K&N flame arrestor

[wca_tim]

Re: K&N flame arrestor

Interesting article...
I also have a corvette, ls6 z06,
I'm sure Tim knows this, but for others... When you change the air filter and or air path to flow more air than the "factory tune" you have to do a computer re-set that tells to computer to build new fuel tables. It can only compensate a certain % while running from this table. I think the filter could get clogged enough that it would get out side of what the computer can adjust for while running down the road on this table developed to run on this free flowing filter. If you did a new re-set with the clogged filter, either with the appropriate scan tool or by leaving it off the battery and going thru the manual procedure, it would develop tables to run efficiently with the now more restricted filter. The cars in the article must not have been clogged enough to get out side the parameters of what the computer could adjust for, by taking fuel away to maintain proper afr.

Also to others, the corvettes have a computer that relays tons of info to a dash display.... instant mpg, avg mpg, etc. That's prob why Tim is able to relay exact performance of the filter as he is using it.

that's what I'm referring to... it changes the instantaneous mileage running at 80 in 6th gear... I've also got bungs for wideband oxygen sensors in the collectors on my headers in addition to the factory narrow bands...

As to the o/p.. I know nothing specific to your 2006 mpi set up but if you can find a high flow filter that fits and your computer has the ability to adjust to increased air flow on its own or you can have it adjusted to recognize the increased air flow, WOT operation should technically see gains. If gains can be made the market usually provides it. Although they may over-hype the gains.

Others may not realize that it doesn't take much on some set-ups to be outside the range where the ecm tables can accomodate the changes you make - something like 20-25% on the c5 computers and you have to modify the tables in the ecm or the computer can't make it run right (for example, if you add long tube headers, ported heads and a cam - no matter how many times you reset the ecm to factory calibration, it'll never learn a decent tune. It requires different tables to be flashed to the ecm before it can do it's thing, or even run wirth a crap again).

fuel injection isn't rocket science. it involves a couple of relativelt simple control loops that are very good as long as you're in the range where the calibration parameters written into the program are valid...

As far as 0.001% goes... I dunno what percentile i would be in - I almost never drive the corvette without putting the pedal on the floor hard at least a few times (I drive it almost every day...), and my boat engine spends a lot of its time running between 4000 and 6000 rpms... (maybe 20+% of it's run time???, especially this time of year when the air is cold and dense) I doubt I've ever had the boat out (unless carrying passengers where safety or prudence dictates otherwise) where I didn't run it flat out for at least a few minutes. When it's just me, I tend to run the snot out of it unless there are a lot of boats on the water or a lot of log monsters in the river... honestly, it would spend a lot more time at wot if the engine was stock and it would only run 50 or 55...

anyhow, enough rambling... time to go put my daughter's camaro back together after installing her christmas / birthday presents ;-) Cheers!

 

[Tail_Gunner]

Re: K&N flame arrestor

it's not a matter of believing or not believing anything. It's a fact, my highway fuel mileage starts to drop after 3-4k miles, then when filter is cleaned and reoiled, it goes back up. It's not a K&N, but a blackwing, but is the oiled element type similar to K&N... And because of other mods to the top end, 4.10 gears, exhaust, etc... the car isn't running the factory tune. It's been tuned on a dyno with a wideband sensor in the exhaust.

definately relevant to the op's post: K&N filters may be crap, but they certainly filter more than most flame arrestors...

the other thing that bears mentinoing is that MAF sensors do not have a direct linear response - they're calibrated and their response changes depending on the velocity, etc... why do you think that the exact same MAF sensor wil have a different calibration when used on different vehicles?

I read the report of the scientists at ORNL carefully. It makes sense, but is not necessarily valid once you deviate from the stock airbox, nor is it necessarily valid in a marine application (Are we running oxygen sensords and an adaptive feedback loop that can accomodate relatively large shanges in air flow?). There was also not a wide enough range of experimental conditions to draw conclusions much beyond the specific vehicles and conditions they used. Just because someone has a PhD doesn't necessarily mean that every conclusion they draw is dead on the money. no disrespect intended to our scientist friends at ornl, just saying...

no need to be cross btw. it's just a friendly conversation...

Well said....with perhaps some middle ground here. Marine motors are not setup in any way for gas econ so trying to make this a revelant argument towards them is impractical. Ill give you a ideal my mefi 3 was running at 9/1 almost across the entire rpm band...Incredible...acutally it so bad i do not know if that was a correct reading

 

[Scott Danforth]

Re: K&N flame arrestor

While eating the popcorn and reading the post, allow me to interject

Marine EFI is speed density (open loop, MAP sensor and RPM only), any changes to the fuel or air system will require recalibration.

Automotive EFI that uses Mass Air sensors actually measure the incoming air mass and use a temperature trim, however can only adjust within a small narrow window because they use simple narrow band O2 sensors. Unless the vehicle is upfited with aftermarket Lambda sensors and the ECM is hacked to allow use of wide-band, or comes from the factory with wide-band Lambda sensors (Porsche), or is an aftermarket stand-alone system - there is a limit to what the EFI can adjust for.

the MEFI ecm used on the GM engines is not that sophisticated.

Back to the OP's original post. - the K&N filter / flame arrestor will filter out more than the stock flame arrestor, However K&N does not have a unit for your application. Adding filtration can be a good thing where needed.