Sipie popped over and fitted an ITG to my car in place of the standard paper filter. It certainly seems to be a little smoother and perhaps a little more urgent. We are going to leave it in for a week and see what I think but the whole ITG = messed up Maf = blown engine is playing at the back of my mind. Who thinks ITG's are safe and who doesn't. For the record it wasn't dripping in gunk but if you ran your finger over either side (especially the air-in side) it would be greasy.

Opinions welcome

 

my opinion,

it's not worth the risk especially without a knocklink to try and catch,hopefully,the start of a problem before the real damage happens

JB ran one for ages and it was thick with gunk but I still do not trust them.

 

As you are in doubt, same as me by the way .... and for sure there will be people that they are fine and others that they are not, will you be 100% convinced either way whatever anybody says .... why take the chance unless YOU are confident they won't damage the MAF ... what are the benefits? ... not going to notice a power increase, so i guess just some induction noise ... is this worth the risk?

LB4

 

had mine in for over a year on my MY99 - no probs at all. Just remember to every so often give it a clean...

 

Never had a problem in over 100k km's with ITG panel's

Richard

 

Hmmmmm, unless I feel it transforms the car I'll probably take it out just to be sure. It sucks the way that opinion is so divided on here

 

Had the same dilemma myself. Visited Power Engineering and spoke to Merv, he screwed his nose up at an ITG. I drove off with a K&N and peace of mind.

 

I thought K&N filters were supposed to be even worse

 

15k on mine so far, touch wood

 

Short answer:

. all MY99/00 MAFs die, view them as consumables
. they die in other cars (VAG, BMW) as well (same sensor)
. never really proven that ITG or K&N panel filters have a big influence on this (if at all)
. vibrations possibly kills MAFs quicker (as with some aftermarket induction cone filters)
. there is virtually no difference (measured with a manometer) between an OEM filter and aftermarket filters when they are new
. there will be a difference after say 5000 miles
. the difference between no filter at all and a panel filter accounts only for a very very minor percentage of the total pressure drop in a standard induction system (like 5 %)
. Prodrive (and other companies) warn that the only filter they found to be safe with the Impreza MY99/00 is the OEM paper filter, due to filtration quality mainly
. it has been measured (fact) that most aftermarket filters don't filter out enough silica (which can be then found in oil samples)

It's not because this is drivetrain that we all have the same opinion, but my advice would be to stick to OEM and change that regularly when it gunks up.

 

I had an ITG in a MY99 and no.2 piston went bang, i'm not saying it was due to the filter but the MAF had failed causing the cylinder to run lean. Since then i have ran 30K miles on a standard paper filter with no probs.......i still have the ITG if you want it!!

 

And I know of a company that put 3 new engines in a P1, all lost to MAF failure, all on the standard filter.

 

What's the problem with K&N panels filters then?

 

Are they not oily - hence contamination risk?

 

Don't think so. I've certainly never heard that and mine was dry'sabone when we put it in.

 

I've still not seen a problem reported on here with a K&N panel filter. Plenty of doubters with ITG though, RAMAIR not nice either IMHO.

Theo, If there is next to no pressure drop (5%) then why do inlet pipes collapse under boost? BTW I agree with most of your arguement except the CFM on K&N vs OEM when new as I understand that the K&N is better marginally when new and a lot better when dirty, the filtration is better too.

I have used K&N on many other cars without a problem although I don't use it on the scoob.

F

 

Floyd, the 5 % is the percentage of the *total* pressure drop. The resonator might be 30 %, MAF sensor, inlet pipe shape etc all contribute to the total pressure drop in a typical OEM induction tract measured from the intake point (front of bonnet) to just before the turbo inlet.

Say there is a difference of 20 % between K&N and OEM (just a number), than the pressure drop would be only 1 % less of the total. Even at 50 % (don't think it is) it would only be 2.5 % less.

There's a very good article about this on Autospeed, with also lets you measure it (with a self made manometer if needed) very easily. Don't have the link handy, but search for pressure drop

Not sure why people continue to doubt that the MAF goes with standard filters as well They do, fact, not opinion.

