What can I expect to see from installing a K&N Free Flow Air Filter?

Higher Gas Mileage? how much more?

Better performance? how noticeable?

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BlueCat
87 Fiero Sport Coupe
Resurrection started 06/2002

quote Originally posted by BlueCat: What can I expect to see from installing a K&N Free Flow Air Filter?

Less money in your wallet.

Well you wont really see any performance increase unless your paper one is in poor condition, you should see a bit better gas milage though. The big benifit from a K&N is that you can clean it as often as you like.

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David hotrodfiero@shaw.ca
85GT 2.9 4spd

I put a K&N on my Trans Am.. The 5.7 Liter engine sucks almost twice the air the 2.8 does.. So it should have been twice as effective. Maybe it did do something, but I never noticed it..

The nice thing is like Captain Fiero says. You can keep it clean all the time. It is a lifetime filter. I wash it and oil mine every spring when I put the car on the road.

I don't plan on getting one for the 2.5 in my coupe...

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1988 Fiero Coupe 2.5L
1990 Trans Am GTA 5.7L

It does flow air much better....but you'll never FEEL the diff. The best thing is you'll virtually never have to buy another air filter again because they are washable.

Phil

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GTDude
OVER 25 years GM experience

Dyno results of a K&N on a stock V6, 4spd... worth it? yes casue you'll never have to replace it... the HP?TQ improvment is just a little added bonus.

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Anyone know where the K&N air filter is on the top-fueler they used to show in the commericals on TV?

Other than not buying replacements, I wouldn't expect much gain. Also, add in the price of the cleaning solution and oil. I'm not sure the cost gain is all that much.

I clean mine with 409 andand a garden hose with a nozzle, then oil it with auto trans fluid. We all used to use them on dirt bikes, Really a good product.
BTW, how much longer will paper filters be available for these cars? As far as I know, this size is not used in any other car... A lifetime filter may be a good idea for that reason alone.

Think of the K&N air filter as a durability enhancement, rather than a performance enhancement.

The oil-filled cloth filter will more effectively remove particles from the air than a paper filter. This translates into less dirt in your engine, which means less wear and tear on engine parts.

The K&N filter will also outlast your car. No need to buy a new filter every 4-6 months at $8-$10 a pop. Pay $30 once and that's it. Well, besides a bottle of degreaser and a quart of tranny oil once a year, assuming you clean and re-oil the filter every 3 months. Over the course of about 4-5 years, the filter will pay for itself. If you plan on keeping your car that long, then it's a wise purchase.

Sounds solid. I like the point about not having to worry about tracking down a hard to find filter.

Will the same thing happen for the oil filter? Or is this a more common size/standard?

And if it will keep the engine cleaner, that is a big plus.

Thanks for the response!

FWIW, the AC Delco air filter for the V6 (A925C) was used on quite a few GM vehicles including everything from a 1985 Firebird V8 (5.0L 305cid) to a 1994 Cavalier Z24 V6 (3.1L 189cid).

The L4 air filter (A913C) was used on everything from a 1982 Phoenix L4 to a 1993 S10 L4.

Above from the online AC Delco Parts Catalog:
http://www.acdelco.com/html/catalog/index.htm

[This message has been edited by ct (edited 07-22-2002).]

You can really hear the motor with a K&N filter,but the .025 holes between the strands of fiber really makes me wonder how effective these things are at filtering volumes of air.
They say 5 microns,but...
Never thought too much about it,but when I took the one off the Lexu$ the other day and saw the openings in the filter,I hucked it off to the side until I can decide whether it should go back on or not.An oem paper one works alright,and I don't want to work on that motor anytime soon either.
Some guy over on the Volvo forum has access to an electron microscope and tested some of the residue found on his airflow meter after running a K&N;the results weren't good,with oxides of silica,some other elements too showing in large particle form,but he didn't test the original paper filter in the same way,so who knows for sure.

I think the biggest problem concerning the stock 2.8 fiero air induction is the design of the filter canister. This design has been proven to be one of the most horrible performing setups available because the incoming air has to change directions many times before entering the intake air tube that connects it to the throttle body. Because of this, I agree that the installation of a K&N filter will show little or no gain compaired to stock.

