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-   -   Installed K&n Cone Filter And Adapter, Now Runs Like Crap (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/installed-k-n-cone-filter-adapter-now-runs-like-crap-696086/)

flatblacksleeper 10-12-07 10:24 PM
Installed K&n Cone Filter And Adapter, Now Runs Like Crap
 
88 gxl, car ran fine before, all was installed corrrect, installed a conicical filter, and maf adapter, now there is a high rpm miss i think, power seemed great till like 6000 rpm, then went flat.

any input would be great

is there less cold air now that vent duct over radiator is not hooked up?

Fero313 10-12-07 10:30 PM
more air flow, probably hotter air...

is the AFM level? the flapper should move parallel with the ground so that gravity won't pull the door open or closed (even if just a little) so they say on the forums

flatblacksleeper 10-12-07 11:30 PM
pretty sure its level

KillaKitiie 10-12-07 11:34 PM
Originally Posted by flatblacksleeper (Post 7415298)
88 gxl, car ran fine before, all was installed corrrect, installed a conicical filter, and maf adapter, now there is a high rpm miss i think, power seemed great till like 6000 rpm, then went flat.

any input would be great

is there less cold air now that vent duct over radiator is not hooked up?
Of course the car wont make power after 6k rpm's..I would double check all your connect's and make sure you have everything connected right.

texFCturboII 10-12-07 11:35 PM
just because the air was warmer it wouldn't cause the car to run shitty.

flatblacksleeper 10-13-07 12:16 AM
Originally Posted by rotorman85 (Post 7415438)
Of course the car wont make power after 6k rpm's..I would double check all your connect's and make sure you have everything connected right.
it normally makes power past the buzzer,lol
it started breakin up at full throttle, third gear, like 5500 rpm and up

forced inducted fd dude 10-13-07 12:24 AM
check for leaks?

flatblacksleeper 10-13-07 12:52 AM
i visually did, i will with propellant tomorrof

flamin-roids 10-13-07 01:31 AM
Someone told me a while back that your car will run lean after installing intake and exhaust. You should try some TII injectors for secondaries or maybe a new fuel pump. I had the same issue but in your case it could be anything, like a bad O2 sensor perhaps.

Roen 10-13-07 02:14 AM
exhaust maybe.....open filter will probably cause your car to run richer due to less air going into the engine.......more airflow of hotter air = less air mass overall

detonation 10-13-07 02:15 AM
get it dynoed asap...intake and exhaust mods can make the car leaner or richer...and it would probably help if the filter was not exposed to hot air...hotter intake air = less power

flatblacksleeper 10-13-07 02:29 AM
should i put the airbox back in, and do a drop in filter?

1st7 10-13-07 03:13 AM
Good Idea!!!!

walken 10-13-07 04:10 AM
get a new fuel filter

Snailz 10-13-07 05:27 AM
Just on that, has anyone done a write up for putting the K&N into the stock airbox? I had a look at it and it didnt look all that possible. Any help would be great!

InGroundEffect 10-13-07 08:52 AM
Originally Posted by flamin-roids (Post 7415640)
Someone told me a while back that your car will run lean after installing intake and exhaust. You should try some TII injectors for secondaries or maybe a new fuel pump. I had the same issue but in your case it could be anything, like a bad O2 sensor perhaps.
Uh, no. I am running Stock Injectors and Fuel pump each with over 300k miles with Street Headers, Street Port and 2.5" Exhasut 6 ports wired open, no airbox with open filter like K&N. My air fuel on a Dyno are dead on and dyno ~160hp to the wheels.

flatblacksleeper 10-13-07 09:35 AM
i have not replaced fuel filter yet, might help, car was on a 1/8th tank, would that kill me?

but car always ran rich, and ran strong before a stupid cone filter




............i was talking about the k&n thats a factory square filter, thats called a drop in, instead of the cone filter...........

Aaron Cake 10-13-07 10:05 AM
Originally Posted by flamin-roids (Post 7415640)
Someone told me a while back that your car will run lean after installing intake and exhaust. You should try some TII injectors for secondaries or maybe a new fuel pump. I had the same issue but in your case it could be anything, like a bad O2 sensor perhaps.
Originally Posted by detonation (Post 7415695)
get it dynoed asap...intake and exhaust mods can make the car leaner or richer...and it would probably help if the filter was not exposed to hot air...hotter intake air = less power
There's no reason to upgrade the fuel system, and there's no reason to spend $100 an hour to book a dyno on a car where there is no way to tune the fuel curve.

A simple troubleshooting step would be to remove the K&N filter and see if the car improves. If so, then the issue is with the filter.

