Just sharing some photos of the HKS foam mushroom filter that came on my girls t2 from the previous owner. Feel free to share your own pictures and experiences in replies.

No idea how long it was on the car. Bought the car and immediately started a rebuild on it. It's been in my garage since. I just went to do a last minute checklist before I begin to put the accessories back on the keg.

It's a genuine HKS foam mushroom filter.




I just touched it with my finger and the foam literally deteriorated.


I guess I will give her my corksport tid and k&n filter since it's a tad small for my hybrid turbo and I have a powerFC now.


I know we all know the HKS foam mushroom filter has poor filtration and deteriorates. I just wanted to share the photos for non-believers. The filter might work if changed frequently, I'm not sure. But after seeing this... Do you really want to try and see?

 

Those intakes are so overpriced (even with the CARB rating)... People just assume because it's HKS, it has to be good.

 

you're supposed to change the element every 6,000 miles or so, but nobody ever did

 

+1

 

Hk$

 

I have dyno results to show that airflow restriction by the element results in -3 hp loss vs. running no filter on a nonturbo application (this is about 2% in my case). I consider this acceptable, so I never checked it vs. the stock air box, nor did I bother with any other solutions.

 

I have the EXACT same filter. Makes a lot of intake noise on my car. Someone wanna post results vs. stock intake??

 

even if there is a gain(or lost?) it will be so small that you probably never gonna notice it.

don't think anybody will want to go on a dyno and pay the $$$ just to see if there is a different between stock and HKS filter, especially on this 20 yr old car.

just my thought.

 

that filter is probably 10+ years old and has been sitting outside for some/most of that time

 

i have had plenty of dirt bikes with the same type of element sit outside for as many years and they still were pliable and reusable.

HKS uses inferior materials.

hell, you might be able to find a UNI filter replacement that fits some of the HKS pods that will last so much longer.

why is it acceptable to replace the element after only 6k miles? my dirt bike elements virtually last as long as the bikes themselves regardless of the amount of abuse i put them through or heat factor.

i just cleaned a STOCK filter element on my '89 suzuki LT230 quad, still fine.. 22 years old!

 

you cant blame HKS for poor maintenance..
I've run the mushroom filter and eliment on all of my rx7s. I change it, when it starts to show signs of dirtiness, like a slight dark green. Its bright green when new.. look at that thing.. dryrotted and black.. the cage is the same color lol..

 

attribute the end result of the OPs filter due to age and long term exposure to the elements..
you can get the same result from any other air filter element if under the same conditions..
ive had long term use on the same type filters for over two decades on my motorcylces and cars.. a few of which were hks..
none succumbed the way the OPs has... who know whats has spilled onto that filter all these years... and look at the rust on that cage..

 

Don't forget these filters should be oiled with air filter oil so they don't go brittle. My guess is that this filter in question has never been oiled or replaces as prior mentioned. The HKS filter is of an okay standard, but there are better on the market.

 

You can tell it is toast just by the burnt look. The filter is supposed to be a bright green color, and generally it needs to be replaced as soon as it shows any dark spots. As already posted here, HKS recommends replacing them every 6,000 miles.

I have tried the HKS filter for many years and I know a lot of other people who have used them. Sure, I like K&N better, but the HKS filter works just fine when used properly. For those who are filtration *****, the OEM paper type filters tend to filter out more junk than the performance filters.

I have several RX-7 parts that have deteriorated due to age and exposure to the elements, and I do not blame it on Mazda nor do I consider the RX-7 a piece of crap.

If you want to see a truly bad air filter, just order one of those crummy no-name Ebay filters. It will fall apart and get sucked into your engine in a matter of months.

NO! DO NOT RE-OIL AN HKS FILTER!

 

Could have sworn I read you should? Perhaps it wasn't hks? My bad, you seem to be pretty sure about it!

 

That would be K&N. They have to be re-oiled.

 

the HKS has a graph on the box showing that if you don't filter the air it flows more, which is at least honest.

the race car has an AEM filter on it, and the same dirt on the outside of the car is on the inside if the intake pipe = AEM sucks too.

 

HKS filters are "DRY FLOW" and never need to be oiled.

at least that's what my RX-8 HKS Intake said (never installed, long story) and I would say HKS has been using the same kind of material for years.

 

My HKS Honeycomb intake works just fine. No issues for me.

 

Yeah they need to be replaced, looks old.. also there are tons of knock off fake hks foams out there, not saying that is the case here.. Throw a new one in and its good.

who knows, the prior owner could have been spraying it with carb cleaner, or even taking compressed air to it which your not suppose to do to any filter.

THo for your girls car, if she is not into all the required maintenance that a modded car needs, than i wouldn't put one in there.

 

I'm getting my mits on a RE-Amemiya intake kit soon, I rememeber reading an airfilter test including all the top brands, I'll dig it out and post it up tomorrow so you can all see. I think Blitz was the best, but in truth I don't remember.

 

http://www.bobistheoilguy.com/airfilter/airtest1.htm

 

As promised and it was Apexi that was best, not Blitz

http://www.mkiv.com/techarticles/filters_test/2/

 

if you read the fine print, apexi did the testing....

 

Im gonna guess that in Japan , they don't really deal with the dusty conditions/roads like we have over here.. So maximum filtration isnt that big of a deal to them..




But tuning is alot different in japan.

I mean no one runs blow through maf setup over here. They can do stuff that is not commonly seen over here.

But that is not to say they don't know what they are doing. Their stuff works.

Greedy also makes a foam filter


They are more like a venturi plate with some foam fence to keep stuff out.