I have asked this before, but I want to make sure its gonna be okay to do this.

I have a disgusting stock air filter that is in dire need of replacement. My car feels like its getting bottlenecked with its airflow. Anyhow, as my question has stated, I was wondering if switching to a drop in K&N would be okay air/fuel wise. My car is stock except for an aluminum AST, and the racing beat intake duct that takes in air from the front of the car. I would rather get a stock foam mazda filter if this K&N is going to pose any risk with the fuel management, and running lean. However if this isn't the case, any SAFE performance gain that I can get out of this in addition to possible (trying to convince myself) better gas mileage somehow would be great. What am I thinkin saying I'm going to get good gas mileage though. Again, I'd rather stay on the safe side, but I can't see how changing the filter to a better flowing one can really really make it run that lean. If I'm wrong, then thats why I'm posting this paranoia question.

 

Yep, OK. Get a downpipe next.

 

I agree with Ron, you can safely add intake and a downpipe without any fuel management... In fact, both of those mods actually help keep your car healthy, because the engine bay will be cooler. Most people think that 3 performance mods are safe before needing fuel management, but the best thing to do to monitor your mods would be to add a boost gauge if you don't have one already and make sure you're not boosting above 10 psi.

 

The K&N won't affect it that much. You would still be safe with that intake, dp, and cb at 10psi.

Defiantly do the K&N and a dp soon, you'll be plenty safe and actually be healthier.

 

When you do put in the k&n drop in, be sure the filter seats into the airbox correctly or else you may have some air seeping thru the sides of the filter.

The stock filter has a pastic grommet all around the perimeter of the filter and that ensures proper seating. K&n doesn't have it unfortunately, just the rubber seal around the edges.

 

thx for the input guys. K&N is on its way. How much does one of those things run? Aren't they a bit pricey? NE how, thx again. So even doing a DP is going to be okay as well. Nice.

 

I got to ask Ari Yallon the same thing when I called Rotary Performance. I, too, was a bit worried as I was planning on a downpipe and cat-back as well. He said to me that the stock airbox configuration is so much like a maze and so restrictive you will be lucky to see nominal gains, if any at all.

Kyle

 

Good point! I put a thin layer of high temp grease around the perimeter to kind of "stick" and seal the K&N in place before clamping it down. I also added a few very small sheet metal screws through the outside of the airbox frame to penetrate the OUTER rubber frame of the K&N to hold it in place. Not very elegant, but it works. If ANY air seeps past it you are wasting your time, and increasing engine wear. This is such a simple, but important, installation. Take your time and make sure it seals completely instead of just tossing it in casually. Too bad K&N missed this for the application, but almost all aftermarket parts just don't cut it when it comes down to fit and finish.

As far as the cost - the stock filter is damned expensive.
The K&N is a long term investment, and one, which I believe, works better than OEM.

 

K&N's are usually around $40. The stock Mazda filters I think are around $15.

 

OK, retarded ques, but how is a bit of a seal leak going to pose a problem with the airbox? Other than a bit of unfiltered air, how does this reduce engine life and performance? Of course I am taking note of what ur saying though, as a sealed airbox is better than an unsealed one. But the motor will just be getting a teeny bit of unfiltered air, and possibly a bit more flow right?

 

sipping air on the side like u said unfiltered air = dirty air= little sand particles and stuff like that, means u wear out the engine faster! Those egine are sensitive! Take a good care of it.....so we have more off them on the road then on the junkyard!

 

With a K&N drop in filter and the RB duct, you will see 1/2 to 1 pound of additional boost. This is probably OK if you don't do anything else. Before you put in a downpipe, you should install a boost gauge, and manual boost controller. If you don't, you might be boosting to 11 1/2 or 12 psi, and not even know it.

Boost controller link:
http://www.rx7turboturbo.com/robrobi...controller.htm

The boost controller is easy to install, and easy to remove if you don't like it.

