The definitive "What Air Filter?" discussion thread

[Wompa 0]

Kev: Thanks for the info.. a originalbox is ordered! 8)

[tjw199 0]

Hi,

Where can I get an original filter box from?

I currently have a K&N57i but its a little noisy! Will putting an original box on reduce the noise slightly without reducing performance?

Cheers

Tim

[dukest 0]

yes, is the quick answer.

and do you mean where else can you get one apart from the dealers or 2nd hand from someone on here?

[Jim 2]

Hi,

Where can I get an original filter box from?

I currently have a K&N57i but its a little noisy! Will putting an original box on reduce the noise slightly without reducing performance?

Cheers

Tim

 

In fact most people find when they ditch a big unshielded cone filter like a K&N they actually gain a little power. Keep an eye on the classifieds / breaking threads.. VR6 airboxes come up regularly enough.. in fact PM Alonzo as he had one for sale at Tatton Park this weekend (assuming it hasn't sold) complete with a MAF for £40 which I thought was pretty reasonable :)

[tjw199 0]

Cheers for the advice, its a little noisy to be honest!

I thought someone mentioned that you could still get the original box new, but I can't find one anywhere on the www.

[Jim 2]

Will be a VW part really - not something that GSF, ECP would carry. As said though, a brand new one will be expensive to be honest for a bit of plastic you won't even see just buy a second hand airbox and then go to the dealership for a nice new air filter to put in it :)

[tjw199 0]

Will be a VW part really - not something that GSF, ECP would carry. As said though, a brand new one will be expensive to be honest for a bit of plastic you won't even see just buy a second hand airbox and then go to the dealership for a nice new air filter to put in it :)

 

Thanks Jim, cheers for the advice. :D

[daytona600 0]

How strange. Reading this. I had a cheap induction kit on my VR for 3 years or more and only last week put the original box back for something to do. The improvement in smoothness and power was immediate. It did not sound as nice but I will be keeping the OEM.

[Kevin Bacon 5]

How strange. Reading this. I had a cheap induction kit on my VR for 3 years or more and only last week put the original box back for something to do. The improvement in smoothness and power was immediate. It did not sound as nice but I will be keeping the OEM.

 

Good man :salute:

 

After using assorted cones and BMCs and the like for a goodly number of years , I've also come to the same conclusion that those boffins at VW knew what they were doing with the standard air box arrangements :D Even with a Turbo, the stock airbox gives better results 8)

 

One thing that puzzles me is the swiss cheesing thing tbh, but I can appreciate some folk want more noise.....but it's a £100 airbox, so please people, buy a cheap cone instead if you want noise and protect your box :D

[toyotec 0]

I did a series dyno tests on an ABF 16v engine where the intake system i.e. from filter box to throttle duct was investigated to see if there could be any improvements to minimising pressure drop.

 

In that exercise there was a stablising baseline then the factory airbox was stepped from std system with and w/o panel filter, to pod filter , to modified airbox with and w/o OE/aftermarket filter.

In the end the single one improvment on that airbox was the removal of the lower and upper airhorn + the creation of another hole towards the fender side of the car. This modified airbox produced slightly more torque post 4500rpm to 6800 than the rest of combinations. It may just been very slightly better than the best oiled cone filter( not that you would notice).

The aftermarket panel filter had no performace benfit over the new factory paper element. There was also no benfit or loss to torque running without. The airbox was free, the mods took time but were free and the filter kit was 80Quid. So 80Quid saved.

I use a similar airbox to kevhaywire in my 315PS 16v turbo, with subtle modifications to tweak sound. My VR6 also uses a factory airbox modified for some noise and similar to the 16v AIS study.

We must also understand that testing a vehicle on a dyno with a fan blowing at the engine bay is one thing, but drop the bonnet over a hot engine and the temps do shoot up to

Stick to your the black plastic air boxes. With the right modifications they can be tuned for the best response.

[coullstar 0]

Ive tried a few airbox's but cant get them to fit into the space i have. FPR is in the way.

