deed during break in. Im sure they burn a bit of oil as well until the motor is broken in.
I've talked to a lot of guys doing the K&N thing and the vast majority of them say the filter did nothing to change the soot on the transom or added any performance increase. I bet the K&N definately has better filtration properties though and that can't be bad for a motor

[Nubbs]

RiskyinElsinore:
If this fuel system is managed by a computer why wouldn't richen the fuel system for the new K&N filter? idea I'm not too familiar with the 496 marine engine. But, assuming that the following is true:
The pressure drop across the K&N intake is less than the pressure drop across the stock intake.
The mass flow rate through the engine will then increase. If the stock fuel injection system is capable of supplying fuel for the increased mass flow, then the computer will compensate for the filter. If the fuel injection system is not capable of supporting the extra mass flow, the engine will run lean. I don't know about the stock injectors or the stock fuel pump, but the extra mass flow may exceed their capabilities. Again, my information is based on a typical fuel injection system. I'm not an expert on the 496. There may be specifics on the 496 that I didn't consider here.

[superdave013]

Do people really think a K&N replacement sparkarrestor will flow more then the stock one??
I will buy that it filters better but flow better? come on :rolleyes:
Hell, I've seen the stocker on Risky's boat and you can see right through it. I mean, you can almost stick your fingers through it. It's pretty course and I would think pretty free flowing.

[Nubbs]

Sorry, double post.
[ February 26, 2003, 12:10 PM: Message edited by: Nubbs ]

[RiskyinElsinore]

Come guys let's get some feed back here,this is better than the white truck thing?on the 15 fry

[77charger]

i seriously doubt their hp claims.I read a hot rod mag where they actually tested many filters and also a stock one.The best improvement was 3hp and it wasnt eventhe k&n.(where does k&n get their 15-20 hp claim).As for the boat like sd said you can see right thru the stock one how much more flow can you gain i'd rather spring for a computer upgrade.

[ACCEPTENCE]

Who offers the computer upgrade and what is it designed to do for the motor??? That's to say what are the advantages of upgrading???

[andy01]

What you should do is look up a member on this message board that go's by "BowTieRick". He works for K&N and can help you with all of your questions and tell you what it will do. He heads up the marine division at K&N.
Andy

[BowTie Rick]

77charger:
i seriously doubt their hp claims.I read a hot rod mag where they actually tested many filters and also a stock one.The best improvement was 3hp and it wasnt eventhe k&n.(where does k&n get their 15-20 hp claim).As for the boat like sd said you can see right thru the stock one how much more flow can you gain i'd rather spring for a computer upgrade. I know the magazine article. They were actually testing flow rates and it was seriously flawed. They tested at 30" of H20 restriction using conversions of the square law formula when the norm is 1 1/2". They got 3000+ CFM out of a 14" x 3" filter. That would theoretically flow enough for a top fuel dragster but everyone knows in reality, the car would suck the filter right through the injector hat. 15 - 20 HP is the claim on intake kits and it is backed by numerous dyno runs both in house and independent. That translates in a 5 - 7 % HP increase. A simple drop-in replacement filter gives a modest 2 - 4 % gain. We do not dyno boats as they have no wheels and we have chassis dynos not engine dynos. What we have seen on boats is RPM increases of 200 - 400 and MPH gains on GPS of 1 - 4 MPH. Problem with that is they are subject to water cnditions, etc. Also, on board computers do not suddenly change the way they work after time. They get inputs from sensors and adjust fuel and timing accordingly. A great deal of the initial soot is actually oil as the 496 likes to burn just like the old 502 and 454. The K&N allows for increased air flow which causes the computer to deliver more fuel. The burning of the fuel is what actually makes power. Having more fuel and air in the combustion chamber helps burn off more of the oil and cuts down on the sooty residue. All the Tawain knock off companies make crazy claims and make legitimate companies like K&N seem like they are full of it. Trust me though, I have never worked for a more honest place before. They are into integrity big time. That is why you will never see a K&N add bashing a competitor even though they do it to us regularly and untruthfully at that. And I would never lead a fellow boater astray.

