EEEKKKKK crappest filter made... element must be replaced every 10K miles...

If they even get the least bit dirty, the intake on a Rotary engine (and most V8 engines) will pull them apart.

Plus they only stop about 10% of the dirt.

SAY NO TO GREEN MUSHROOMS!

Everyone read this:

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

 

amazing results....but my own TESTING(actual driving) over the last 7 years tells me otherwise....I toss out the filter by 10k-15k and get a new one....I have driven over 70k miles in cars with HKS AFS and never had any issues...just before replying I went to my car and popped off the filter and ran my hand through the front portion of the AFM and come up with a VERY little oil and 0 dust/dirt... and as far as the comment ..."If they get the LEAST BIT dirty the intake of the RX7 ...will pull them apart..." is simply not true...it would take at least 30k+ in a dirty location to cause the filter to DRY and then break....MOST of those people claiming it falls apart are those that do not replace the filter EVER and then call the filter a piece of ****..MARK-how many filters have you had sucked in your intake that you replaced on time? Or how many have you heard of being sucked in that you KNOW were replaced on time?..maybe 1 or two? ....out of maybe millions sold..


or better yet..maybe those people having problems are WASHING the filter

 

Yes, most of the people who have problems with the HKS foam filter are washing it or not replacing it. While I don't like it as much as the K&N filters, I have not had a problem with the HKS filter falling apart, and I used it in very hot conditions in environments with lots of sand, clay dust, sulfur dust, and pollen.

The article posted by Icemark was produced by Apexi vendors, and their ghetto testing was not in accordance with SAE standards.

 

plus the HP increase of the HKS is hard to beat..a lot of bang for the buck(initial price anyway-over time, replacing the filter will add up)

 

The only downside to the foam HKS I see is that you have to change them so often. Other than that, I've never had an issue on my GVR4. I like them because they aren't as bulky as most cone filters but when they are dirty performance and mileage will suffer. We had an old shop beater (280ZX turbo) a few years back and the HKS filter in that car got so dirty and gummed up (years of driving) that the car wouldn't start. I replaced the filter and bam, started right up.

K&N is my preference (use one on the FC) but the GVR4 has an HKS since there isn't much room for a decent size K&N with the TID I have.

 

actually it was orginallly on a tech article in Japan...then later on the Mk IV supra club... with no alignment to Apexi

But these pictures say it all to me:
Green mushroom 13+ hp and what it let through:


K&N 13+ HP and what it let through:


This backs up exactly what I have seen in the real world, both on my cars and others.

Green Mushrooms = fine dust in the intake tubes after the filter.

K&N = no dirt