How much power can a cheap air filter rob?

[PL]

83rwkw.

Yeah, I was surprised too. Car in question was a Datto 910 with S15 SR20. Owner had just fitted a TD06SL2-20G, ext WG, Poncams, 850cc injectors and HPX AFM in a 3" tube.

I ran it up and started feeling my way around at low boost. Seemed a little weird but I forged ahead. Once I'd got things beaten into some sort of shape I tried turning boost up. Couldn't get any more boost! 10psi was it.

Hmmm. After much messing about with a very hot WG the offending air filter was spotted. It was collapsing any time the engine came on boost. Pulled the filter off and the first pull it woke up and started to deliver like it should! Slipped on an old K&N style filter and it made the same power. All good.

Here's a dyno graph showing a pull before and after removing air filter. No other changes.

SR20_TD06_filter_change.jpg

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Now, the guy only buys good stuff and paid $90 for the air filter. A Jap name brand item. I can only imagine that it was a fake. I have no proof either way though.

Apexi collapse.JPG

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Apexi.jpg

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Anyone else seen this happen?

PL

[unex]

something like this?
http://www.youtube.com/watch?v=fwLySsnN ... ture=share

[Torque]

Hmmm,

That air filter is not supposed to be 'cheap' by trade.

Could it be that this filter got wet once and then the turbo vacuum made it collapse?

What size (diameter) was the filter?

Another option would be that this filter is a counterfeit product?
(Though judging from the pictures it looks genuine)

http://www.zerotohundred.com/newforums/ ... arket.html

[Fast Guy]

That's the same filter I have on my Gtir. Mine cost me about £120 several years ago, so probably nearer $240 back then. I'm guessing it could be fake at that price (or I got ripped off )

[Torque]

I just recently installed this filter as well.
Will have it under scrutiny for a while.

£120 sounds like a lot .. was it just for the filter?

[Fast Guy]

Filter and mounting brackets.

[skylinegtrhr]

those kits are really expensive but only filter is not and You can always make DIY adapter and bracket

http://www.rhdjapan.com/apexi-power-int ... ilter-9998

I never have problems with Apexi, we use only them and if budget is big ARC box, I would return filter to Apexi for inspection and replacement.

[PL]

Sorry, I uploaded the wrong graph. All fixed - now you can see the boost and power difference.

Yeah, I've always seen Apexi as good stuff, so I can only assume this was a fake. Worth keeping an eye out.

I have no reason to believe that it got wet an any stage. It looked perfect, the owner tends to stick with quality parts and look after them and I personally know the guy who put it all together - he does a great job. So I'm back to the theory that it's a fake.

http://www.youtube.com/watch?v=44V4n6ARSok

PL

[supersayianjim]

wow, who knew, seems it's missing the metal mesh that should be outside of the filter to keep this from happening!!