What was done with the air pump line that would normally be connected to the airbox?

KillaKitiie 10-13-07 01:00 PM
Seriously i ran the K&N filter on my 87 GXL for about 2 years with no problem's and telling this guy to dyno his car and to upgrade his injector's is just ridiculous!

311unity13B 10-13-07 02:13 PM
check your grounds, lol

Evil Aviator 10-13-07 02:41 PM
Originally Posted by flatblacksleeper (Post 7415298)
is there less cold air now that vent duct over radiator is not hooked up?
Yes, the intake air will be a little warmer now, but that shouldn't cause the problem that you describe. Something else is wrong, most likely something that you accidentally disconnected when removing the stock air box, although it could be something not related to your recent work.

Originally Posted by flamin-roids (Post 7415640)
Someone told me a while back that your car will run lean after installing intake and exhaust.
Slap that person. Our cars have an airflow meter, so no matter how you change the airflow to the engine, it still measures it. The same applies if the air is heated or cooled.

Originally Posted by flamin-roids (Post 7415640)
You should try some TII injectors for secondaries or maybe a new fuel pump.
TII injectors will make the engine run like crap unless it has a properly tuned aftermarket fuel computer to control them.

Originally Posted by Snailz (Post 7415867)
Just on that, has anyone done a write up for putting the K&N into the stock airbox? I had a look at it and it didnt look all that possible. Any help would be great!
1. Buy K&N air filter 33-2017.
2. Unscrew the screws on the stock air box.
3. Remove the cover of the stock air box.
4. Remove the old air filter.
5. Install the K&N air filter.
6. Replace the cover of the stock air box.
7. Install the air box screws.
8. Nominate Evil Aviator for a Nobel Peace Prize for writing this complicated and innovative process.

flatblacksleeper 10-13-07 02:45 PM
i left the hose off to the air pump, since i have no cats and air pump is disconnected for now.

i made 2 brackets, leveled the maf out, full tank of gas, and made a air scoop to the filter based off the oem scoop over the radiator.

we will see what happens


Originally Posted by Aaron Cake (Post 7416113)
There's no reason to upgrade the fuel system, and there's no reason to spend $100 an hour to book a dyno on a car where there is no way to tune the fuel curve.

A simple troubleshooting step would be to remove the K&N filter and see if the car improves. If so, then the issue is with the filter.

What was done with the air pump line that would normally be connected to the airbox?

incubuseva 10-13-07 03:34 PM
Evil, I think he meant using a cone filter in the stock box. It's been a while since I've looked at the stock box, so I dunno if that would work or not.

But you get my nomination!



Double check all of your hoses + wires for lose connections.

flatblacksleeper 10-13-07 03:35 PM
just got back, ran strong, no miss/flatness, very responsive

makes a sloppy air sucking noise at low rpm though.....i can only hear it with windows open
this is my first mass air car, so that may be it, may be the air flyin past the vane

incubuseva 10-13-07 04:53 PM
Mine doesn't sound sloppy. When I'm on the throttle a bit, I can hear the 'bark' of the intake.

clokker 10-13-07 05:32 PM
Originally Posted by flatblacksleeper (Post 7416618)
i made 2 brackets, leveled the maf out, full tank of gas, and made a air scoop to the filter based off the oem scoop over the radiator.

we will see what happens
Originally Posted by flatblacksleeper
just got back, ran strong, no miss/flatness, very responsive
OK...so the problem wasn't with the filter at all.
I'm guessing that the two new brackets just positioned the AFM properly.
Now you can ditch that OEM air feed since it's doing nothing whatsoever.

Evil Aviator 10-13-07 08:44 PM
Originally Posted by incubuseva (Post 7416729)
Evil, I think he meant using a cone filter in the stock box. It's been a while since I've looked at the stock box, so I dunno if that would work or not.
I know, I was just having fun, and I think he may have not known that a drop-in K&N filter is available. As for trying to wedge a cone filter in the stock air box, there would be no point in that, even if it fit.

Originally Posted by incubuseva (Post 7416729)
EvilBut you get my nomination!
Woohoo! Now I'm even with Rush Limbaugh, and on the heels of Al Gore!

misterstyx69 10-13-07 10:46 PM
How are you getting any pressure to activate your Auxilary ports?...suggestion..wire them open,(just as a TEST)..go for another spin..does it Operate Better Now in the Higher RPM's?.

flatblacksleeper 10-13-07 10:51 PM
i have the vacuum line hooked up, i have the bonez race pipe, had a line tapped into it, so my ports should be working

flatblacksleeper 10-14-07 12:56 PM
low rpm air suck sounds choppy, the higher smooooooth air suck,lol

incubuseva 10-14-07 01:59 PM
That sounds about right.


