The definitive "What Air Filter?" discussion thread

[CazzaVR 0]

Anyone else think this is a good idea? Topic seems to come up regularly- might be good to have it all in one place. People could post up their experiences (power gains, noise, problems etc) with the various options available, such as:

 

BMC CDA

 

K&N 57i induction kit

 

Stoeve Motorsport induction kit for the 16v

 

Pipercoss Viper

 

K&N Panel filter

 

Carbonio CAI

 

Drilled airbox

 

etc etc

[ADZ_VR6 0]

yeah good shout need a new filter :)

[nemesis360 0]

I ran a Pipercross for a while then a K+N both sound great on a VR and I could tell any difference to be honest

 

Graham

[CazzaVR 0]

I ran a K&N panel filter in all of my valvers. Drilled the airbox (wingside) with the first 2. Sounded great, with a nice growl. No difference power-wise.

 

Used a K&N panel filter on my last 16v and just removed the snorkel. Again, nice growl, but not as loud as the drilled box. Throttle response seemed a little better.

[marcus 0]

What about 'Ramair' air filter - large and less than £100.00 ? Sold my BMC for it too.

[jamminvr6storm 0]

Im looking into a K&N Apollo now.......

 

Ive had (and still use) a 57i, have also tried a cone filter inside a standard airbox. Never used a BMC so i cant comment!

 

Think they are all much of a muchness!!

[chazrad 0]

Loved my Ramair which I had for 6 years...great noise. I had to sell it on when the charger was fitted. Now got a K&N cone fitted down in the bumper, which I can't hear - unsurprisingly!! :D

 

I think air filters are a really subjective thing. Some people want them noisey (me!!) and others like them to be stock quiet (then stay with the standard airbox!!?). The BMC always sounds good - at least when Corozin hoons past me at XXX mph on the motorway in 4th....he's had one for a while. I think I'd probably go for one of those on an N/A VR6 nowadays.

[CazzaVR 0]

Have had a K&N 57i on all my VR6s. Sounded great and the quality of the kit is superb. All the brackets etc fit perfectly.

 

However, as Kev said in the K&N thread, for me the performance felt a little 'flat' when compared with the standard airbox/K&N panel/BMC.

[mariojoshi 1]

I've been told by numerous people that the BMC CDA is extremely good, sounds good and actually keeps the air cool due to it being carbon...

 

I've not really looked into it as yet.. but I'm tempted.....

[Guest]

Had a ramair on for a few months now and it makes one hell of a noise. I am im the market for a BMC CDA however as there is a fitment issue and performance does seem to have dropped. Also It is just a bit too loud, I do feel a bit conspicuous when flooring it off a roundabout and I have scared a few sunday drivers when overtaking them :lol: Wouldn't want to cause an accident :lol:

[Storm Warning 0]

Had a RAM Air, lasted 3 Miles, really didn't like the excessive induction noise, you hardly had to touch the loud pedal for a raw, not my scene. Got a BMC and its very complementary to the VR, not too excessive in my opinion but on full tilt.. oh yes! 8) oh yeh and I think its the only induction kit that stealth reported any noticable improvement on the RR.

[mariojoshi 1]

Absolutely.. and to be fair, it makes sense!

 

VRs generate SO much heat in the engine bay that an open filter would naturally cause a problem.

Stick that filter inside a carbon box which "causes a vortexing effect" (if you believe that bit) and you're onto a winner!

 

Very happy with my BMC also.

[MonkeyVR6 0]

Absolutely.. and to be fair, it makes sense!

 

VRs generate SO much heat in the engine bay that an open filter would naturally cause a problem.

 

Not enough for you to make a difference though.

 

I've got a Pipercross VR6 Induction thingie, nice grumble and sounds great at full-chat. Not too sure if it adds power, not that I've noticed anyway, but seems more responsive, might just be me?!

[CazzaVR 0]

Try swapping back to the original setup to see the difference. When I did that with my K&N kits, the car defo felt a bit quicker/smoother/more purposeful with the standard setup. Just didn't sound as good, although the quiet car is a nice change for a few days :)

[Dogzyboy 0]

Another vote for the BMC CDA here. Fitted mine about 6 months back & love it :D Not too good for the fuel economy though as you have to keep booting it to hear the addictive roar!

 

It's nice and sensible when croozin, but lets out a lovely roar once you get up to about 3.5k revs. Theres no going back for me now!

 

Best thing of all is that the missus hasn't even noticed I've changed it! :lol:

[aks650 0]

weres the best place to buy the bmc air filter? and is it easy to fit?

[Dogzyboy 0]

Stealth & yes. :)

[Jim Bowen 1]

Try swapping back to the original setup to see the difference. When I did that with my K&N kits, the car defo felt a bit quicker/smoother/more purposeful with the standard setup. Just didn't sound as good, although the quiet car is a nice change for a few days :)

 

 

thats what i did, and stuck with the standard setup, i trust VW more than all these universal cone type filters that seems to be the same design for every car.

 

have heard alot about people losing power when mucking about with BMWs factory air induction

[tandino 0]

Standard filter in a drilled airbox works for me.

Drilled on the cold side so not hot air entering.

Best of both worlds - filtration of a proper paper filter and the noise to boot.