My friend used to have a 90 Grand Prix with a 2.8L MFI engine that used a different filter setup than the Fiero's 2.8 that consisted of a box with a flat element filter instead of a canister. After he swaped out a new paper element in favor of a K&N, he experienced an increase in power large enough to enable first gear burn outs which were not previously possible before the filter change.

I will agree that the canister shape filter has more filtration area than the flat one used by his W-body. However, I think this canister design advantage is negated by the way the air has to flow thru the unit resulting in large amounts of turbulance.

My fiero utilizes an airbox from a '94 Regal that had a 3800 in it. It is very similar to the typical W-body airbox except where the inlet tube connects to the top of the box. Space restraints forced me to use this "lesser" design. Still, the air enters the bottom corner of the box, passes straight thru the flat element filter, then exits straight out the outlet. (I too noticed a significant increase using the K&N as opposed to the paper; of course, I have a bigger motor than a 2.8)

If you desire all-out flow capacity, discard the airbox/canister system and strap on a K&N cone filter; much like the ones popular with the import guys. However, this too has its disadvantes.

Just my 2 cents.

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1987 Pontiac Fiero Coupe #18,838
3800 Series II SFI
4T60-E Trans
3.33 Final Drive

1987 Pontiac GTA
5.7L SuperRam MPFI
4L60-E Trans
3.73 SRD

http://dtcc.cz28.com

[This message has been edited by SubZero350 (edited 07-22-2002).]

Neither Ferrari or Judd allow K&N filters to be used with their racing or street engines. Long thread about this is Fiero Digest #1204 from last week. I still have it and can send it to anyone. Very factual and informative.
Rick

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So, what was the gist of the thread? Good or Bad?

How could I use a cone filter?

What are the negs?

quote Originally posted by SubZero350: This design has been proven to be one of the most horrible performing setups available because the incoming air has to change directions many times before entering the intake air tube that connects it to the throttle body. Because of this, I agree that the installation of a K&N filter will show little or no gain compaired to stock.

Actually its one of the best. Ask anyone. There was even a thread on fiero-list@fiero.org mailing list about a book that tested it. The reomved the stock air intake and found no significant gain in HP. I took out my water restrictor the free up the flow a lot and replaced it with just a strait peice of exhaust tubing, but that doesnt even really improve the hp much at all. Pontiac engineers did a pretty good job.

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--Adam--
1987 Blue GT 5-speed
IM AOL: GTFiero

quote Originally posted by GTFiero1: Actually its one of the best. Ask anyone. There was even a thread on fiero-list@fiero.org mailing list about a book that tested it. The reomved the stock air intake and found no significant gain in HP. I took out my water restrictor the free up the flow a lot and replaced it with just a strait peice of exhaust tubing, but that doesnt even really improve the hp much at all. Pontiac engineers did a pretty good job.

No offense, but I had that same canister filter setup on my 87 GTA and it was the worst thing I have tried. Of course, I tried the usual tricks of removing the restrictive pieces in the air stream but it didn't seem to help much. I narrowed it down to the canister and replaced the whole unit with the aforementioned W-body air box. This was a huge improvement over the fiero-style canister even though it had a K&N. I am currently running a cone filter element because of my CAI design.

Even though this was proof enough to me that my 5.7L wanted more air than what the canister could effectively flow, I am sure that a 2.8L could benefit as well. I would like to see someone who has access to a flow bench to perform some tests and prove us all right or wrong on what's the best setup.

PS: nice diagrams, but I would suggest that you make an adjustment in where the air flows thru the filter...in that the air doesn't just go thru one side of the filter but all around; which i believe causes turbulance that can rob power. Just my opinion.

(If the canister design was so good, why do all the GN, T-type, and Turbo Regal guys get rid of theirs as a first mod?)

[This message has been edited by SubZero350 (edited 07-25-2002).]

Does anybody know what the recommended way to clean your K&N filter is?

subzero350 ... the canister design on the two cars is totally different. Now I am not saying that you are not entitled to your opinion and I'm not saying that your subjective evaluation is not "right for you". And I would encourage you to make whatever legal and safe changes you think is appropriate on your car.