[toyotec 0]

Ive tried a few airbox's but cant get them to fit into the space i have. FPR is in the way.

 

It does not have to be an OE unit if packaging would prohibit. Large surface area cone will also work provided it is properly shielded from engine bay heat. It is the enthusiasts who bin their std filteration thinking that brand x filter kit is "better" without understading why should take note.

[coullstar 0]

So your saying that work you have done indicates that if the filter is properly shielded from the heat it should work ok? So the likes of the BMC is obviously better than an open cone filter but if the air its inducting is still from the warm bay its defeating the purpose of using it. I think thats the accepted idea but its good that someone has actually proof.

[toyotec 0]

So your saying that work you have done indicates that if the filter is properly shielded from the heat it should work ok? So the likes of the BMC is obviously better than an open cone filter but if the air its inducting is still from the warm bay its defeating the purpose of using it. I think thats the accepted idea but its good that someone has actually proof.

[toyotec 0]

So your saying that work you have done indicates that if the filter is properly shielded from the heat it should work ok? So the likes of the BMC is obviously better than an open cone filter but if the air its inducting is still from the warm bay its defeating the purpose of using it. I think thats the accepted idea but its good that someone has actually proof.

 

Yes. If you have an issue with packaging and the standard unit is not suitable to be used or modified, then the option you spoke about, once it can flow and does not induce heat soak into the charge, would be a good option.

[ANDREW 30 0]

I'm loving the Gruppe M induction kit i've got fitted to mine at the minute, i'll be gutted when I have to remove it to have the rotrex charger kit fitted!

[cannon2516 0]

i fitted a bmc the other week and with out the cold air in take pipe, it sounds great when you put your foot down, but nice and subtle when normal driving, twinned with the dub power exhaust it sounds a treat when the foot is to the metal,

 

fitting wise it was straight forward, bought a coupler off ebay for about a fiver and used the supplied jubilie clips to secure it down, (coupler was not supplied with the kit i bought but comes with some kits) comes with a bracket to secure in place to where you see fit, i used a bolt near the suspension bush near the mfa and used the bracket.

 

i cant compare this to anything but im happy with the performance and sounds great, like a dirty great muscle car!

[Kevin Bacon 5]

I did a series dyno tests on an ABF 16v engine where the intake system i.e. from filter box to throttle duct was investigated to see if there could be any improvements to minimising pressure drop.

 

In that exercise there was a stablising baseline then the factory airbox was stepped from std system with and w/o panel filter, to pod filter , to modified airbox with and w/o OE/aftermarket filter.

In the end the single one improvment on that airbox was the removal of the lower and upper airhorn + the creation of another hole towards the fender side of the car. This modified airbox produced slightly more torque post 4500rpm to 6800 than the rest of combinations. It may just been very slightly better than the best oiled cone filter( not that you would notice).

The aftermarket panel filter had no performace benfit over the new factory paper element. There was also no benfit or loss to torque running without. The airbox was free, the mods took time but were free and the filter kit was 80Quid. So 80Quid saved.

I use a similar airbox to kevhaywire in my 315PS 16v turbo, with subtle modifications to tweak sound. My VR6 also uses a factory airbox modified for some noise and similar to the 16v AIS study.

We must also understand that testing a vehicle on a dyno with a fan blowing at the engine bay is one thing, but drop the bonnet over a hot engine and the temps do shoot up to

Stick to your the black plastic air boxes. With the right modifications they can be tuned for the best response.

 

Good response, I missed this somehow. Good to see someone putting things to the test scientifically. It's exactly what the OEs do but mere mortals like us don't have access to their expensive bench dynos to prove our work.

 

Interesting about your 4500rpm torque improvments after removal of the Helmholtz resonators. How did you find the torque below 4500rpm?

 

I went from a BMC to the factory air box and did the same thing, except the extra hole. It felt noticably flat off boost and the induction noise / turbo whistle quickly got on my nerves. I then bought a new air box and left it completely standard and it was a different car on and off boost. So much more responsive everywhere in the range and the noise levels are perfect. You wouldn't even know it was turbocharged. Perfect for a daily car not wanting to attract attention to itself.