[Jim Bowen 1]

i'm still not sure what to get, whether to stick with standard or not,

 

here's some comments i've received on the subject

 

"Cotton-gauze will ALWAYS perform well when new - they're often replacing a shitty used paper filter and a new foam filter is more restrictive than a new cotton-gauze filter (up until approx 500-1,000 miles).

 

A filter should do two things - protect the engine and flow air. A cotton-gauze cannot do both for a long time due to it becoming clogged. With cotton-gauze the only place for dirt to be trapped is on the surface, with a foam filter dirt is trapped throughout the filter, hence it's greatly increased life before cleaning.

A clogged filter is starving the engine of air and you might as well just stick with a paper filter for the amount of good it will be doing.

 

The best design for a fast road car involves getting air from an area of high pressure. The only true way to do this is to extend the air intake out beyond the front of the vehicle but a good alternative is to fit a Viper or CDA, better still, turn it all around and put the filter in an area of high pressure and have an airbox full of clean filtered air - which is what you get with Carbonio/VIS kits.

 

The downside of a Carbonio kit over a Pipercross VIS is that the filter they use (cotton-gauze) isn't suitable for areas of high pressure which are typically areas of increased dirt. K&N even supply pre-filters for their air filters in the US, yet other companies that use their products don't bother! That's engine protection out of the window from the start.

 

There's so much research into air intake design, fitting a universal BMC is ludicrous. You're not a silly Jim so I can't understand why you're falling for it time and time again

 

The VIS kit is such a good solution both for performance, looks and sound."

 

&

 

"Most views are based on what people read on forums and what they've bought, that's not fact. My views are based on tests I've carried out and results I have seen (including independant) whilst under the employment of Pipercross.

Other foam filters (ITG, TrueFlow, Unifilter, etc) are equally as good but they don't make intakes for the VR6.

 

I'd fit the VIS kit without a second thought. I fitted one to a mates VR6 and it was nothing but grins all round."

 

anyone think much of this?

[CazzaVR 0]

Mods - can we sticky this? Seems worthwhile to have it all in one place.

 

3corsameal- some interesting points there. Cotton filters do get clogged over time, but you just give them a good clean and re-oil (lightly). Cleaned my BMC a couple of months ago. Personally, I'd say it has to be a BMC or some sort of CAI like the Carbonio.

[Kevin Bacon 5]

Same old, same old.....about the foam that is :roll:

 

Stickied at your request.

[Jim Bowen 1]

i know cheesewire, its like a never ending debate with no real answers, so i'm not sure whether to spend £160-£200 on something for a bit more noise (although i kinda want that) :lol:

 

from what i understand the pipercross vis kits have a filter that sit nearer the front/bottom of car bumper, but they don't list one for the corrado

[Kevin Bacon 5]

It's all about tangible gains and benefits mate, i.e. real world differences you can feel, see and hear.

Very, very few air filter "kits" offer anything worthwhile other than a nasty racket that sounds chavy at worst, a bit meatier at best.

 

The motor trade has been plying us with horseschitt for donkeys years, with grossly exaggerated claims.

 

OEM paper is the best filtration medium but it clogs quickly. That's why you generally get very large paper filters, it makes up for the lack of flow and the fact they trap more dirt and clog sooner.

 

Paper is designed to be good at filtering because of the conditions road cars have to operate in and OEs have to put reliability before outright pace on their road cars.

 

It is definitely the worst filter in terms of flow, but the cleanest for the engine.

 

Paper is crap when it gets wet, which is why it's in a nicely designed enclosure to keep moisture out.

 

Paper is also crap for turbos unless the airbox is designed properly to stop it collapsing. OEs will have ensured that is the case with their airboxes.

 

Paper is also very cheap to produce and mould into intricate filter shapes. And what is it OEs care about above all else? Minimal outlay, maximum profit :wink:

 

For a standard car and with mild mods, paper in the stock airbox is fine and actually preferable to open cones and these ghastly foam things you see that look like oversize microphone filters.

 

Foam and cotton were developed for race cars, and flow is more important than filtration when the engines are rebuilt / replaced frequently.

 

Cotton stands up to turbos better as it's physically strong. It also copes with water OK and it does filter well and flows well too.

 

Foam I've never seen the point of personally. Paper and cotton stop the dirt in it's tracks instantly and keep it at the filter's barrier. Foam lets dirt inside it. So how can you be sure you are removing 100% of the dirt when cleaning a foam filter when you can't even see half of it? Complete crap imo.

 

Obviously no filter at all presents the best air flow to the engine!

 

And "Ram air" effect is the biggest pile of bollocks ever! Are you ever likely to feel 1psi above atmospheric at 120mph? Nope, you won't :-)

 

Let's not forget that engines draw in what they need. All this forcing it in via "Ram air" is complete nonsense. With turbo engines, that's even more true!

 

So you want to spend £160-£200 on a mod? Well I've shown you that £187.90 cams gives you 26hp and 20lb/ft torque, but you'd rather spend the money on a filter which gives you f'ck all??! :cuckoo: Oh well, it's your money :lol:

[Jim Bowen 1]

very well put indeed. 8)

 

i have always kinda doubted them which is why i'm still using a standard box with paper filter.

 

i think i'll stick with that and forget the aftermarket filter idea again :lol: