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View Full Version : BavAuto cold air intake vs. K&N filter



andyman32
10-20-2004, 07:21 PM
Is a cold air intake worth it for $170 from BavAuto? Or should I just get a K&N filter? Or could I just make my own cold air intake?

Or... none of the above?

What do you guys think?

632 Regal
10-20-2004, 07:35 PM
stock works good

the stock filter/air chamber has been designed for your engine/vehicle exclusivly. Even the airbox between your 540 and my 530 are different so that says something about the thought that went into this. If you go with a K&N you will allow more dirt into your engine, making 300K+ miles a bit tougher.

Also when you retrofit most of the time you eliminate the "cold air" intake and actually hurt performance and mileage with "hot" air entering the intake syste.

So, to answer your question I cant. I can just post an "oppinion" and allow you to do your own research. Personally I wouldnt bother.

In the days of old, carburetored vehicles with restrictive intake systems there was gain even by flipping the air cleaner lid upside down, more so if you put a hood scoop and even more if you sealed the scoop to cold air.

winfred
10-20-2004, 08:30 PM
the "stock" k&n's for some ****ed up reason are usually pleeted in the wrong direction and or only about 1/2 the depth of the paper's pleets and therefore have less surface area then a paper replacement, less surface = more suck per sq inch + the open gause of the k&n = more dirt ingested, that said i have a "stock" k&n on my e30 (haven't finalized induction plans to build a cold air) and a cone on the 535 with my own psudo cold air set up, the cone has a lot more area and cuts down on the vacuum effect, or something. the po if my 535 just had the cone hanging off of the afm sucking manifold and radiator air with no shield and probably gave up 10 hp, i make no clames on my set up but it seems to do something
http://members.cox.net/wdixon27/535%20r%20motor
http://members.cox.net/wdixon27/540%20radiator

andyman32
10-20-2004, 08:43 PM
Wow winfred, the 535 has a much longer intake than the 540. Here's a good pic:

http://www.andywhalen.com/images/car/DCP_1229.JPG

It wouldn't save me much hose length; basically, if I did a cold-air intake, I would just take out the airbox and replace it with a cone filter. I guess that's not really worth it.

winfred
10-20-2004, 08:55 PM
the regular 535 air box starts where the chrome tube is, but it is a big filter that comes on em, i like the long tube that gets the filter close to the front end and away from heat (intercooler tube scavaged from a long dead 630 csi turbo), i am going to insulate it one day, at 3500-4000k rpm it makes a good roar when the motor comes on the cam, i was thinking about playing with the length of the tube but would need a dyno to confirm gains or losses

rockyfeller
10-20-2004, 11:33 PM
I have a BavAuto K&N airfilter w/heatshield...as for performance, it'll only make you feel like you're going faster/more power because of an addicitve new found growl you'll hear on hard acceleration. The old filter is not restrictive of air, just sound. It was engineered to be quiet. So if you'd like a sporty sound it'll do, then again if it's sound you want, a quality exhaust system will do you better. And you won't really get real numbers in terms of performance. If that's what you want an EAT chip will do 10000x more for $170. I am happy with my cone filter, but I'll say the "heat shield" is completely useless. It just makes it look good. It gets damn hot under that hood, and I don't think a metal shield is gonna do much....it dosen't exactly reflect the heat...it heats up itself and heat radiates right through it. There's a pricey proper cold air intake made for the E36/E39 but no one makes one for us yet. Several people have made some home made ones, but it's a lot of work. Still I don't think the gain would be much. I don't believe the K&N will let THAT much more dirt in...I've seen a site about that, I think it's exaggerated. The closed K&N filtercharger that fits in the stock box is a waste of money, don't bother. So do I regret spending $170? Nope, I'm defintely happy but I didn't expect too much.

andyman32
10-21-2004, 07:41 AM
Thanks rockyfeller. I'll pass on the air filter idea. I already have an EAT ultrachip in the car.

ryan roopnarine
10-21-2004, 09:00 AM
.......on sean and johan's site, there's a "note" in the maf section about concerns related to the k+n oil hitting the MAF and making it go out of spec. i don't know how accurate it is.

spitfire
10-22-2004, 08:51 AM
My 95 540/6 was purchased with a K&N filter already installed, with no heat shield. I've always wondered the wisdom of this set up with all the hot air under the hood. Unfortunatly the original plumbing is gone. Does anyone have the original plumbing and air box hanging around? If so, what's your price. Cheers spitfire

632 Regal
10-22-2004, 09:53 AM
My 95 540/6 was purchased with a K&N filter already installed, with no heat shield. I've always wondered the wisdom of this set up with all the hot air under the hood. Unfortunatly the original plumbing is gone. Does anyone have the original plumbing and air box hanging around? If so, what's your price. Cheers spitfire