2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

anyone run theyre rex w/o an air filter?

Thread Tools
 
Search this Thread
 
Old 07-09-05, 11:08 PM
  #1  
I "lost" my emissions....

Thread Starter
 
DREYKO's Avatar
 
Join Date: Apr 2005
Location: lillington, nc
Posts: 1,764
Likes: 0
Received 3 Likes on 3 Posts
anyone run theyre rex w/o an air filter?

just with a empty box, how does that affect proformance and stuff?
Old 07-09-05, 11:10 PM
  #2  
RX7less **(

iTrader: (6)
 
igottafc's Avatar
 
Join Date: Dec 2003
Location: Novi Michigan
Posts: 6,916
Likes: 0
Received 0 Likes on 0 Posts
is it worth it to sacrifice your engine for 2-3 horsepower? just get a high flow filter or ditchs the stock airbox and get an actual intake system with a filter.
Old 07-09-05, 11:21 PM
  #3  
I "lost" my emissions....

Thread Starter
 
DREYKO's Avatar
 
Join Date: Apr 2005
Location: lillington, nc
Posts: 1,764
Likes: 0
Received 3 Likes on 3 Posts
no but you just cant get a filter around here and i was just wondering...
Old 07-09-05, 11:24 PM
  #4  
RX7less **(

iTrader: (6)
 
igottafc's Avatar
 
Join Date: Dec 2003
Location: Novi Michigan
Posts: 6,916
Likes: 0
Received 0 Likes on 0 Posts
you could do it but its not a smart idea. Unless you lived in a relativly clean air area i wouldnt. id be worried about sucking up road dirt into the engine. although it may not destroy the engine right away, over time too much of it could wear the internals of your motor which could cause your engine to **** out
Old 07-09-05, 11:32 PM
  #5  
I "lost" my emissions....

Thread Starter
 
DREYKO's Avatar
 
Join Date: Apr 2005
Location: lillington, nc
Posts: 1,764
Likes: 0
Received 3 Likes on 3 Posts
aight, thx for the advice, ill put mine back in (dirty though it is) and see about ordering one
Old 07-09-05, 11:57 PM
  #6  
Senior Member

 
rx7ofdoom's Avatar
 
Join Date: Mar 2004
Location: So Cal
Posts: 302
Likes: 0
Received 0 Likes on 0 Posts
hey, yeah dont run no filter not worth the risks.
Old 07-09-05, 11:59 PM
  #7  
omae mo na!

 
sleejay's Avatar
 
Join Date: Nov 2004
Location: NEW JERSEY
Posts: 861
Likes: 0
Received 0 Likes on 0 Posts
corner seals are weak enough with clean air, dont go throwing particulates in there and expecting a happy engine
Old 07-09-05, 11:59 PM
  #8  
GET OFF MY LAWN

iTrader: (1)
 
jgrewe's Avatar
 
Join Date: Feb 2005
Location: Fla.
Posts: 2,837
Likes: 0
Received 2 Likes on 2 Posts
Only two kinds of vehicles don't need an air filter; an airplane that never lands, and a boat that never docks. Order a K&N to fit your stock box its cheap insurance.
Old 07-10-05, 12:01 AM
  #9  
Rotary Noob

 
MapOfTaziFoSho's Avatar
 
Join Date: Jun 2005
Location: MI
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by DREYKO
just with a empty box, how does that affect proformance and stuff?


Originally Posted by DREYKO
aight, thx for the advice, ill put mine back in (dirty though it is) and see about ordering one

I cannot beleive no one called this guy an idiot...
Old 07-10-05, 12:04 AM
  #10  
Senior Member

 
rx7ofdoom's Avatar
 
Join Date: Mar 2004
Location: So Cal
Posts: 302
Likes: 0
Received 0 Likes on 0 Posts
everyone has to start somewhere no reason to rub salt in his wounds. he's already possibly damaged his engine thats enough .
Old 07-10-05, 12:15 AM
  #11  
I'm a boost creep...

