CAI: Alien By Design

[alien]

Well, it's been just under a month since i installed my CAI. Have found that the fuel usage has dropped when driving it the same as i was before. But when i do need the power there's a bit more.

No sucking sound though, but that could be due to no gf, or more the fact that the exhaust hasn't been reworked yet or even due to the thickness of the pipe i used. You can definatly feel the suction if you stick your fingers over the CAI and rev the engine (by yanking the accelerator cable).

This CAI is designed for the VYs but can be adapted to other vehicles. However unlike the 2 hole mod or commercial CAI's this one causes the air to spiral into the airbox increasing the power you can get through (if you want a long explination look into why the K&N air filters create spirals). The aim of this version was also to keep it looking stock.


Anyways, here's how to make this one:

What you'll need:
* 90mm PVC Pipe
* Hot air paint stripper (or you could use a butane torch or even a hair dryer)
* File
* 90mm 90 degree PVC elbow
* Plumbers Cement
* 2Lt coke bottle filled with sand (beach sand will do)
* Hacksaw
* Drill
* Drill Bits
* Bumper Paint (i used black to blend in with my car and air system)

First thing to do is to cut a length of PVC pipe off to flare with the hacksaw (or a PVC cutter if you've got one). As for length, leave it a bit longer now, saves re-doing it when you cement it. Make sure one cut is straight but allow the other cut to be on an angle (IMPORANT). Angle will vary depending on length, but it only needs to be a slight angle with this setup (see pic below for guide). Make sure you also file both sides (inside and outside) of the PVC pipe to get rid of all the burrs. If you dont know what they are look at the pic below mine [Image courtesy of PinWire], but please note WE want the burrs on inside AND outside gone.



Next step is to grab your bottle and heat gun:


Use the heat gun to warm up the end of the PVC tube on an angle. If you warm too much of the PVC tube up the whole thing will go all floppy, that's ok, the coke bottle can fix that too. When the PVC pipe is all warm on the end grab it quickly and push it straight onto the coke bottle like below (you must act quickly as the PVC pipe can cool quickly and once on the coke bottle the Sand will draw away the heat quickly [that's what it's for as well as making sure the coke bottle doesn't distort]).


Tips: While on the coke bottle you can turn the PVC pipe around on the coke bottle to get a more spherical (and not lumpy) shape which is what you want
and
DONT use the heat gun on the PVC pipe while its on the coke bottle, this will distort the coke bottle shape!

You will end up with this (this was taken before i made it a bit smoother on the coke bottle again):


OK, now is the best time to check the length of the PVC pipe you've got. You want the pipe to be long enough to just sit right where the headlight wiring harness is (cool air is scooped up by the bumper to there). I dont have the length i've used as i didn't measure it! But if you judge by the picture below you can get a rough idea (the plumbers cement is a 125ml container available from any Bunnings store).

Next grab that PVC cement and your PVC elbow.


Inside the Cement is a brush, so dont worry, you dont need to get one... it's part of the lid.


Dry assemble it first so you know how it goes. If you also look at the pic od the dry assembled version with the cement (2 above) you'll notice that the thing leans towards the cement slightly. That's the best way to have the angle which has been flared. Apply the cement to BOTH the non flared part of the pipe and the inside of the PVC elbow and push them together quickly. Apply pressure for 30 seconds, then allow 5 minutes to dry. Dont worry about any cement leakege in the pipe, try to minimise it though.


Once it's dry, grab your bumper paint and spray the thing.


If you have no place to spray paint it without getting it everywhere, use a box from any shop. Many will happily give you one for nothing.


Allow to dry.

Now, onto the air box, remove it from the vehicle (disconnect the MAF and the temp sensor on the airbox, then remove the standard air intake and then remove the wire clips around the airbox, then the whole airbox). I had a fairly dusty engine bay which helped quite a bit. If you dont, just grab a marker and trace around where the pipe should go (refer to pic below). If it's dirty, just rub clean around the pipe leaving the dusty area to be cut (this works out to be more precise for a better fit). And yes, you want the pipe to be touching that bottom bit of plastic that sticks out a bit.


First drill a hole somewhere in the centre of where the pipe goes.