 

lets not forget the added problem of water or water vapour ingestion by ANY type of pod filter,which in turn results in corrosion of the very sensitive my99-00 bosch hot film sensor.
i fitted an apexi power intake which is the only "aprooved"pod by respectable jap tuner "jun" and althought it was completely dry and vibration safe it stuffed up my afm,after driving in lots of rain water for 3 months.
i was lucky that the afm read more air than it was supposed to resulting in extremely rich mixture.
mind u that the afm was not blown so it would not come up in deltadash-select monitor etc.
it was covered with slush and dried out dirty water thought...

 

There are lots of issues - common sense sorts most of them.

There are two MAF issues to consider when playing with filters; vibration and contamination.

Vibration kills MAF's. Contamination makes them under read (v.v.v.bad). Contamination can only kill a MAF if filtration is so poor that rocks are whacking against it (exageration).

Vibration is only an issue with aftermarket pods (as I found to my expense ). The phase 2 MAF's are pretty fragile.

The K&N's (pods and panels) + any other oiled filter are generally fine from new - problem only comes when/if you clean and re-oil it, er, enthusiastically. Contamination follows.

ITG's are not oil based, they use a green snot like substance. You *will* see some of this snot dribble out of the filter in the first few weeks after new. But this is gravity driven, not airflow related, and drops down the dirty side of the filter into the airbox. It is, IMHO, the safest aftermarket panel to fit.

However, you'd only want to change the OE panel if you've removed you're resonator to improve throttle response (....) - without the resonator sticks, insects and small animals have a habit of being sucked in, which the paper filter may not be able to handle.

And certainly not if you're also sucking in water or damp air (a real risk if you've no resonator - although different people would rate it at different levels of *danger* ).

I've run with a K&N pod for the last 6-9 months or so, but will soon be refitting my standard airbox (with modified intake path) - it will house my third ITG panel (they aren't cleanable - chuck 'em away after use).

Pete - do I get a discount now?

Richard

 

Thanks for that in depth explanation drowser

 

I give up.

 

Are my98 mafs more reliable/how much are they,as i may replace it to be safe if there's a lingering risk?

 

I'll gladly take any ITG panel filters o9ff your hands if it will make you sleep better

Serious.. I have had an ITG for about 35,000miles and over a year and it need changing now... on an older car admittedly but I have removed the whole intake and no contamination..

JGM

 

Theo, I have a manometer so I'll measure it!

As David Soul once said "don't give up on me baby" or something like that.

F

 

Floyd (or should I say "Starsky") LOL

You use that manometer

Don't give up on us, gawd, that was one silly song

 

If you want "blue glue" in the air box and subsequently in the mass sensor use ITG.
The best panel filter without a doubt is a K&N one

 

Dowser is my hero, Dowser is my hero la la la la OI la la la la

The first time in ages that I have seen a reasoned response to this ongoing debate.
I have run ITG's for nearly 45,000 miles and seriously, i have not had a single problem. Now as was already mentioned, MAF's are/could be consumables like tyres, batteries etc. It seems that they WILL fail eventually but to automatically say it's because of the ITG is a bit well, off the cuff!
Vibration and Contamination seem to be the two main problems but what about good old "it's broke!?" or unfortunatley your car has a friday afternoon MAF in it.

Nice one Dowser A joy to read

Mikey

Also Pete Croney for pointing out quite graphically that MAF's still fail with the OE filter in place.

 

Regarding goo in the air box... it's actually green not blue and it is ONLY on the unfiltered side!! just proves it is doing a good job of clining onto crap in the air as you can see what it uses to do so etc..

Funny but if it was the goo that was causing the MAF failures it would be obvious would it not?? MAF covered in goo..

JGM

 

Anyone got any experience of HKS filters? I just fitted one this afternoon. Now sounds like a missile launcher every time you change gear. J

 

Hmmm, describe the sound The ITG makes no difference to sound