K&N Air Filter

[Chris Kennedy]

I have an '81 4-spd. and have been using the K&N Air filter for this model for some time (stock, round air cleaner, nothing aftermarket except air filter). Frankly, I wonder if this air filter makes any difference over the stock AC Delco at 25% of the price. It looks nice, but.... Also, I think the cleaning accessories are an expensive and ridiculous mess unless you have some sort of specialized set-up. Anyhow, I would be interested in others' opinions on these K&Ns. Are they really any better, or are the performance claims marketing hype?

Thanks,

Chris Kennedy

 

[81LT4]

Whats Up

I found your DIVERTER VALVE Chris

 

[Whiplash]

I have an '81 4-spd. and have been using the K&N Air filter for this model for some time (stock, round air cleaner, nothing aftermarket except air filter). Frankly, I wonder if this air filter makes any difference over the stock AC Delco at 25% of the price. It looks nice, but.... Also, I think the cleaning accessories are an expensive and ridiculous mess unless you have some sort of specialized set-up. Anyhow, I would be interested in others' opinions on these K&Ns. Are they really any better, or are the performance claims marketing hype?

Thanks,

Chris Kennedy

Chris,

I run K&N's on all my cars, 2002 Z06 gained 10 hp at the flywheel (dyno'd), 2002 Durango, old 2000 Trans AM, old 1996 LT1 Corvette. They flow much much better and the cleaning is only required very rarely. It's a lifetime filter and it actually flows better as it gets a little dirty.

Just my $.02 worth but flow is everything and these K&N's definitely flow better than the cheaper paper filters.

Cheers.

Whiplash

 

[steves1980]

I always wondered to, as for now iam running the stock AC filter, but was thinking of buying this, http://www.madvet.com/shop?frame=4.135.5795 has anyone used this yet, i think i just may try it after i get my car all done, it still has to go to the A/C shop then to the paint shop, what do you all think about that K&N filter?

 

[Bob_K]

That Mid America setup looks interesting. If I read it right you can keep all of the hookups to everything just ditch the restrictive air filter housing and ductwork. My only concern would be that something may actually be lost (at least in my '79 L-82) because where the stock air cleaner takes it's suction I think the air would be colder. Anyone have any thoughts on this?

 

[Whiplash]

That Mid America setup looks interesting. If I read it right you can keep all of the hookups to everything just ditch the restrictive air filter housing and ductwork. My only concern would be that something may actually be lost (at least in my '79 L-82) because where the stock air cleaner takes it's suction I think the air would be colder. Anyone have any thoughts on this?

I can't remember the duct work from my 78 from the Air Filter Cover to the outside. On my 71 it just draws air from inside the engine compartment. If you have ductwork to the front that gets fresh air I'd keep it and just insert the K&N replacement filter inside the stock cover. Colder air is denser and means more HP. Hot air from inside the engine compartment is a drag. I don't believe the Vette has any type of Cowl Induction action in a 79 so I'd just vote for the replacement filter unless you really like the way the MA piece looks. And I will admit it does look cool.

Whiplash

 

[Bob_K]

I can't remember the duct work from my 78 from the Air Filter Cover to the outside. Whiplash

On my '79 there's ductwork that takes a suction from right over the radiator. Since it's not after the radiator I'm assuming it would be pretty cool air. The only thing is that the intake for it looks awfully small to me. I'll probably just go with the K & N replacement filter and keep the housing just because I'm blowing enough money on other things that I probably won't have any left over for things like new filter assemblies, gas, etc.

 

[AKRAY4PLAY]

Steve,
i have one on my 406. no way i could get the cfm i needed out of a 4 inch filter. i don't think they are really worth the money unless you're running a mod motor. the slight gain in cfm is negated with breathing hot air, but rolling down the road it may do a litlle better than stock. cleaning is a pain, as mentioned above. one other thing, do not over torque the wing nut!!! it will fold the fliter lid in on itself and spirol the wavey ridges running out from the nut. this leads to poor sealing and dirt getting sucked into the motor. you're hood clearence is another issue, the filter lid needs a couple inches of room to get air from. a drop base will do you some good. other than that, you can get different color filter oil to change things up under the hood every noe and then. Brian

 

[Robin7TFour]

Hello, i have been using k&n filters on my motorcycles for years. the biggest factor was the air drawing capabilities. on my bikes they did make a sizable difference in the throttle response,plus the lifetime factor was immense.
at 30-40 a piece for a factory bike filter they would pay for themselves in a year of riding. a lifetime on a car.....priceless

Robin

 

[Bender]

hood clearence is another issue, the filter lid needs a couple inches of room to get air from

I have a K&N on mine and I guess the filter was to big for it and the filter touched the hood and caused the paint to crack? Can any one tell me what size I should get? Someone told me if I get another size the bolt will be to long and I will have to cut it.

 

[AKRAY4PLAY]

Bender,
you should be able to get away with a three inch filter on a drop base. what exactly do you have for a hood, carb, intake and filter right now?? i have seen several cars that the retainer bolt is to long and it flexes the fiberglass beyond the paint's limits, resulting in a crack. i even saw one guy punch a hole through the hood. hood would not latch with new intake, so he made it. real dumb but funny to watch since we told it would happen. i little info on your set-up will help a bunch. Brian

 

[1978L48jafo]

Chris,
I have K&N filters on all of my cars, helps with mileage as well as performance. They really don't need serviced very often.
John

 

[WayneLBurnham]

I have the K&N Xtreme thing with 14x3" on an AFB

Keep in mind some of the stock filters are barely rated at 500 cfm perfectly clean. Your carb or throttle body is rated at more than that. Just like a free flowing exhaust, you want as little restriction as possible in the air flow.

I run low pressure car wash water back through it occassionally - haven't re- oiled it yet as it's still pretty well oiled. You don't have to get silly on the maintenance. Their (and the competing two or three similar designs) maintenance routine is REAL popular - with THEM! They would REALLY like it if you bought LOTS of not that cheap consummable supplies that cost them very little to make.

I am very concerned with where I get my air from - I am pretty certain is is straight off/through the radiator. I have an oversized sort-of L88 knock off hood. I can see nothing to prevent 200 degree air from being the main source of intake air. Compared to 100 degree air, this is an immense difference, like a reverse intercooler. Air density is down and therefore so is power, engine heat is increased and the hotter mixture puts you closer to detonation - enough to make a difference if you were close due to higher cylinder pressure or ignition mods or cheap (or contaminated) fuel.

For over a year, I have been intending to build a two piece air box for the puppy that encloses the whole breather when the hood closes and draws air only from the rear of the scoop, as nature no doubt intended.