Adam

 

I could not get my car to move at all past 10 psi with a intake, dp, cb. No boost controller or ported wastegate and with a clean cat and strong turbos. However when the temp dropped from 70 to 40 it went to 12 psi. I had a pettit ecu at the time.

 

I have a K&N for a stock airbox for sale. I'll let it go cheap. I'll even clean and re-oil it for you.

 

Each car is a little different. When I had my RB intake/K&N, and a down pipe, my boost pattern was a 11-14-11 with the stock ecu I did put down 235ish rwhp though. I'd get a boost gauge before the down pipe, just in case. CJ

 

is it ok if i drive my car if it is stock and i dont plant to mod it at all... is it ok to put 93 octane like the manual says too... jesh guys come on!

 

Should be ok. I have a RB and K&N with a downpipe and RB cat back and have been running it that way for 2 yrs. If anything it seems to run rich, especially when cold. You should get faster turbo spooling and a little more boost (perhaps with a spike). I would get a boost gauge asap. You might want to put on the boost gauge with the stock filter to see what your base line boost was. I would recommend the column mount gauge if you are trying to keep the stock look...

 

alright, went to kragen, I guess that filter is 54 bucks from them. Thats damn expensive for a drop in. Jeez. I was thinkin forty might have been a stretch. Well, I guess I can order it, or someone on this post was saying he could sell his to me? Is that thing in good shape? I know these things are reuseable, but I have one in my truck, and its really getting tough to get all the dirt out after a long time of having it in. If it is, I may be interested. Oh, and is it possible to get some sort of hardpipe intake system with two cone filters instead? I mean with the same stipulation that I would not have any sort of fuel management...IF so, which ones do u guys recommend? thx for the help.

 

Oh, and my car was having some probs. starting. Would this possibly be due to a really dirty air filter? I can't see how it could be, I was pecimistically thinking coolant is fouling plugs up, but someone tell me that changing my filter might help cure this. This rarely happens (the trouble starting), but I was thinking that if my car couldn't get air for starts, it would bog the motor out or something. If not, Im still replacing the filter, and was wondering as in my last post, whether or not it would be okay to run hardpipes and a separate cone filter for each turbo without needing fuel stuff yet, because I have no money for fuel management, and am in need of some cleaner and healthier airflow, so if I could just do the intakes because Im planning on doing that somewhere down the line anyhow, I figured why buy the K&N filter if I'm just going to replace it with new filters. But again, if this is a no no, please let me know. ^BUMP^

 

Yo Stevey - you're rambling dood.......

I would figure out your starting problems before doing anything else. That means new air filter (whatever) new fuel filter, new plugs, new plug wires, oil and filter. That's about $175.00 right there if you do the install yourself. If you still have the problem you need to figure it out before investing any money in mods.

You will not really see any significant gains until you have the entire intake, downpipe and catback on. It's garbage in, garbage out. Then you need boost control, yada yada...It sounds like you are on a pretty tight budget so put your dough into routine maintenance first.

If you have it running right, 13b's fire up damn quick all the time. Mine has never failed to start in a half a heartbeat.

 

If your filter was so dirty that it caused starting problems, your engine would barely run when once it was started.

Take Ron's advice. He's a God.

 

Paw140. Ron's a smart guy that knows RX7s. Don't spend your Sundays worshiping him!!

Stevey629. Stop wasting time. Buy the K&N filter and put it in your car. DO IT NOW!! Let us know how it works for you.

 

So I should probably take down my RonKMiller Shrine?

 

I wouldn't take down the shrine. I meant, don't spend ALL day on Sundays worshiping him.

 

Whoa...0.5 to 1 lb. boost increase? Is that what you saw? Is your wastegate working properly? Even with CB, DP, Efini Y-pipe, and modded stock airbox w/K&N, my car refused to go over 10 psi with the stock ECU (which was fine, obviously), and spikes were only up to 12. Only on cold nights was I able to get boost up to 11 psi.
Interestingly, with a Pettit ECU, my transition seems a bit better, even though the power overall is much greater. Although the spiking up to 14 psi will definitely upset the car while cornering hard in 3rd.