OMG MY K&N FILTER!!!

[thebarber]

Originally Posted by 1stToyota

And that intial 1hp at the wheels (until the PCM adjusts for the extra airflow that it now sees) that you think you're feeling because you're driving more aggressive to hear the extra noise being made under the hood can quickly turn into about a 20hp loss at the wheels when the MAF gets gunked enough to set a code.

only way it gunks up the maf is if its waaay over oiled. i had k&n oiled filter on my xrs and never had a problem w/ an oiled maf even running to 8350rpm...

its a common misconception that an oiled filter with screw up your maf....its gross user error to have that happen...

as for the hp increase...im sure its almost negligible in the yaris....but the ecu doesnt compensate in the way youre describing, otherwise you would never feel any power increase for any mods done on a stock ecu...and thats just not the case.

how much are those stock paper filters? for me, id rather spend the $50 on 1 k&n and never have to spend money on cruddy, restrictive paper filters

[1stToyota]

Originally Posted by thebarber

only way it gunks up the maf is if its waaay over oiled. i had k&n oiled filter on my xrs and never had a problem w/ an oiled maf even running to 8350rpm...

its a common misconception that an oiled filter with screw up your maf....its gross user error to have that happen...

as for the hp increase...im sure its almost negligible in the yaris....but the ecu doesnt compensate in the way youre describing, otherwise you would never feel any power increase for any mods done on a stock ecu...and thats just not the case.

how much are those stock paper filters? for me, id rather spend the $50 on 1 k&n and never have to spend money on cruddy, restrictive paper filters

HP gains come from real mods, followed by a dyno tune. Try putting a cam, heads and LTs on a LS-1 motor w/o a tune. You'll be lucky if you can back down the drive until it's tuned, and then you'll see 100 or so extra hp at the wheels. And the PCM works exactly like I said...the MAF measures AIRFLOW, that's why a car will still stay running even when the paper element can be completely clogged with dust, trash, dragonfly legs, bird feathers, etc...

And it kinda depends on the location of the MAF, if it's real close to the airbox better chance of catching non-100% air across its heated wires. I'd say it's not a misconception when TSBs are issued on oiled filters.

K&N (drop-ins) is great for saving money but not for HP gains, maybe 1 or 2 hp at the wheels of most applications, at best. Probably saw better gains back when they first came out and was installed in bigblocks with hi-rise manifolds and dbl-pumpers, but now cars are getting too smart for minor mods w/o reflashes.