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Stock Air Box Vs. Cone Intake.... how can I get the best of both worlds?

7151 Views 21 Replies 11 Participants Last post by  shift_of_legend
Just recently I put a cone filter style WAI on my SE-R, but I’ve been less than thrilled with its results.

Really, the cone filter looks cool and it sounds cool and anything above 5,000 RPM I’ve noticed it really improves performance but this all comes at a price. The bottom end of my power band now suffers. I have trouble getting a decent launch in the 2.5k RPM range. It seems like anything below 3 grand and the car is a slug.
As much as I love to break out with a 4,000 RPM launch at a green light… I have to admit not every intersection needs to see me rev so high nor does my ageing transmission need the beating.

I just wish there was a happy medium to be achieved. I realize the air box in our cars allows for better low-end response but top end performance is lacking.
The cone filter has excellent top-end performance but now the bottom-end falls short.

Is there anything I can do to resolve this problem? I fear my only choice will be to go back to the old air box setup. :(

Answers… opinions… experiences…?

Should I switch to a CAI setup?
Should I try a different cone filter?
Should I try to modify the stock air box to allow for better top-end performance?
1 - 20 of 22 Posts
go with a cai
i always just cheese grader mine and my friends stock air boxes (cut or drill holes) its free and that way i can still pass inspection. I can keep drilling holes till the performance i am aiming for is achieved
black_ser95 said:
go with a cai
Do you think this will solve my problem? I'm no stranger to installing a CAI but what about the bottom end? Will this solve the issue and give me lots more bottom end like I was getting with the original Air Box?

It's been my experience CAI's help but still lack in the "low" bottom end power.
Can you support your suggestion with any relevant facts (proven or personal experiences)? :)


Slacky said:
i always just cheese grader mine and my friends stock air boxes (cut or drill holes) its free and that way i can still pass inspection. I can keep drilling holes till the performance i am aiming for is achieved
So are you saying drill a bunch of holes in the lower portion of my air box to open it up some for a little more air flow?
basically yea, i havent done it to mine as i have not finished my gti-r swap yet but i most likely will drill roughly...... 12 holes if i even use the air box, idk what im gonna do for a intake with my turbo
if you want bottom end pull, go with a cai.
Slacky said:
basically yea, i havent done it to mine as i have not finished my gti-r swap yet but i most likely will drill roughly...... 12 holes if i even use the air box, idk what im gonna do for a intake with my turbo
Using the stock air box with a GTi-R swap would kinda defeat the purpose of the swap in the fist place wouldnt it?

As for putting a Cone air filter on and LOSING bottom end. You might want to try tuning your car up or somthing. I dont see how you lost bottom end just by instaling a filter. If anything you should have gained throttle response and maybe like 2-3Hp across your whole RPM band.

Anyway if you feel like it really is the filter that its killing your bottom end for some reason and want the best of both worlds...Picture your stock intake box....When you go to change the filter, the top part of the box unclips and you have access to the filter. Take that bottom portion of the Air box and throw it out(you have to unbolt it from the car). Use string, Zip ties, or whatever else you want to use and tie the filter the the top part of the box. Walla. You have an open filter air box.
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Ok ok...

I'm so irritated by the loss of power that I've decided to swap back to the old Air Box. I hear you guys saying CAI but I'm just not ready to go that route as of now. I agree the WAI should have solved all my problems and not reacted this way but for some reason it does. Once I re-install the Stock air box I'll test it out both ways, bottom in tacked and bottom removed. This should help me understand if I'll need to modify the bottom portion of the air box to allow for more air.

I realize this WAI problem seems highly unlikely but this is what I've been experiencing over the last 2 weeks since it was installed.

- Forced to shift around 5,000 RPM if to get any pep in performance.
- Any shifting under 3,000 RPM bogs down so bad it's not worth it.
- I've burned through a tank of gas but only received 1/2 the mileage I use to get.
- Two tanks of gas and I know for sure the current tank is good quality high octane. No lag in spark or timing.
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Ok, here's what I did...

When I re-installed the stock air box all the low-end power was back! The power was consistent in the low RPM's. I found I could gracefully achieve plenty of power in the 2.5k RPM range. All I can say is, YES!
It feels like the stock filter smoothes out the power band too. The lows are very predictable and smooth (nothing like I was experiencing with the cone filter). It was almost as if the cone filter was giving unpredictable amounts of air (too much air) all at once. I wonder if in order to receive a constant flow the engine had to be running higher RPM's to compensate (in an attempt to keep the flow constant). What ever the case may be I'm just happy my car drives more like it should now.


