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How to CAI for stock air box on r32 GTST


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Hi Everyone,

I've just recently done a cold air intake upgrade for my r32 GTST so I thought I would share the ideas around and give some tips and hints.

Most of my ideas have been compiled from standing on the shoulders of other great people on forums so you may be able to find similar stuff elsewhere. There is a thread on CAI in this forum but it is more concerned with a partition for pods, not for stock air boxes, so please dont get these two confused. But, you can adapt some of the ideas from this also.

Summary:

Improvement - Excellent (perfomance much livelier)

Cost - NOTHING

Time - 2 hours (i'm an office worker, should take mechanics who know their stuff about half an hour)

Tools - Phillips Screwdriver, 10mm & 8mm socket & 1/2" Socket set, with screwdriver style 1/2" Socket Driver, something to cut with (blade), and zip ties.

Anyways, here is the details..

Theory first..

Intake air must be as cold as possible. It must also have the freest flowing route into the engine possible. Therefore, any intake mods must not take in hot air or restrict flow as you are defeating your purpose. ie. Dont just do one, always do both.

Therefore on an r32, the standard air box takes in cold air quite well. The only thing is, the air box is quite restrictive..

So, lets have a look. See Pic 1. It shows the standard air box setup as it comes from stock. Its taking a massive loop and gets its air from nowhere. It has no good means of refreshing itself with new air, its tucked up behind the headlight and everything else.

You can then see the intercooler air guide is equally bad. See pic 2. It should be allowing the freest flow possible through the intercooler, but its intake hole is just as small as the core, so does no real good in flowing air, all it does is shield the cooler from the heat coming off the intercooler pipe. BUT - its the pipe after the intercooler not before (so if you think about it, if the cooler's doing its job, this pipe should be relatively cool anyway..) So I decided to get rid of the intercooler air guide too.

Ok, so. How to remove these things and what to replace them with.

1. Remove passenger side headlight. There is 4 (size 10mm) bolts holding the headlight on. This is the hardest part of the job, so dont get disheartened when this takes a while. 2 are behind the blinker. Remove blinker by screw between it and headlight, then pull forwards, takes a bit if jiggling then comes out. Unbolt 2 nuts holding headlight. Then, there is a bolt behind some wiring on the metal behind the headlight. You should be able to tell where it is but the plastic part of the headlight that leads to it. Lastly (and this is the real pain) is the 4th one. Its located next to the radiator, and there is 3 bolts parrallel going down next to the radiator. Its really really hard to get at, so I had to take the front intercooler pipe off to get at it (the rubber hose clamps need an 8mm socket or spanner). I used a socket set with a 1/2 inch drive ratchet and extension to loosen it and then a screwdriver style 1/2 in socket to take it off.

2. Remove front of stock air intake. There is 3 (size 10mm) screws to do this, they are pretty easy to find. Ones on the top right in front of you and the other 2 are on the radiator side. Once undone take it off, should all come in one peice and end up looking like Pic 3.

3. Remove stock intercooler air guide. There are 4 (10mm) bolts holding this onto the cooler. you should be able to reach through the hole in the bumper and take them off. Then you need to drop down the plastic cover under the bumper area. To do this you need to drop the plastic cover under the engine a bit, maybe undo the middle, and 2 closest front ones. Then you should be able to see the plastic screw holding the intercooler area plastic in. Take that out, and gently take the plastic out from around the bumper and drop it down, till you can pull out the old intercooler air guide at the front.

4. Put the bottom plastic covers back onto the car same way you took them off.

5. ok, now this is where I needed to be creative. I wanted to get the cold air from the hole in the bumper where the intercooler air comes in from as this was the most logical place. There is a few ways to do this, some have suggested PVC guttering pipe (this would be pretty hard to mount properly) Another alternative might be flexible hose but that tends to be restrictive. As you can see from Pic 4 and 5, I have chosen spare radiator pipes. YES, Radator pipes off my dads ford that were sitting in my garage. Reason is: They were sitting around, and they are exactly the right shape and size needed.. So, I needed to use ones with 90 degree bends so they would fit behind the intercooler pipe.

6. I cut them with a blade so they were only just sticking into the air space from the hole in the bumper (so as not to restrict the flow to the intercooler too much - and also not as visible from outside - and not as close to the road to pick up dust). Also, cut at an angle so the air had large opening to come from. Then, I stuck them up into the air box hole together and zip tied them together. See Pic 5.

