: Replacement Air Filter

12-25-06, 12:27 PM
What is the best air filter for a North*. I've read ACDleco is best for this application but was wondering if something like an AIRHOG would be better. I've heard the ACDelco will collect more dirt but flow less air and a performance filter will flow more air but trap less dirt. This filter will be for a 96 STS.

12-25-06, 12:58 PM
AC Delco is best. The Air-hog and K&N may be capable of a higher volume of airflow, but the N* isn't going to suck enough to air make it worthwhile. just stick with the factory filter.

12-25-06, 03:19 PM
:sneaky: Danbuc's correct. And.....whatever way you go, don't install an oil-wetted aftermarket filter. That's the surefire way to mess up the MAF/IT and throttlebody circuits. The PCV system does enough to screw up the throttlebody cleanliness without raw oil mist ahead of that. DO the 30 kMi. throttlebody cleaning. The best filter is a clean filter, regardless of the brand on the box. Heck, at 6.95 a pop, you can change it every year or 10 kMi. and stay 'way ahead of the game........besides, if you get into the airbox every year, you'll keep that clean, too. Find the volume formula in a hot rod or car craft mag and calculate how much AIR a f.i. 279 cu.in. engine REALLY needs at 6250 RPM to balance 0" of manifold vacuum. You won't believe that (carbureted) a 585 cfm Holley would be too big. (Same carb as that on a '65 Chevelle / Corvette 327 c.i./350 hp 4-speed.)

12-26-06, 01:35 PM
Well, I use AC-Delco. Haven't had any problems. Personally, I think that any OE Style replacement will fit the bill, but have been use AC for a while, so thats what I'm stuck on.

12-27-06, 02:16 PM
I use a oem replacement (some other brand) in the Eldo. Changed it in the summer. Was kinda hard to do though...

12-31-06, 05:17 AM
As an engine builder/tuner I do disagree on the part about the oiled K&N filters as I have seen independant studies on thier use and MAFcontamination. And guess what if it was properly oild(ie not dripping wet) and evn after owner serviced the amount of oil in the airr tested wasnt enough to damage the MAF. And after helping build Maf'ed cars FI setups I have in only seen one with a contaminated sensor but it was paper air filter "fuzz" on the sensor wire.
I actually see several MAFs made unuseable becasue of air filter paper contamination.
Now I have seen a couple of companies that make a filter sock (kind of like a bag or wrap) for the filters and if you think the filter may release the oil into the air path.Oh and i have only replaced about half a dozen IAT sensors in my life time.
But as for Fram I hate them thier filters are restrictive and personally I dont like them. I had to run one on a engine gettitng dynoed as i had left all my AC filters at home. SO we asked shop where dyno was and if we could buy some filters and oil and fresh engine lost 14 hp by spinning the new one on.
so we went to local Kmart and bought some frams and delco filters and some oil and sure enough we saw a drop. nuff said

12-31-06, 09:16 AM
What is the best air filter for a North*. I've read ACDleco is best for this application but was wondering if something like an AIRHOG would be better. I've heard the ACDelco will collect more dirt but flow less air and a performance filter will flow more air but trap less dirt. This filter will be for a 96 STS.

There was a filter restriction comparison done between many different air filters. They were tested for restriction, and how effectively they removed particulates. IIRC the best all around filter for lowest restriction and highest filtering was a WIX brand. Maybe someone else can find the link, I can't seem to.

12-31-06, 10:36 AM
:confused: MonzaRacer..... ('64 Corvair Monza or a McLarenElvaChevy 327 ??) If you have access to a chassis dyno, it would be most informative if you would take an OBD-II N*VIN 9 (L37) vehicle and run it between 2,000 to 6,350 shift points with: 1. Stock air filter (AC), 2. NO air filter, and 3. An aftermarket oil-wetted CAI setup. The comparisons of (F)WHP obtained would be food for thought.

12-31-06, 11:43 AM
And don't forget the surface area,
Although a paper filter may be somewhat restrictive, this is overcome by increasing the surface area of the filter,thus allowing more air to pass through,
Delco air filters have more than enough surface area to allow as much air as the N* requires.


12-31-06, 11:47 AM
^^ Good point! :thumbsup:

12-31-06, 08:59 PM
I thought we had a couple guys run dyno's an lose power using the K&N filter on the STS.

In any event I used a Purolator that last time I changed my air filter, besides being a pain in the butt to get the airbox to close from the different edging, its worked good thus far.

12-31-06, 09:33 PM
I have ran several different brands of filters on a dynoed 355 and we got the best runs from the 14x3 K7N over several paper filters. I did like the yellow paper Wix/NAPA filter for power production. Purolater from Advance wasnt bad I did try a 4 in AC Delco from a 6.2/6.5 and it did fine.
Now if you get a K&N that drops power it may have been over oiled and I have seen them come out of the box that way. I also use Autostar oiled filters with good luck.
If someone lost power then they may have upset the flow characteristics of thre air intake assembly. I know a fella who swapped out an intake because it was cracked and lost air flow till he swapped air cleaners,both had 3 in K&N's and it wasthe metal part that didnt like the change.
another thing that can happen whith free flowing air cleaners is that the computer needs to adjust the engine for proper running, I remember reading where a fella had a turbo regal and went to a cone K&N and it ran like crap(but he had nothing to put back on as he was 400 mile from home) so he left it on but drove home but as he drove it it started running better and he was going by a track about 100 mile from home so he stopped in to see if it was open to street cars and he raced it on street tires and strange track and it picked up 6 tenths over his best time and when he got home it ran 5 tenths better at home track. He left home for a week and after coming back home from not driving it he drove it and then it came to him that his car probably had to adjust to the extra air flow. Remember this was older GM computer and it is true that they usually worked better after driving with new chips unlike the newer cars with fast computers but I still bet that it has some small part in the loss of power.
Oh well to each there own if you like paper use it if you like K&N use it. Thats why there are tons of parts companies.

12-31-06, 10:18 PM
I was speaking specific to cadillacs. The forum search should turn up intresting things what the board members have found with K&N

01-05-07, 02:13 PM
AC or NAPA Gold, a.k.a. Wix.