So the only 'problem' that you're having is with the sound of it?

flatblacksleeper 10-14-07 09:27 PM
yeah, runs great

i think its the mass air making the noise.....the vane door

Evil Aviator 10-14-07 09:42 PM
Originally Posted by flatblacksleeper (Post 7420094)
yeah, runs great

i think its the mass air making the noise.....the vane door
The stock air boxes on most cars are designed to reduce intake noise. It will make that noise even if you remove the AFM and install a standalone EMS. If it really bothers you then make a "cold air" box around the filter. The box will not silence the noise as much as the stock box, but it will help some.

Roen 10-17-07 09:49 AM
Originally Posted by Evil Aviator (Post 7420148)
The stock air boxes on most cars are designed to reduce intake noise. It will make that noise even if you remove the AFM and install a standalone EMS. If it really bothers you then make a "cold air" box around the filter. The box will not silence the noise as much as the stock box, but it will help some.
and give you more power!

only caveat is, you have to cut into the body to get cold air to the filter. If you install one of thouse headlight ducts, the aerodynamic profile of the FC will start pulling air out of the duct until you go above a certain speed! (methinks it is either 60 or 120).

Evil Aviator 10-17-07 04:16 PM
Originally Posted by Roen (Post 7429024)
and give you more power!
It only gives more power if it is designed correctly.

Originally Posted by Roen (Post 7429024)
only caveat is, you have to cut into the body to get cold air to the filter.
That is not necessarily true. It all depends on how you go about the process.

[QUOTE=Roen;7429024]If you install one of thouse headlight ducts, the aerodynamic profile of the FC will start pulling air out of the duct until you go above a certain speed! (methinks it is either 60 or 120).[QUOTE]
That is one of those wonderful internet myths. The small amount of dynamic pressure produced will never counter the ram air going into the duct.

The two main problems with typical headlight ducts are that they are too small, and/or do not work well when the headlight is raised.

Roen 10-17-07 04:26 PM
[QUOTE=Evil Aviator;7430231]It only gives more power if it is designed correctly.


That is not necessarily true. It all depends on how you go about the process.

[QUOTE=Roen;7429024]If you install one of thouse headlight ducts, the aerodynamic profile of the FC will start pulling air out of the duct until you go above a certain speed! (methinks it is either 60 or 120).
That is one of those wonderful internet myths. The small amount of dynamic pressure produced will never counter the ram air going into the duct.

The two main problems with typical headlight ducts are that they are too small, and/or do not work well when the headlight is raised.
I would think that as long as you have a cone, which flows better than stock, and a means of ensuring that the air it receives is close to ambient temp, it will produce more power than stock.

How would you suggest getting air to the filter? Build a box with a cutout and use the stock feeder tube to flow air into the box?

I thought the aerodynamic profile of the FC details which way the air flows as it interacts with the body at speed?

Evil Aviator 10-17-07 10:25 PM
Originally Posted by Roen (Post 7430263)
I would think that as long as you have a cone, which flows better than stock, and a means of ensuring that the air it receives is close to ambient temp, it will produce more power than stock.
That would be true assuming that the custom air box, plumbing, and filter have a total flow that is better than stock. The problem is that a lot of custom air intakes are not designed properly, and have more restriction than stock, which negates the higher flowing filter, and sometimes even results in lower engine performance. If you think about it, since the stock car already has an ambient air intake, temperature will be a constant, so the goal of a custom intake would be to optimize the pressure (or in non-engineering internet forum terms you would want to reduce the restriction).

Originally Posted by Roen (Post 7430263)
How would you suggest getting air to the filter? Build a box with a cutout and use the stock feeder tube to flow air into the box?
For a stock non-turbo engine, I recommend just sticking with the stock air box. For a turbocharged engine, you can simply build a deflector type shroud to keep the radiator discharge air away from your cone intake. The stock feeder tube is a bit small and convoluted for a high-performance application. A good functional high-performance intake looks something like this:
http://www.mazdatrix.com/faqpics/roadrace/ep01123ib.jpg

Originally Posted by Roen (Post 7430263)
I thought the aerodynamic profile of the FC details which way the air flows as it interacts with the body at speed?
When I uploaded that picture several years ago, I intended it to help out forum members, but it appears to have confused them more, lol. It simply shows the pressure vectors around the car while it is at speed. While you would want to try and place your various ducts in the high pressure areas for best results, even the lowest pressure areas are not capable of sucking the air backwards and starving a ram air inlet.

