Single Turbo RX-7's Questions about all aspects of single turbo setups.

How many of you use no Air filter on your turbo?

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Old Feb 2, 2006 | 10:46 AM
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How many of you use no Air filter on your turbo?

As of right now i have a metal mesh that covers the inlet and the holes are really small on it so there isn't anything that can really get through there. I like it this way, but don't really know if there might be any benefits of getting an air filter.

Plus i don't really have enough room for the damn thing.

Anybody else runs without one... if so for how long?
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Old Feb 2, 2006 | 11:22 AM
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bad idea...there is so much little dust/road grime/sand/basically anything and everything your turbo will suck up...its basically going to sandblast your housings

I've read, that a large K&N (definitely better for street driving) will flow better than mesh screens...more sureface area for air to travel through.

I've always gone by the rule of thumb, "Use the biggest air filter you can fit"
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Old Feb 2, 2006 | 11:38 AM
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When my car was on the dyno I pulled the air filter off to see what the difference was... the car made 3.5 more rwhp. It's not worth trashing your turbo for only a couple of hp .

Turbo wheels are pretty fragile and it only takes one little thing to get sucked up before your turbo and engine are toast.
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Old Feb 2, 2006 | 11:39 AM
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Really REALLY bad idea. I've taken apart MANY turbo's that ran without a filter on them. They all looked like they got sand blasted using gravel and glass. In some cases, the impeller blades wore so thin they were very close to breaking off. Now imagine all this sand blasting INSIDE YOUR ENGINE. The couple hp gain is NOT worth it. Furthermore, metal screens tend to HURT flow moreso them a proper sized filter. Like dubulup said, you can never get too big of a filter. If you have to, run a pipe on the turbo inlet and place the filter else were in the engine bay were it fits.

~Mike...................
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Old Feb 2, 2006 | 11:48 AM
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I just got a K&N for the AF61. It was the largest that I could find. 4" at the section that connects to the turbo and 7" long. Bigger is better
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Old Feb 2, 2006 | 11:59 AM
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You can run the mesh temporarily.

I took my airfilter off on the dyno one time and it sucked my boost controller in. Needless to say, my turbo was trashed.
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Old Feb 2, 2006 | 12:28 PM
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LOL, I read a few years ago on this forum about a guy that used a tee shirt ....yup it sucked it right up.
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Old Feb 2, 2006 | 01:15 PM
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I actually used a metal screen for a few months. After two months, the screen had slowly been sucked apart.
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Old Feb 2, 2006 | 01:51 PM
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Now, you use that auto zone one? How's that working for you? The thing looks restrictive to me.
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Old Feb 2, 2006 | 01:54 PM
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I know alot of dudes that use stocking on n/a cars. I wouldnt suggest no filter on a turbo car though. My friend ran his rx2 like thta for a while and now he tells me his fins are torn up and needs a new t66. Pricey??
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Old Feb 2, 2006 | 02:00 PM
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Originally Posted by BoOsTin FD
Now, you use that auto zone one? How's that working for you? The thing looks restrictive to me.
Have you seen mine? I have no problems with it.
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Old Feb 2, 2006 | 02:41 PM
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Crap, I was thinking of running a mesh filter on my car, too, there's just NO room for an air filter. I MIGHT be able to get an HKS mushroom deelie on there, but that's it, and I hear those are bad for turbo applications anyways...
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Old Feb 2, 2006 | 03:49 PM
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Originally Posted by LUPE
Have you seen mine? I have no problems with it.
Yeah I've seen yours when you guys finished putting the side exhaust

I'll probably get one of those for now...
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Old Feb 2, 2006 | 03:56 PM
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Originally Posted by BoOsTin FD
Yeah I've seen yours when you guys finished putting the side exhaust

I'll probably get one of those for now...
I'll probaby take mine off while Kan tunes/dyno's my car saturday.
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Old Feb 2, 2006 | 04:00 PM
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Come Awn Saturday!!!
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Old Feb 2, 2006 | 04:01 PM
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One word - K&N

Washed and lightly oiled yearly (every 10K miles or so) ......I'll see if I can cross-link a post of my engine bay with it.

Beast

Ah, here it is....this was with a 13BREW vs. the 13BRE in it now.....same basic fit.

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Old Feb 2, 2006 | 06:38 PM
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Originally Posted by Beast From The East
YEAH! K&N!!!
IT WON'T FIT, WAAAAAAHHH. Seriously, I have about 4-5" at most between the turbo inlet and the radiator. Anyone know a good, flat, mushroom filter that won't get sucked into my turbo?
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Old Feb 2, 2006 | 06:58 PM
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I just bought the auto zone one... 25 bucks and it fits fine..
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Old Feb 3, 2006 | 05:29 AM
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Mesh screens usually flow worse than a filter. A tight mesh will flow poorly (and is at risk for being sucked into the turbo). Metal meshes have a deceiving amount of blocked versus open area. 30-40% blockage is not uncommon, even though their appearance is deceptive. Examples: http://s2.pegasusautoracing.com/048.pdf

Don't use anything flexible like a stocking -- it will get sucked into the turbo very easily. I would be very surprised if it flowed well, too.

K&N makes a very short filter with a 4" ID base. The element is pretty small and it seems like it would be restrictive, but I made 410HP with this filter in place. And it didn't look like it was sucking in on itself in any noticable way. Another guy at the same dyno tune day had an HKS mushroom that would suck itself in a few inches during the runs. We swapped my little K&N on there and it made better power and didn't noticably deform during the runs. I suppose it will require more cleaning (and make somewhat less power) than a larger filter, but it works and doesn't seem to be a major restriction.

Can you move anything else around to make more room for a filter? It might be worth it if you can tilt/move your radiator more forward to make room.

-Max

Last edited by maxcooper; Feb 3, 2006 at 05:31 AM. Reason: D'oh, I just realized you already got a filter
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Old Feb 3, 2006 | 08:32 AM
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Might be a little overkill
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Old Feb 3, 2006 | 01:39 PM
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thats one hell of an air filter! i have have been running a mesh screen. ii have very little room between the front cover and intercooler piping. probably 3 inch of space. would a 90 degree bend off the turbo be very restrictive?
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Old Feb 3, 2006 | 02:16 PM
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^better than sandblasting your rotor housings
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Old Feb 3, 2006 | 04:39 PM
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good point, i found some smaller filters on K&N's website that may work , but they r very small. I may just have to do a little cutting and welding and make a new charge pipe to give my self more room. Im glad to see this thread come up, as i was always a little worried about my screen .
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Old Feb 3, 2006 | 07:44 PM
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I have seen very serious turbo and engine failure using screens and the HKS foam filter stuff.....I may offend some folks, but that stuff is pure crap.


I have three short K&Ns on my Triumph as well, looks like this, however, I made mine taller by cutting and rewelding the towers to support a 4 inch tall filter vs. these twin inch tall filters. Butts right up against the fender well - I ended up drilling a hole in the fender arch so I can get a Philips screwdriver through to unscrew the cover for the middle one:


Just get creative....

Beast
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Old Feb 3, 2006 | 10:42 PM
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Originally Posted by Nuvolari
LOL, I read a few years ago on this forum about a guy that used a tee shirt ....yup it sucked it right up.
The legacy of brian thompson lives on......
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