ABY Airbox filter

[Robatron]

Right,

I will soon be in possession of an ABY airbox to fit to my car. The reason being is that I have heard bad things about the K&N cone filter that I currently have sitting under the bonnet.

What filter is best to use in the airbox? I have heard that various 'panel filters' have been used, one of which is also K&N, but I would be interested to know which filter is best.

I have picked the Airbox up at a reasonable price so if I see no real gains lower down in the revs then it won't be too much effort to change back to the cone filter I currently have fitted.

[Jamo]

OEM filter no BS

[Crawford_S2]

I use K&N panel filter, K&N list the ABY as RS2 though. If you order the S2 one you get 3B!

[Jamo]

Eh? RS2 and ABY = no difference, at least on the standard airboxes

[Jas11n]

Eh? RS2 and ABY = no difference, at least on the standard airboxes

I understand what he means.
If you order an "S2" K&N off K&N parts lists, they send you a 3B sized one. They mistakenly list the ABY as being the same as the 3B (S2 91-95 etc).
You'd need to order an RS2 one as "we" know they are different.
I mailed them the mistake and never got a reply.

[Dpicariello]

I have a K&N panel in mine, it's been there since I bought it.
Lots of people say that the oil from it can build up on the MAF and therefore be a bad choice. However, I've had my MAF out twice in 9 months now (about 5,000miles) and haven't noticed anything.
Just something to bear in mind. If I was in your position I probably would go OEM as Jamo said.

[Fat Audi 80]

OEM for me!

[Jamo]

I understand what he means.
If you order an "S2" K&N off K&N parts lists, they send you a 3B sized one. They mistakenly list the ABY as being the same as the 3B (S2 91-95 etc).
You'd need to order an RS2 one as "we" know they are different.
I mailed them the mistake and never got a reply.

Jas too the rescue once again

[Paulgo]

Interesting as I had a K&N in my 3B airbox but swapped it a couple of months ago for an ABY box (which looks sooo much better than the weird lump of malformed plastic 3B's come with!) but that just had a standard filter in and Ive been meaning to get a K&N to replace it as I always thought it was a better option peformance wise (also now know to ask for a RS2 off K&N if I do!!)

[Rusty]

K&N in mine. No MAF problems, clean it every 6 months or so as a matter of course, usually because I've had the overboost protection cut in for whatever reason.

The standard filter must be ok as it's used in the RS2 and can therefore take 315bhp all day long

Nothing wrong with cone filters if you can shield them properly from the hot air off the turbo and get a suitable cold air feed to them. Difficult in an S2 though. I noticed a bit more heat soak (with a cone filter) but mine was mounted directly to the MAF, held in place with cable ties and was shielded with aluminium foil . It was a temporary measure to see if I liked it or if it made a difference. I concluded no to both. The ABY airbox is a lot quieter than a cone filter too, so depends whether you like noise or not.

[HPmuirt]

Stick with OEM as Jamo et al suggested above. If you want more airflow, get an RS2 airbox. I don't know what they flow at, but as already stated; they are certainly fine at 315BHP+

Several tests have clearly shown that whilst some of these 'performance' filters can flow slightly better than the OEM paper elements (typically by no more than 6% - 10% better though), this is VERY quickly lost and soon actually flows worse than OEM

Finally, it has also been shown that the single largest restrictor to airflow in the ABY is the MAF, not the airbox, so changing to an RS2 MAF should help even more than the airbox. I understand that this is due more to the hole size in the gauze than the actual venturi shape of the MAF, but in combination there lies your biggest demon

Cheers n

Si

[Rusty]

You can live life dangerously and remove the gauze. One of mine broke so I left it out...

[pixsaudisex2]

i have also took out the gauze as i figured that anything going down there that is small enough to go through the gauze will cause damage and anything bigger just shouldnt be there ( the gauze also looked like it was going to fall apart any day.)... so in the actual maf is that heat sink looking thing in there for is it to warm up the air flow on cold days or as a heat soke as i was getting tempted to dremel all of this out as i think it would make quite a diffrence... the gauze removal seemed to make no diffrence.

[Robatron]

I noticed a bit more heat soak (with a cone filter) but mine was mounted directly to the MAF, held in place with cable ties and was shielded with aluminium foil .

Mine is attached in the same way minus the cable ties.

Finally, it has also been shown that the single largest restrictor to airflow in the ABY is the MAF, not the airbox, so changing to an RS2 MAF should help even more than the airbox. I understand that this is due more to the hole size in the gauze than the actual venturi shape of the MAF, but in combination there lies your biggest demon
i

Well I actually have a 3b, so is it possible to attach an RS2 MAF without any problems?

Whatever happens I will be taking a leaf out of Mr OEM's book (and everyone else's) and will get the OEM paper filter.

[newsh]

so in the actual maf is that heat sink looking thing in there for is it to warm up the air flow on cold days or as a heat soke as i was getting tempted to dremel all of this out as i think it would make quite a diffrence... the gauze removal seemed to make no diffrence.

I take it you are not having a laugh?

The MAF (Mass Air Flow) sensor measures the amount of air going into the engine so that the right amount of fuel can be injected to get the mixture spot on. It measures the change in resistance of that fine wire in there which is heated by an electical current.
Best not to mess with it.