ForgottenMindset 10-17-07 11:25 PM
The k&n handbook doesn't specify a hp increase for fc's. For the money, its a waste anyways


I worked at advance auto up till about 2 hours ago

Roen 10-18-07 09:44 AM
Originally Posted by Evil Aviator (Post 7431470)
That would be true assuming that the custom air box, plumbing, and filter have a total flow that is better than stock. The problem is that a lot of custom air intakes are not designed properly, and have more restriction than stock, which negates the higher flowing filter, and sometimes even results in lower engine performance. If you think about it, since the stock car already has an ambient air intake, temperature will be a constant, so the goal of a custom intake would be to optimize the pressure (or in non-engineering internet forum terms you would want to reduce the restriction).


For a stock non-turbo engine, I recommend just sticking with the stock air box. For a turbocharged engine, you can simply build a deflector type shroud to keep the radiator discharge air away from your cone intake. The stock feeder tube is a bit small and convoluted for a high-performance application. A good functional high-performance intake looks something like this:
http://www.mazdatrix.com/faqpics/roadrace/ep01123ib.jpg


When I uploaded that picture several years ago, I intended it to help out forum members, but it appears to have confused them more, lol. It simply shows the pressure vectors around the car while it is at speed. While you would want to try and place your various ducts in the high pressure areas for best results, even the lowest pressure areas are not capable of sucking the air backwards and starving a ram air inlet.
Um.....that's a picture of a filtered ITB setup.....something that's beyond the scope of this discussion.

The only restriction I can think of is air starvation, if you use a box, such as the Mariah Box, and cut a slot for the stock air tube to feed air into. Put a high flowing cone filter like a K&N or APEX'i and you should have a decent cold air cone intake.

Evil Aviator 10-18-07 05:23 PM
Originally Posted by Roen (Post 7432567)
Um.....that's a picture of a filtered ITB setup.....something that's beyond the scope of this discussion.
Just because it is beyond the scope of your comprehension doesn't mean that it is beyond the scope of this discussion. ;)

Roen 10-18-07 05:44 PM
[rant]

I thought we were sticking intake upgrades using the stock throttle body. If intake was completely free, I would've brought up ITB's a long time ago. Still, from what I've been told, the best part of our induction system is the throttle body, and an ITB on a stock engine would probably be good for only 5 hp.

I'm still unsure how much a filter impacts the ITB setup. A lot of S2000 guys say that their filter robs upwards of 40 hp from their ITB setup . While that number is a bit high to be believable, alternatives do exist such as mesh screens or running open ITB's. While that last option isn't recommended for the street, a lot of S2000 guys run it without problems. I'm not as brave, and can't wait until I hear one of them complain about sucking in a large rock that made its way into the engine bay, or something similar. Still, no filter restriction does mean max power.

[/rant]

Evil Aviator 10-18-07 06:32 PM
Originally Posted by Roen (Post 7434086)
I thought we were sticking intake upgrades using the stock throttle body. If intake was completely free, I would've brought up ITB's a long time ago.
Look at the diameter of the intake pipe and the divergent design into the air box on that Mazdatrix picture. Do you see any of our forum members making something like that for their "CAI" projects? No, it's almost always some really long piece of small diameter piping with multiple bends, or it's some restrictive air box that has tons of "heat shielding" around it and very little access to inlet air. Granted, I'm not a big fan of dryer duct on intake systems, but at least they designed the majority of it pretty well.

Originally Posted by Roen (Post 7434086)
I'm still unsure how much a filter impacts the ITB setup. A lot of S2000 guys say that their filter robs upwards of 40 hp from their ITB setup . While that number is a bit high to be believable, alternatives do exist such as mesh screens or running open ITB's. While that last option isn't recommended for the street, a lot of S2000 guys run it without problems. I'm not as brave, and can't wait until I hear one of them complain about sucking in a large rock that made its way into the engine bay, or something similar. Still, no filter restriction does mean max power.
I have reviewed independent testing data on various engines, and it seems that an unfiltered carb tends to flow a little better at lower rpms, but a well-designed filter seems to increase flow at higher rpm's. I am sure the particular application makes a lot of difference though. While I am not very familiar with the S2000, a 40hp loss sounds like a very inflated value on an engine that I assume only produces about 300bhp.

Roen 10-18-07 06:49 PM
I don't see how a filter would increase flow at higher rpm's...i mean, isn't a filter a restriction, even on an ITB?

I still think using a box similar to mariah's, possibly made of ABS plastic for better heat shielding capabilities and extending the stock plastic air tube into the airbox would make for a decent cold air setup on a stock induction system.


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