When I was installing the filter I found it was possible to mount the air filter upside-down so it stays in place without the use of the lower box. I also noticed with the filter mounted open like this it makes that really cool intake sound like it did with the cone filter. :thumbup:

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very nice, my buddys subarud does that too, runs like crap if theres to much air flow, the maff goes all crazy like so we modded the air box cus his couldnt flip upside down like that, very mc gyverish of u to figure that little mod out, i like it and im happy u got the throttle response ua re lookin for

as for using a factory gtir air box with a gtir swap defeating the purpouse of the swap?... .. thats just silly considering i went n/a to turbo soooo a air box really wouldnt defeat the purpose now would it, i went from 140 to 234 crank hp stock vs stock
Slacky said:
very nice, my buddys subarud does that too, runs like crap if theres to much air flow, the maff goes all crazy like so we modded the air box cus his couldnt flip upside down like that, very mc gyverish of u to figure that little mod out, i like it and im happy u got the throttle response ua re lookin for

as for using a factory gtir air box with a gtir swap defeating the purpouse of the swap?... .. thats just silly considering i went n/a to turbo soooo a air box really wouldnt defeat the purpose now would it, i went from 140 to 234 crank hp stock vs stock
You miss understand what im saying though. To me if you go through all the trouble of swapping motors for the sole purpose of more HP why put the stock air box back on.
My friends N13 Sentra Sti (Pulsar SSS) has Cams, Header, Exhaust, Flowed Head. He removed the standard airbox and replaced it with a cone filter. The car was going like a demon for about a week, then the power died and the car started jerking and had no power, then he refited the standard airbox back, and voila! The car performed great again.

Any Ideas?

BTW, this is what the SA Sentra Sti looked like before being replaced by Almera's. Sentra/Sabre STi/Gxi SR20DE
How long did you have your WAI on?? My friend put a WAI on his 01' SE and had a loss in bottom end untill, what I can figure, the ecu adjusted to the new amount of air coming in (took him 500-600 miles).
yea... the computer re- ajusts itself to sudden changes in new cars for instance everyone knows about that tornado air intake thingy well anyway it does work untuil the computer adjusts, only good for carbed cars just another situation where modern cars dont like bolt ons without computer adjustment
you may lose a little bottom end in the initial launch, but what you gain afterwards more than makes up for it. There are plenty of dyno charts showing just that.

What kind of filter did you use with the WAI?
CrashSEntra01 said:
How long did you have your WAI on?? My friend put a WAI on his 01' SE and had a loss in bottom end untill, what I can figure, the ecu adjusted to the new amount of air coming in (took him 500-600 miles).

True...It does take some time for the ECU to adjust.. 500-600 miles seems a bit excessive.. more like a dozen normal drives as an estimate.
Sounds weird to me, but I do believe you. When I started modding my last 200 and installed a JWT pop-charger, I didn't notice any difference in low end power at all. Above 4500, you could feel a difference, but the bottom end felt the same. Also, I could launch the same as with the OEM airbox.

A CAI would help you out, but unless you have a header, that would be the best way to open up the whole powerband. My biggest gains in power were when I installed the header and after installing cams. Both made it feel like a whole different car.
Are your B12/B13/B14 SR20DE's fitted with Lamda/O2 sensors? If it is there is a chance the ecu would adjust itself but without it what other reference would it have to change the mapping? Our N13/N14 Sentra's didn't come with O2 sensors so I don't think the ECU would self adjust.
myoung said:
you may lose a little bottom end in the initial launch, but what you gain afterwards more than makes up for it. There are plenty of dyno charts showing just that.

What kind of filter did you use with the WAI?

I lost so much bottom end that is wasn't even worth the mod. :(
And because I had to stomp it everywhere I go my gas mileage was in the crapper. In the end it just wasn't worth it so I switched back.
Immediate response was noticed from there after! (Excellent gas mileage too)
I'm actually considering reversing my filter setup (pictured) back to completely stock mode. Performance is good but I think it may be even better with the airbox back in its stock position.

It totally boggles my mind as to why the car loses power with more air?
I do have the Stillen 4 to 1 header installed but I would think the header is helping the situation more than hurting it.

Oh, and the filter was just some generic brand cone filter.
I installed a cone filter too, a genric one, and i did felt some better response at first, but now after 4 months, i`m starting to feel that the gas milleage it`s starting to suck, I do have excelent response after the 4,500 rpms, but lower than that, I have to push the car to make it move nice, it`s like havy
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