 
NZConvertible's Avatar
 
Join Date: Jan 2002
Location: Auckland, New Zealand
Posts: 15,608
Likes: 0
Received 8 Likes on 8 Posts
Originally Posted by igottafc
is it worth it to sacrifice your engine for 2-3 horsepower? just get a high flow filter...
If removing the filter will only get you 2-3hp (and that'd only be if the filter is dirty), why would you waste your money on a so-called "performance" filter? Don't believe the marketing BS, drop-in filters don't do jack for performance.
Old 07-10-05, 12:38 AM
  #12  
Make Money.
iTrader: (6)
 
eriksseven's Avatar
 
Join Date: Oct 2003
Location: Seattle
Posts: 4,137
Received 8 Likes on 2 Posts
^ what does? (seriously)

BTW, I have a K&N drop-in and I think it works better than the basic stock filter... Probably smarter than getting rid of the stock box and placing an open filter in my engine bay...

I'm assuming a true CAI is the only thing you'd stand behind NZ?
Old 07-10-05, 12:47 AM
  #13  
Rotary Freak

 
Syonyk's Avatar
 
Join Date: Jun 2004
Location: Ames, IA
Posts: 2,718
Likes: 0
Received 1 Like on 1 Post
Originally Posted by jgrewe
Only two kinds of vehicles don't need an air filter; an airplane that never lands, and a boat that never docks. Order a K&N to fit your stock box its cheap insurance.
Actually, some airplanes have two intake sources - one filtered source for low altitude takeoff/landing, and then an unfiltered (usually ram air) source for use at altitude.

-=Russ=-
Old 07-10-05, 01:09 AM
  #14  
Senior Member

 
rx7ofdoom's Avatar
 
Join Date: Mar 2004
Location: So Cal
Posts: 302
Likes: 0
Received 0 Likes on 0 Posts
learn something everyday
Old 07-10-05, 01:22 AM
  #15  
I'm a boost creep...

 
NZConvertible's Avatar
 
Join Date: Jan 2002
Location: Auckland, New Zealand
Posts: 15,608
Likes: 0
Received 8 Likes on 8 Posts
Originally Posted by eriksseven
I have a K&N drop-in and I think it works better than the basic stock filter...
Why? Did you do back-to-back pressure drop and performance comparisons between a new OEM filter and the K&N? Or do do you just hope it made a difference because you paid money for it? Don't be offended, that's exactly what most people think when they buy aftermarket stuff...

And remember than the filter's #1 job is to filter, and there's not an aftermarket filter available that "works better than the stock filter" in that regard. Aftermarket filters do a very average job at filtering compared to OEM.

Probably smarter than getting rid of the stock box and placing an open filter in my engine bay...
Maybe, but putting a new OEM filter in would've had the same effect and been cheaper. I know the K&N is reusable, but once you take the filter purchase cost, cleaning kit cost and cleaning interval, and compare that to Mazda's recommended filter replacement interval, you'll see the K&N takes a long time to pay for itself. Too long IMO to consider the long-term cost savings as a genuine advantage.

I'm assuming a true CAI is the only thing you'd stand behind NZ?
A "true" CAI is simply any method that ensures only outside air enters the engine. It doesn't necessarily mean using a pod filter as part of the intake system, but if you want decent performance in an FC that's pretty much what you need. Personally I like the idea of using stock airboxes (with stock filters) modified for better flow (bigger and better inlets and outlets) but the FC's airbox is just not suitable for that approach. It was designed to fit in a very constrained space. A high-flow intake design with a heat-shield and a path for cold air is best for the FC.
Old 07-10-05, 07:14 AM
  #16  
RX7less **(

iTrader: (6)
 
igottafc's Avatar
 
Join Date: Dec 2003
Location: Novi Michigan
Posts: 6,916
Likes: 0
Received 0 Likes on 0 Posts
i think its the peace in mind that you have a "high flow filter" that some people need
Old 07-10-05, 07:49 AM
  #17  
Banned. I got OWNED!!!
 
homebrewer's Avatar
 
Join Date: Feb 2005
Location: Colorado
Posts: 265
Likes: 0
Received 0 Likes on 0 Posts
I hate to burst your bubbles but K&N filters do not filter as well as OEM. This information is based on numerous used oil analysis that show elevated levels of silcon in the oil with K&N filters. What this means is increased wear. Do a search on www.bobistheoilguy.com in their oil analysis results forum section and you'll see the facts for yourself.
Old 07-10-05, 11:14 AM
  #18  
HAILERS

