Custom airbox options

[CMF_deNs]

Well it's time to change my air filter, and i'm a bit torn between what I should do.

Currently i've got cisco's old intake on it:

http://www.micra.com.au/technical-articles/compact-cold-air-intake.php

However, i've got a spare pod which aaron gave to me a while back. The main reason i've hesitated to go pod is that I may lose responsiveness with acceleration. The main reason I want to move away from the current setup is because the filter is getting dirty pretty quick and the low pickup point isn't ideal for keeping crap from getting in there.

I've checked it regularly and sand and even the occasional leaf gets trapped behind the filter, but today's check on it had a couple of things sitting on top of the mesh on the throttlebody. A couple of weeks ago while driving the car stuttered twice, but hasn't done it since. I want to prevent damage to the AFM so a pod is tempting. I've had an idea though.

I'm quite tempted to have the pod sitting in a cutout of the blocker panel behind the front grill, have a 3" stainless pipe going over the engine (possibly with heat shielding) and taking the bottom part of the stock airbox, and fabricate a metal airbox with a 3" inlet on it to have over the throttlebody.

Not sure about heat soak into the airbox, but would it be worth attempting?

Edit: Oh and also - I'm not sure if what i've got is an oiled filter or not. I've been told I can wash out the oil from those kinds of filters with water+detergent; is this true?

---dens

 

[CMF_jay22]

yes you can wash those filters.
i have found with my setup
its a hell of alot louder
more response with accelerator
but to anyone with a bit of car knowledge you can clearly see the pod at the front.
whitch i know its not legal to have.

does any one know what you have to do to make it legal
ie make it enclosed or a shield around it?

 

[CMF_deNs]

Wha? Pods aren't illegal. You're allowed to have one intake modification AFAIK. As long as it's secure there's no issue.

You can have a shield if you want but it's not required.

---dens

 

[CMF_jay22]

oh sweet

don't know where i heard that they weren't legal

 

[smidge]

its an emissions thing, they can bust you on it in NSW if they feel the desire, depends how stingy the person inspecting the car is

 

[CMF_deNs]

Legalities of pod filters aside - anyone have any thoughts on the airbox/filter idea?

---dens

 

[CMF_maat]

there is always this option.. i will be looking into it in the near future to improve my intake

http://images.google.com.au/images?...&resnum=0&ct=result&cd=1&q=k&n+apollo&spell=1

this is my current setup

 

[CMF_maat]

whole bay

 

[CMF_maat]

and this is my coolant bypass so my ga15 TB doesnt heat up with the coolant

 

[CMF_Yom]

Forever stealing my ideas maat.

lol

 

[CMF_deNs]

Got a couple of questions about that setup maat.

Considering the filter is right on the TB, won't that affect throttle response? I've seen those mushroom filters used before, but hadn't considered them because i'd read that they were generally pretty poor for filtration.

I can't see that K&N apollo thing fitting under the bonnet, especially with a strut brace.

---dens

 

[CMF_Yom]

Any foam filter will be inferior to a high quality paper filter like the genuine nissan filters when it comes to filtration.

Regardless of whether its oiled or not.

Needless to say, I'm a paper boy. Won't catch me using anything other than a genuine filter in anything anymore!

 

[CMF_maat]

throttle response on my car is second to none IMO, im working on the theory that having the filter on the end of a long tube in the engine bay creates a dead space in the intake therefore not having much suction power at the filter thus creating poor throttle response? the filter i currently run is a HKS unit and has proved itself to me and the C.A.I system im using feeds it enough cold air for me to drive it on say a 30* day for a good distance at running temp, pull over and it be cold..

the apollo set ups are ideal for the micra IMO in that it should fit fine under the strut brace ( the pipe that is ) and then you could mount the filter in its enclosed unit behind the grill like some other members have and combat the problem of heat soak from the extractors etc

and tom. i stole them fair and square, maybe not from you.. i just made them happen

 

[CMF_maat]