 

I am interested in the extra hole idea though, but I don't want to lose the Helmholtz tuning, so I might remove a section that can be easily put back again, then feed the hole with pressurised air from the front of the car. I don't normally buy into 'Ramair' but with turbos, the airbox quicky empties when you crack the throttle wide open and pressurised air feeds keep it filled, which will reduce intake reversion. I think also to help this, retuned resonators for boost work would help enormously. Compare a normally aspirated resonator to a boosted resonator (say from a 1.8T air box) and the latter is much shorter, bigger bore and has a bigger bell mouth.

 

As for filters, we all try the oiled cotton but then you come to realise that if you unpleated a stock filter and a K&N filter and laid them side by side, the stock filter has MASSIVELY more filtration area. K&Ns quickly clog up with dust (thanks to the oil attracting it in the first place) and you've lost a lot of filtration area within

[Ralphead 0]

When I bought my 1.8 the airbox had had holes hacked in it all over, mostly on the engine side. All kinds of crap was getting in, so I cut some bits of plastic from a broken dustbin lid and gutter glued them over the holes.

I had one of those nice turned alloy air intake horns with a peice of 2" pipe to fit laying about. Whilst the box was out I realised that the warm air intake pipe was the same size so I cut an inch and a bit off the stub on the box that it fits to, hole sawed a hole in the front corner of the box and got the poly pipe out again so create an new stub.

I cut a corresponding hole in the plastic panel next to the rad for the other end and the horn. Fitting the pipe and horn took a little fiddling. A peice of coarse gauze from a 4inch air duct outlet fixed over the horn stops too many moth's and wotnot getting sucked in. Job's a goodun

 

I'll get some photo's up when I can

[Redfox 10]

Hi all,

Running a standard paper filter, then a K&N panelfilter in the box. No extra holes or anything.

Noise is the same, and performance is more or less the same. To be able to use an eventual little bit more airflow in, one needs to have afree exhaust, a camshaft etc.

Then the small things begins to ad up, and become a noticable effect.

 

Anyway I just wanted to say, that I have seen many times a K&N and alike filter oversprayed with oil and therefore reducing power. Another important thing is that oil can find it's way through the induction pipes, to the sensor (blue) before the inletmanifold. If this get's oily, it confuses injection as far as I understood it (G60).

Therefore an extremely well cleaned filter is of paramount importance, and only a very very light oiling is needed.

 

Just my two-pence,

Redfox.

[Snozdog 10]

Hey everyone,

 

I had a quick look through this thread but i couldn't really find what i was looking for so i need a bit of help. I have recently got a 1993 VW Corrado 2.0 16v. We were looking in the engine bay and we've taken out the stock air filter box. Then came the difficulties.

 

I have a BMW E36 and the air filter is in a box, behind the box is the MAF sensor which leads to the fuel management. This makes for easy modification. However on the Corrado the MAF is attached to the top of the air box and the fuel distributer is mechanically attached to it, (also attached to the airbox). Im looking for increased airflow at the moment, or some form of induction kit, but im not too savvy on my Volkswagens. So does this mean that any modifications are either large engineering job, or can it simply not be done.

 

Maybe the only way around this is to cut holes in the filter box, or has anyone found another way to get something a little "different" going?

 

Ash

[Ralphead 0]

Have a read of my cold air feed post on the previous page. It all sounds a bit pikey but you can't really glorify cutting and gluing plastic..

 

I'd imagine your airbox is a bit different to mine due to being efi rather than my k-jet but the principles the same.

 

I'll take some photos tomorrow and try to post them. It may help it make more sense.

[Ralphead 0]

[Abdul 0]

Ralphead, that's a very cool intake baring in mind there's not normally much you can do for valvers!

[Ralphead 0]

Thanks Abdul. It's cheap to do, makes a nice noise as well.