Next, grab a smaller drill bit and start drilling about 1-2mm from the edge of the "dust line". Sorry no pics here. If your drill dies from a low battery like the one i was using did (a little 12V cordless one) put the battery on charge and just grab a knife and cut straight towards the big hole in the centre from wherever you started and finished drilling on the outside.

Now, try fitting your pipe, if you've done a good job you'll find it wont fit. Grab out your file and start getting rid of the airbox plastic that way (and yes, get rid of the burrs). Every minute or so line up your PVC pipe with it and try to fit it so you know where to take more plastic from to get a good fit. once you get it nice and tight you'll find you wont need to even use silicon or any other sealant. It will stay and the air coming through the side is negligable. So you should end up with something like this:


No, we're not quite done yet though. In the VY's there's not enough clearance from the airbox to the guard wall. So that little bit of plastic that sticks out that we lined the PVC pipe up to has to be shortned. I shortened mine to 1-1.5cm (from memory). Just grab a hacksaw to do that, will save a LOT of time. Again file to make it look clean. When putting the air intake on, try to angle it down a little, helps get more air in.

Now all you need to do is put the air box back in the car (in the reverse you took it off). Leave the stock air intake too. 2 Intakes are better than 1!


Grab a beer, or whatever you drink and enjoy a great job.... or dont drink and have some fun. It may take a while for your car to get used to it and make adjustments to get the car running as well as it can. Just give it time, the VY's "learn".

Here's just some pics of the job:

Looking at the CAI pipe.


Again, with a bit more showing how it goes there.


How close the flared end sits where the wiring harness at the headlights is.


All back together with the CAI.


And another view all together.

[LightningVP]

Well that's explains how you did it...Nice work ^_^ A hard time for a cop to realise you have it...Took me a while to see it in there

[DUK13Y]

Good write up mate.. might give it a go.

[Junny]

Well that's explains how you did it...Nice work ^_^ A hard time for a cop to realise you have it...Took me a while to see it in there

huh? ur not allowed to do this stuff? o.O
or is it like turbos and S/Cs how you have to get a engine certificate?

[alien]

LOL, no problem. I havn't changed air filter yet, so it's still stock, but notiecable.

Also, just in case people want to point out the PVC pipe with the spiral in it.... DON'T use it! It will not help this design, that's designed for water not air!

This deisgn is fairly cheap, i only had to buy the paint ($10 from Repco), $2 or $4 for the elbow and the cement ($5ish from memory) [but theres plenty for any future tasks you need it for].

huh? ur not allowed to do this stuff? o.O
or is it like turbos and S/Cs how you have to get a engine certificate?

New P Platers in Victoria arn't allowed to modify their vehicle to increase performance, this increases performance and is therefore illegal for them! But if you keep it stock [or more to the point, stock looking], there's less for a cop to pick on.

[SAV_117]

hey mate sweet write up might give it a go soon

[PaulSV6]

Nice write up mate,
Looking at the size of that hole, i could have made mine bigger.

[alien]

You used a 70mm pipe in yours didn't you? You'll probably notice more of a growl with the smaller pipes, but that's due to it restricting the actual air it can get in.

Comparing mine to other ones mine's definatly quiterer (you can still hear it a little if you listen for it) than others, but you can feel it pulling in quite a bit more.

[PaulSV6]

You used a 70mm pipe in yours didn't you? You'll probably notice more of a growl with the smaller pipes, but that's due to it restricting the actual air it can get in.

Comparing mine to other ones mine's definatly quiterer (you can still hear it a little if you listen for it) than others, but you can feel it pulling in quite a bit more.

Yep, 70mm mate. Thats true.

[stocky]

New P Platers in Victoria arn't allowed to modify their vehicle to increase performance, this increases performance and is therefore illegal for them! But if you keep it stock [or more to the point, stock looking], there's less for a cop to pick on.

are you a new P plater? if so, the supercharger will be more of a problem than a CAI

[Skooby]

Although if you are a new P Plater, ANY engine mod is a big NO NO.

Not worth losing the points on your P's.

Just get an OTR and tune, for the $$ nothing will beat it

[DUK13Y]

an otr on a v6?

[alien]

are you a new P plater? if so, the supercharger will be more of a problem than a CAI

Point taken. Thank god i'm not on the new system! However Vicroads can grant exceptions in certain circumstances to those rules.