7. Put it all back together, how you took it apart

8. VERY IMPORTANT. Reset your ECU so your car can relearn how to handle the new/better air flow. You dont want it thinking its still got the crappy old stuff on there. Do this by removing the positive terminal and pressing on the brake then reconnecting. (and yes you will have to reset your clock after that).

9. Go for a drive (be amazed)

190823. Disclaimer... Yes there has to be one.. Make sure you check your air filter regularly and change it if neccessary as your new path for air will be picking up more dust and other bits and pieces than before.. A washable panel filter might be a good option.

Guys I would really like some feedback as to the usefulness of this post and if I should bother doing any more for future upgrades. Please reply to this post if you like it or have used it or anything I may have missed.

sounds the goods dude...

do u have a photo of the final product...

some very good theory and down to earth mods right there, all about efficiency..

top stuff

Yeh, I do, but you cant see anything, its all tucked in there behind the headlight. I will post it up anyways. Check back in a few days.

ahh cool....

Its just like a snorkel on the stock 33s... u noticed a livier response.

so infact, say you were at the strip... removing the passenger headlight would be even better.

I reckon with proper better CAI an easy ~20kw isnt impossible.

once again top stuff!

Thats an interesting way of doing it.. :P

I went the more bodgy way.

I cut a 100mm dia hole under the air box as close as I could before the wheel arch angle occurs.

I then used 2 x 45degree 100mm Dia PVC Corner Pipes.

One of the 45degree angles points to the front of the car in the inner of the front bumper (you can't have a stock IC).

The other 45degree angle points in to the air box in the engine bay.

For this to work you obviously have to get the dremel out and cut away at the airbox.

Once done it fits really neat and tidy and is so so hard to be seen if you paint the pvc black as the pipe actually points in to the air box. Bit of black tidy silicon around the edge and it looks like factory. :)

20kw is a lot.. :D

If anything it will simply improve the consistancy of performance on hot days and in traffic.

Thats an interesting way of doing it.. :)

 

I went the more bodgy way.

 

I cut a 100mm dia hole under the air box as close as I could before the wheel arch angle occurs.

 

I then used 2 x 45degree 100mm Dia PVC Corner Pipes.

 

One of the 45degree angles points to the front of the car in the inner of the front bumper (you can't have a stock IC).

 

The other 45degree angle points in to the air box in the engine bay.

 

For this to work you obviously have to get the dremel out and cut away at the airbox.

 

Once done it fits really neat and tidy and is so so hard to be seen if you paint the pvc black as the pipe actually points in to the air box. Bit of black tidy silicon around the edge and it looks like factory. ;)

 

20kw is a lot.. :)

If anything it will simply improve the consistancy of performance on hot days and in traffic.

Hi -Joel-, Yes would be nice to set up how you did but requires a fmic and thats not what I want.. I mentioned PVC gutter pipe in my original post, but sounds like I was right, would take a fair bit of work to mount properly. Also, with my setup, there is less risk, because you can return it all back to factory at any time..

I've actually bought myself a bigger side mount so need to keep the piping and stuff in the same location.

But, if I had less respect for my car I'd go the whole way like you.

Eug, yes would be better to take the headlight off, and would definitely do so when at drags or track.

Its not so much about respect its about how easy it is to replace the dogleg should I get defected. :(

To get it installed all up it took me around 2hrs of fiddling on a Saturday.

Anything is easy and very neat if you have the right tools though.

I have a fmic that still uses the origional piping route.

  • 3 months later...

Feedback 4 U - I will be trying this on my NA. Will let you know.

PS - IM very lazy so dont hold you breath for my "letting you know" could be days, weeks, months!!, most likely when i start to sort out the front end of my car (in a couple of weeks prolly)

  • 2 weeks later...
  • 1 month later...
Is the CAI defectable?

Hey dude, yes I guess it probably will be. It must be said I didnt research the legalities before embarking on the change.

It would take me about 5 secs to return this to 'stock' I would just remove the hoses. This leaves no extras, just one missing part that would be extremely hard to notice unless the cop/blue slip provider/inspection station had a really good knowledge of R32 intake systems (unlikely).

I guess the beauty of this is its black and therefore very hard to see unless you are looking. I have been through an RBT the guy looked over my whole car for defects, didnt notice it..

  • 2 years later...
  • 3 months later...
  • 2 weeks later...
  • 3 months later...

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