 
HAILERS's Avatar
 
Join Date: May 2001
Location: FORT WORTH, TEXAS,USA
Posts: 20,563
Likes: 0
Received 21 Likes on 19 Posts
The airplanes I work on don't have an air filter at all. 2 cent humor, but true.
Old 07-10-05, 01:40 PM
  #19  
Rotary Freak

 
Syonyk's Avatar
 
Join Date: Jun 2004
Location: Ames, IA
Posts: 2,718
Likes: 0
Received 1 Like on 1 Post
Originally Posted by HAILERS
The airplanes I work on don't have an air filter at all. 2 cent humor, but true.
And do you occasionally have to inspect the engines after they ingest birds?

-=Russ=-
Old 07-10-05, 01:49 PM
  #20  
Sharp Claws

iTrader: (30)
 
RotaryEvolution's Avatar
 
Join Date: Oct 2003
Location: Central Florida
Posts: 5,107
Likes: 0
Received 41 Likes on 40 Posts
aftermarket filters do flow slightly better than OEM since they are not packed as tightly as OEM, that said they also do not filter as well.

is it worth it paying $70 or whatever they cost for a couple of HP gain and an increase in wear?

those who say they do nothing are wrong but it's hardly worth even popping the box open to change the filter for an upgraded one..
Old 07-10-05, 02:11 PM
  #21  
Rotary Enthusiast

 
88 SE's Avatar
 
Join Date: Mar 2002
Location: Phoenix
Posts: 818
Likes: 0
Received 1 Like on 1 Post
You have to ask yourself which you would rather have filtering your engine:

A filter that is made well enough to filter out dust with its own media or a filter that relies on oil to filter the air.

I'll always chooe the first myself.

That said, there are dry mesh filters out there you can buy...

If you must go with the cone type aftermarket, K&N and HKS megaflow are cited as the worst filters out there as far as their filtering capability.

APEX'i and Team Green are known for making filters capable of doing a good job.
Old 07-10-05, 02:25 PM
  #22  
Senior Member

 
theloudroom's Avatar
 
Join Date: Sep 2003
Location: Syracuse, New York
Posts: 488
Likes: 0
Received 0 Likes on 0 Posts
Here's the best source I run across.

http://www.mkiv.com/techarticles/fil...t/2/index.html

In this test K&N was ranked second to Apexi, neither were rated poor.

Last edited by theloudroom; 07-10-05 at 02:35 PM.
Old 07-10-05, 04:04 PM
  #23  
I'm a boost creep...

 
NZConvertible's Avatar
 
Join Date: Jan 2002
Location: Auckland, New Zealand
Posts: 15,608
Likes: 0
Received 8 Likes on 8 Posts
Originally Posted by Karack
those who say they do nothing are wrong...
Note that I didn't say they did "nothing". But numerous tests I've seen show than OEM filters cause only a tiny amount of restriction compared to the rest of the intake system (let alone the engine itself and the exhaust). Even if an aftermarket filter is half as restrictive as stock, half of a tiny restriction is still a tiny restriction, so the benefits are going to be equally tiny.

You could say that removing the cirarette lighter improves performce, and you'd be technically right, but we don't...
Old 07-10-05, 05:04 PM
  #24  
Rotary Enthusiast

 
88 SE's Avatar
 
Join Date: Mar 2002
Location: Phoenix
Posts: 818
Likes: 0
Received 1 Like on 1 Post
Originally Posted by theloudroom
Here's the best source I run across.

http://www.mkiv.com/techarticles/fil...t/2/index.html

In this test K&N was ranked second to Apexi, neither were rated poor.
3 cheers for dry mesh filters!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Queppa
New Member RX-7 Technical
8
09-02-18 09:53 AM
alphawolff
1st Generation Specific (1979-1985)
17
11-17-15 05:57 PM
LunchboxSA22
2nd Generation Specific (1986-1992)
37
10-26-15 10:53 AM
rkhanso
2nd Generation Specific (1986-1992)
1
08-13-15 11:40 AM



Quick Reply: anyone run theyre rex w/o an air filter?



All times are GMT -5. The time now is 07:56 PM.