[77charger]

thanks btr for the info and an explanation.Now the 2-400 rpm increas is that from the whole intake kit?to me that sounds like more than 15-20.I dont know for sure how much hp it takes to gain for every 100 rpm but a jet i do know for sure that it takes roughly 25hp to gain a 100 rpm or so.which i kinda tested myself with a nitrous kit (100 hp)which resulted in a 400 rpm increase and an 8mph gain.But like i said i only know jets but i am curious to the prop hp to rpm ratio since i now own a prop boat.

[Rexone]

We've had similar reports from customers like BTR stated. Seems the K&N filter is enough larger surface area than the stock arrestor it flows significantly better along with the filtering advantage of keeping dirt out. I have not had a 496 personally to test but generally customer feedback on items like this is pretty accurate, especially when you get many. :)

[spectras only]

Mike, I like K & N in my cars for their longevity and reuseability ,but what's the dealio with filtering dirt on the water wink .Nobody runs their boat engines while trailering :) ,and I have my carb covered while in transport. If there wasn't a UCG regulation for the use of flame arrestors for obvious reasons ,a lot of folks would run velocity stacks like the old days to achieve max flow.I've never experienced any rpm gains without my barbron arrestor off ,or a K & N on.As I mentioned in an earlier discussion about K & N gains , K & N only claims better flow against OEM factory paper elements for cars .Is there a claim on the marine K & N's ? I recommend K & N for cars 100% ,but like the look of a gaffrig S/S in a boat :p .Lets flame away :D :D

[Rexone]

All I'm saying is that we've had many customer reports on the Merc 496's and earlier MPI's too of rpm gains vs the stock Merc arrestors. As far as dirt and the filtering aspect, probably not major factor unless you're running in the desert areas where the wind often kicks up lots of dust. Then I can seeing that being a big plus in that situation. As far as comparing it to large barbrons or gaffrigs air flow wise those are probably better. But they don't fit these Merc engines either so it's kind of irrelevant.

[spectras only]

Mike , I agree on the use of K@N on the mpi engines where the filters are mounted differently than the carburated models. Ps; do you still have the 80MPH rex sport series speedo units in stock ? Do you have chrome bezeled units similar to the ones pictured on your website, cause I'd like to match one with my original S/W set on my dinosaur spectra.Thanks
[ February 26, 2003, 11:07 PM: Message edited by: spectras only ]

[Rexone]

I do have some 80 sport series left but they are the plastic type bezel (clear looking bezel portion) like on the older nordskogs (same mfgr.). Don't have any that look chrome to match the SW. :)

[Dribble]

RiskyinElsinore:
How many of you guys and girls out here think that the Merc 496 ho leans it self down after break in or the K&N filter leans it down.I myself have a hard time thinking that a filter would help sence this engine and fuel system is managed by a computer!!If this fuel system is managed by a computer why wouldn't richen the fuel system for the new K&N filter? idea Unlike automotive fuel management systems, the marine system does not use an O2 sensor (it can't). The marine sytem relies on inputs such as throttle position, engine rpm, and engine load to adjust short and long term fuel trim. The auto system strives for an A/F ratio of 14.7:1 (cleanest) and also switches from rich to lean to control NOX. The marine system is looking for about 13:1 (optimum performance and less detonation). The marine system is a compromise. It doesn't really know if the exhaust is rich or lean and can't make adjustments based upon that input. Therefore, a slight increase in air flow would have minimal effect on fuel trim adjustment.
(Note: Marine systems do not use Mass Airflow they use speed density).
[ March 08, 2003, 09:26 AM: Message edited by: Dribble ]

[Mandelon]

RiskyinElsinore:
Come guys let's get some feed back here,this is better than the white truck thing?on the 15 fry I think that white truck was running twin 600's with K&N Superfiltromatic 2000's...... :D