Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

CAI: Alien By Design

alien

Member
Joined
Nov 5, 2008
Messages
915
Reaction score
19
Points
18
Location
Tullamarine, Vic
Members Ride
03 VY Supercharged 3.8L
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.
10-01-09_1950.jpg

lb_02_burrs.jpg


Next step is to grab your bottle and heat gun:
10-01-09_1951.jpg
10-01-09_1952.jpg


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]).
10-01-09_1957.jpg


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 :thumbsup:
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):
10-01-09_1958.jpg


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.
11-01-09_1848.jpg


Inside the Cement is a brush, so dont worry, you dont need to get one... it's part of the lid.
11-01-09_1849.jpg


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.
11-01-09_1854.jpg


Once it's dry, grab your bumper paint and spray the thing.
11-01-09_1901.jpg


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.
11-01-09_1900.jpg


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.
17-01-09_1500.jpg


First drill a hole somewhere in the centre of where the pipe goes.
17-01-09_1503.jpg


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.:yeah: So you should end up with something like this:
17-01-09_1602.jpg


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!
17-01-09_1623.jpg


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:
17-01-09_1625.jpg

Looking at the CAI pipe.

17-01-09_1626.jpg

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

17-01-09_1627.jpg

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

17-01-09_1628.jpg

All back together with the CAI.

17-01-09_1629.jpg

And another view all together.
 
Last edited:

LightningVP

Donating Member
Joined
Sep 15, 2008
Messages
673
Reaction score
15
Points
18
Location
Victoria
Members Ride
VY II 5.7 SV8
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 :p
 

Junny

purrrrrr
Joined
Jan 14, 2009
Messages
549
Reaction score
2
Points
0
Location
Geelong
Members Ride
VUII Maloo + shitty painted vp
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 :p

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

Member
Joined
Nov 5, 2008
Messages
915
Reaction score
19
Points
18
Location
Tullamarine, Vic
Members Ride
03 VY Supercharged 3.8L
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.
 
Last edited:

SAV_117

Donating Member
Joined
Jul 26, 2008
Messages
1,177
Reaction score
11
Points
38
Members Ride
VE V8 Calais
hey mate sweet write up might give it a go soon
 

PaulSV6

CHE Tuned 156.8rwkw
Joined
Jun 10, 2008
Messages
1,384
Reaction score
11
Points
0
Location
Castle Hill
Members Ride
VZ SV6 M6, MY10 VE SV6 Sportswagon & MY03 XC SRI
Nice write up mate,
Looking at the size of that hole, i could have made mine bigger.
 

alien

Member
Joined
Nov 5, 2008
Messages
915
Reaction score
19
Points
18
Location
Tullamarine, Vic
Members Ride
03 VY Supercharged 3.8L
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

CHE Tuned 156.8rwkw
Joined
Jun 10, 2008
Messages
1,384
Reaction score
11
Points
0
Location
Castle Hill
Members Ride
VZ SV6 M6, MY10 VE SV6 Sportswagon & MY03 XC SRI
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 Member
Joined
Jun 14, 2005
Messages
5,040
Reaction score
80
Points
0
Age
36
Location
Melbourne
Members Ride
1995 HSV Clubsport T5, 1991 VN Berlina
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
 
Top