Restriction in the stock air intake - pictures

GSB · August 27, 2003, 13:09

Just for reference purposes, here is a picture of the air restriction in the stock intake system that markiii has occasionally mentioned in the forums.

The black pipe is the engine air intake, that leads from the side intake vent on the left, and flows into the air filter on the right, as you can see there is a marked decrease in pipe diameter at this point.

Why its there, is a mystery to me...

If you want to look for yourself, this little pipe lives under your left side rear light cluster.

Anonymous · August 27, 2003, 13:20

air restriction = BAD...

...do what all the guys in the know do ...

...just remove it - thats what SteveJ and a couple of others have done (doing mine soon) will make your car sound like you have an APEXI on it! s:D

s:D s:D

s:D

GSB · August 27, 2003, 13:26

Quote from: "krisclarkuk"air restriction = BAD...

...do what all the guys in the know do ...

...just remove it - thats what SteveJ and a couple of others have done (doing mine soon) will make your car sound like you have an APEXI on it! s:D s:D s:D s:D s:D s:D

Unfortunately this means your engine is breathing air from the engine bay, and thats bad too. It gets very HOT in there...

Anonymous · August 27, 2003, 13:29

very true... which was my initial worry, but i think steve was running it like this on his old car and never had a problem... not sure if he used the pocket logger to check if things were going funny or not...

IIRC, Steve was talking to your exhaust guys about some non-restrictive pipe to replace the one that is currently there... that would be interesting...

Anonymous · August 27, 2003, 14:13

I'd be worrying less about immediate damage (that's been shown not to be a problem), but more about longer term problems.

Anonymous · August 27, 2003, 14:16

Surely it would be more prudent to stick an induction kit on and actually replace the stock air intake rather than just take it off?

Anonymous · August 27, 2003, 14:19

Mine came off at JAE and went back on again as soon as I was home, once the engine gets hot I don't think it would do much anyway. And it drank fuel like it was a mutant fish.

The stock air box is very very good, some of the replacement induction kits even dropped in power when people on SC ran tests. The people I know at Pipercross said they gave up because they couldn't make one better than the stock box.

The only problem with the stock box is its position, it really would probably be better behind that battery.

Anonymous · August 27, 2003, 14:23

Quote from: "jag"Surely it would be more prudent to stick an induction kit on and actually replace the stock air intake rather than just take it off?

yes your right, but then you are still going to be sucking in the same hot air as if you just removed the pipe. I would not do this with the stock air filter in, i would have put something like a K&N panel filter in or something for that extra piece of mind.

I dont think its really a performance mod, but it does make the engine sound nice (a cheap mans apexi if you will!)

anyway, everyone stop having a go at me about it... it was just a suggestion... *goes off to cry in corner* s:cry: :cry: s:cry: s:cry: :cry: s:cry:

s:wink: :wink: s:wink:

Anonymous · August 27, 2003, 16:09

If you look closely you will see that the black pipe acually stops before it reaches the side intake. It is picking up air from just behind the wheel arch!

I took the pipe off my old roadster and replaced it with an aluminium suction hose connected directly to the hole in the box where the old black pipe went in.

I then ran the tubing over the wheel arch space where the old one stopped and directly up against the mesh on my side intake!

The results were awsome! It acted like a forced / ram air feed, increaded my torque on dyno results and you could hear the air being sucked in every time you put your foot on the gas!

Anyone else tried that yet?

Anonymous · August 27, 2003, 16:12

Quote from: "bluephoenix"<snip>you could hear the air being sucked in every time you put your foot on the gas!</snip>

I hear that anyway... lovely lovely! s:D

s:D (must be my HUGE ears!)

Anonymous · August 27, 2003, 16:16

Quote from: "bluephoenix"The results were awsome! It acted like a forced / ram air feed, increaded my torque on dyno results and you could hear the air being sucked in every time you put your foot on the gas!

Anyone else tried that yet?

Sorta like a poor mans Supercharger?

Anonymous · August 27, 2003, 16:26

Exactly, except it only cost me £10 for the hose!

How has everyone else managed it?

My new car (pictured left) has a hks induction kit but if the filter is positioned in the engine bay I may do the same and run the pipe directly to the cone to cool it.

What you reckon?

Slacey · August 27, 2003, 17:45

Quote from: "bluephoenix"My new car (pictured left) has a hks induction kit but if the filter is positioned in the engine bay I may do the same and run the pipe directly to the cone to cool it.

What you reckon?

Might work nicely. Evidently from your previous post you have tried this sort of thing before, if you do give it a go, let me know - I might try something similar with my Apexi.

Tem · August 28, 2003, 06:24

Quote from: "GSB"Why its there, is a mystery to me...

So TRD could make an aftermarket part for it s;)

s;)

Just joking, but I think they have a bigger pipe to replace that one...

markiii · August 28, 2003, 07:58

yep they do and it's around $300

Jap GT300 · August 28, 2003, 13:50

QuoteGSB wrote:
Why its there, is a mystery to me...

I remember a while ago this was discussed on SC and they came to the conclusion that the pipe runs thin to create turbulence and chuck the air out across the whole of the filter.

I don't know if this is true but I have heard of similar things in some CAI pipes. Manufacturers place notches or simlar at different points to create turbulence.

SteveJ · August 28, 2003, 14:15

Quote from: "Jap GT300"
QuoteGSB wrote:
Why its there, is a mystery to me...

I remember a while ago this was discussed on SC and they came to the conclusion that the pipe runs thin to create turbulence and chuck the air out across the whole of the filter.

I don't know if this is true but I have heard of similar things in some CAI pipes. Manufacturers place notches or simlar at different points to create turbulence.

One thing I found with my old roadster was in the winter it was slightly more reluctant to start if it was really cold and the elbow was out. This would seem to indicate the narrow section of the pipe helps to choke the engine for cold starting as with the elbow back in it was fine.

Just my 2c worth

Anonymous · August 29, 2003, 17:40

On a recent post discussing getting a ram air effect from a pipe fed from the side intake it was said that there is actually a negative pressure gradient in this area. This basically means that air is not being forced into the pipe but rather still being sucked from the intake stroke of the engine. To get any real ram effect I think we would need to extend the side ducts as per a Clio V6 - and as Greekspider has done already.

Jap GT300 · August 30, 2003, 11:12

Or you could buy a GT300 s:wink: :wink: s:wink:

Seriously though I think R-Spec make Side intakes that draw air to the intake ducts.

Anonymous · September 16, 2003, 14:46

I replace the stock plastic tube by a flexible aluminium tube like this
http://users.skynet.be/fa444545/MR/photos/Intake%203.jpg

The result sounds a little bit different, and may be the engine breathe better! but may be it's an idea!

Comer · September 16, 2003, 14:54

Does anyone know the part number for the 'elbow' part of the stock air box?I'm interested to see how much Mr T charges for them.

I can always check for the number once I get home on the one I removed from my car, but if anyone has the part number handy before 5pm then I'm going to call Mr T.

Thanks

GSB · September 16, 2003, 14:59

According to the parts list I've got it's 17751-22050.

Comer · September 16, 2003, 15:06

Cheers Grant. That retails at Mr T for £17.48 incl. VAT

GSB · September 16, 2003, 15:20

Quote from: "Comer"Cheers Grant. That retails at Mr T for £17.48 incl. VAT

In other words, cheap enough to experiment with cutting out the restriction, replacing it with some equal diameter tube and seeing if any improvements come of it? Interesting...