Yom WROTE:

"Any foam filter will be inferior to a high quality paper filter like the genuine nissan filters when it comes to filtration.<BR><BR>Regardless of whether its oiled or not.<BR><BR>Needless to say, I'm a paper boy. Won't catch me using anything other than a genuine filter in anything anymore!

thems sounds likes the words of a man whos fed-up with the headaches modding a car can cause

in all honesty thats a smart move but im really not fussed using the after market oild hks unit cause my cars my hobby if me running that meens me having to pull off the TB unit every 6 months and clean the AFM sensor and everything so be it

 

[CMF_Yom]

Not the AFM i'm worried about, moreso the engine's internals.

But thats not much of a worry when second hand engines are so cheap i guess.

 

[CMF_SSUK]

.

Yom WROTE:

"Forever stealing my ideas maat.<BR><BR>lol

That coolant bypass idea has been around since the good old Nissan British Touring Car Championship days when they ran 2.0L 300bhp NA Primeras.....the idea was stolen from them, as it's what they used to extract more torque from the engines, particularly off the line. There were other modifications used but they required significant design changes to the engine, which were not really feasable to bring over to the average CG13DE road going car.

 

[CMF_tris]

how does not cooling your tb increase torque??

 

[CMF_Yom]

As it is colt air intakes on the CG13 are useless as the TB heats up to engine temp heating some of the air that moves through it.

Personally I think removing the temp bypass in warmer climates is a good idea as it will help keep the AFM electronics cooler. As it is they are exposed to temperature variations they're not really meant to operate in.

This is probably why they fail so regularly.

 

[CMF_maat]

youd be suprised how much the TB DOESNT heat up with the bypass even though its in the engine bay you can thrash your car for a good drive stop and put your hand on the whole unit and its not warm

 

[CMF_mipcar]

So maat, to clarify. That bypass is a job that can be done to the standard Micra T/B?

Mychael

 

[CMF_Yom]

Sure can.

Disconnect the 2 pipes going into the thermal wax pellet and join them using an alloy pipe. Clamp the pipes and its set. All you have to do then is bleed the system of air.

It may however encourage a high idle.

 

[CMF_maat]

^^ what he said + you may need to adjust your idle when its at running temperature so its back to around 800rpm+/- and when its cold you have to push ever so slightly on the accelerater for the first 3-4 seconds to keep it from stalling, then it you can take your foot off and it will be fine, not a great hassle for such an easy mod

 

[CMF_jay22]

this mod sounds simple and good. but what the benefits? is it only torque? and how much more?

 

[CMF_Yom]

Throttle response, better driveability, longer AFM lifespan to name a few.

Only downside is cold start idle will be crap and it'll be like trying to keep a carby car running while its cold.

This will really only affect people in cold climates.

 

[CMF_deNs]

No issue for me, the ol' civic was the good old manual choke with the carby Sounds good though.

Might start making up the airbox sometime soon and get some tubing made up for the intake soon.

---dens

 

[CMF_maat]

jay22 WROTE:

"this mod sounds simple and good. but what the benefits? is it only torque? and how much more?

yeah its "only" torque but i think people quite often forget torque is equally as important as power.. its not always about how much hp you have.. --- torque gets you there, power keeps you there ---

 

[CMF_deNs]

If I had to choose between the two, i'd rather the kick in the pants kinda feeling than the "oh, i'm finally going fast now" feeling.

---dens

 

[CMF_jay22]

sounds like i should give it a go.

 

[CMF_SSUK]

Well I'm from the UK and I don't have any idle problems when it's cold. The car does need some initial setup but once set it starts and idles perfectly and doesn't require any additional throttle to get it running.

The only thing you will notice is some fuel dropout on the bottom of the plenum, this gets worse with cams due to the overlap and a portion of reversion at low rpms. The other thing is this setup makes passing emissions testing harder, but I simply plug the coolant lines back up again when it's needed and the car passes with ease.