But you can do this on a 6 cylinder too, which means the new P platers could hide a small mod like this, especially if the car is black.

I personally think that OTR's arn't as effective, well, theoretically, but i have never compared OTR to this mod so i can't support any stance.

[HRVATSKI_VOJNIK]

Point taken. Thank god i'm not on the new system! However Vicroads can grant exceptions in certain circumstances to those rules.

But you can do this on a 6 cylinder too, which means the new P platers could hide a small mod like this, especially if the car is black.

I personally think that OTR's arn't as effective, well, theoretically, but i have never compared OTR to this mod so i can't support any stance.

i don't know if they said anything about additives
i remember soon after i fixed up my car and put some pro octane booster,
(cops can't prove anything unless they find the bottle. i guess)

i should have a crack at making it, don't have much space to hide it on my VS, so I'll just put it in a notable area and can say i got a supercharger inside the air box for protection with themo padding so i don't need an inter cooler

surly there's some one who'd believe it

but on a serious note, I'll have a crack at it in the near future

[stocky]

Point taken. Thank god i'm not on the new system! However Vicroads can grant exceptions in certain circumstances to those rules.

But you can do this on a 6 cylinder too, which means the new P platers could hide a small mod like this, especially if the car is black.

I personally think that OTR's arn't as effective, well, theoretically, but i have never compared OTR to this mod so i can't support any stance.

oh so youre not on the no supercharged/v8 engine rule? if so, you shouldnt really have an issue with adding a pipe onto your intake

[alien]

oh so youre not on the no supercharged/v8 engine rule? if so, you shouldnt really have an issue with adding a pipe onto your intake

I never said i did. I did comment that it was nice and looked stock though. Nothing about it being an issue! :S

[TrEnNaVY]

good write up bud. ill be giving this 1 a shot soon

[Ozzie]

I was wondering what you were goin on about when you said you modified it

nice clean job too. well done!

[alien]

Ozzie, i thought i sent you the link to it when i posted it! My bad! :P

Thanks, definatly looks the part in my vehicle! Still havn't changed the air filter yet though, waiting until the major service for that, then i'll be putting in a K&N filter. Then report on what that does too.

With the Supercharged engine you dont really hear the sucking noise. The main time when you would be when the whine of the supercharger is overpowering any sucking sound. Although i should have enough air coming in to make the sucking noise less noticeable. A 90mm pipe with the Holden intake should be feeding it enough to decrease the sucking noise. Sucking noise would theoretically be made when there is not enough intake room so the air is compressed a little and more is forced in that same area. Same effect as if you put a smaller nozzle on a vacuum cleaner. However with the noise you'll notice it's not being as efficient as it can be. [There you go for whoever asked me for that, can't remember who you were i was going to post it]

[D3CID3R]

Nice write up Alien. Definitely on my to do list. Make fiddle with a box from the wreckers tho :-p. Just quickly do u mind clarifying what you mean by cutting it on an angle before flaring??? Is this so it fits better in the engine bay?

[D3CID3R]

Just finished it on my might.. gonna modify it a bit.. what u reckon Cold Air Intake (VY) - D3CID3R Style

[alien]

I reckon it looks good, did you feel any difference?

I just installed my K&N Panel Filter the other week, and there is much more air flow going into the engine as registered by the MAF. Yes you can hear it too, but the supercharger has also changed it's whine as well. Doing both has definatly been an advantage, dont know if i also stated but the factory intake had also been modified to have a larger hole. Either way i know both intakes are taking in air as you can put your hand in front and feel it sucking in.

I have also updated the pictures in this HowTo so that they wont go offline for months like they have been the past few months. One picture though i have no control over.

[D3CID3R]

can definitely hear it sucking in.. even cars next to me.. since the mod i can notice better mid range pickup

[alien]

I think other cars can hear mine too, but when its going along the supercharger usually drowns it out. I found my low range picked up more and mid range to a small extent, mid range picked up a lot more with the newer air filter though. I guess that's due to the differences in the engines from the 3.8L to the Supercharged variant.

[VYute04]

i hell want to give this MOD a shot but im scared im gonna **** up my current air intake box, and is 90mm the only size u can use?