However, your assertion that the design is flawed was a subjective evaluation. There is not a proven improvement (dyno numbers) on any of the modifications that are so popular on the air intake system of the Fiero. In fact, all the tests and evaluations done so far have results that prove the Pontiac engineers did do a very good job of designing an effective intake in a very difficult position with the materials at hand.

That said: Have fun with your car.

$0.02

I replaced the most expensive FRAM air filter, with the K&N air filter in my 2.5 Fiero. I drove half a tank off the car and got 3 more MPG. I didn't have to mash down the pedal as much, especially at high speeds.

But, the guy at NAPA says that I might as well not use an air filter if I am going to use a K&N. He says that they are cheap and just simply don't clean the air as much. Which means that the longevity of my engine is going to suffer.

Is this accurate? Or As long as I keep the thing oiled, will it filter as much from the air as a standard air filter?

Well it's better than no filter,it will catch the bugs and larger pieces of sand/dust that get in there.

quote Originally posted by Tryxalon: the canister design on the two cars is totally different. Now I am not saying that you are not entitled to your opinion and I'm not saying that your subjective evaluation is not "right for you". And I would encourage you to make whatever legal and safe changes you think is appropriate on your car. However, your assertion that the design is flawed was a subjective evaluation. There is not a proven improvement (dyno numbers) on any of the modifications that are so popular on the air intake system of the Fiero. In fact, all the tests and evaluations done so far have results that prove the Pontiac engineers did do a very good job of designing an effective intake in a very difficult position with the materials at hand. That said: Have fun with your car.

Thank you for the info but I am afraid you are not entirely accurate with the information you presented concerning the air filter housings:
1. Both the 2.8 fiero and TPI Firebird / Trans Am's use the same part number air filter (you can look this up at autozone.com).
2. The only major difference in the canister design between the two cars is how the air flows thru the unit. In the Firebird, the air flows out of the center of the canister...while in the fiero the air flows into the center of the filter element.
In any case, I still believe this setup does not promote the most free flowing air intake stream that can be attained while using any filter element.

As I stated before, goto turbobuick.com and ask most there who have "fast" cars as to if they believe your air filter setup is the best or not.

Again, no flames intended and I welcome your and any other person's opinion. I have not seen any actual dyno or test data concerning the fiero's stock air filter setup so if you know where I can find this info, please enclose the URL with your next post.

[This message has been edited by SubZero350 (edited 07-25-2002).]

SubZero350

Jeesh, listen to yourself.

You said "2. The only major difference in the canister design between the two cars is how the air flows thru the unit. In the Firebird, the air flows out of the center of the canister...while in the fiero the air flows into the center of the filter element. "

That's pretty freekin major!

I have seen the pages, but don't have the URL's, where CFM tests were done with the stock fiero intake housings in good condition versus NO INTAKE AT ALL. no difference in HP, TQ, mileage, etc.

That means that if your stock fiero intake system is in good working order, there is no way to improve the airflow through it that will help our cars. That, of course, all depends on whether you have a stock car in good operating condition.

The only way you will see any performance increases from changing anything in this air intake system is if one of these conditions exist:
1.) your stock intake is not operating like a stock intake should(bad filter, junk in there, etc.)
2.) you have MODIFIED your engine to need more air.
3.) for some reason (the hand of god) your car is one of those special "from the factory super cars" that for some unknown reason runs better and needs more air. I believe that ??banditbalz?? had one of these mysterious factory cars that could run low 15's stock???? (or someone here was posting unbelievable stock numbers that were proved to be true)

period.

no ifs, ands, or buts.
its simple logic.
except for that "hand of god" stuff. Insurance companies won't touch that one, and neither will I.

[This message has been edited by fierogt88 (edited 07-25-2002).]

quote Originally posted by fierogt88: I believe that ??banditbalz?? had one of these mysterious factory cars that could run low 15's stock???? (or someone here was posting unbelievable stock numbers that were proved to be true)

My low 15 second runs were with the help of a K+N air filter and a Holley scoop. Sooo, not completely stock... Would it be any easier to swallow if I told you I have 180,000km on the original motor? 7 year old plugs? dirty injectors?

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Silver 86 GT
no truck, no trailer, no spray!

I think that driver has a lot to do with it... I ran 16.45 last time, I also spun the wheels like a mo fo... I know I could get mid 15s if I got better tires and some better clutch control.