Airbox Smoothing Guide now with pictures

[D.K]

As there's been a lot of talk recently i thought I'd post up a guide I did a while ago on how to smooth the O/E airbox
Hope this is of some help.
Feel free to add anything I have missed

Right you will need
1- pwer drill or dremil
2- grinding stone bit for above tool
3- Sand paper flap wheel for above tool
4- Sharp chistle if youv got one or wire cutters
5- sand paper
6- sharp knife
7- If you want it drilled - 10 mm drill bit
8- 3" flexi feed pipe
9- bit of cloth
10- hot glue gun or mastic
11- very small bit of either 2mm MDF or thick card about 6" x 6"

Be warned this will make a mess

To start remove airbox from car.
When you do the top half place it on the cloth otherwise you will scratch the outside of thr box when your working on it.
Useing the wire cutters snip off all the raised bits of plastic from the inside of the top and the bottom half's of the airbox, DONT remove the funnel that goes to the M.A.F in the top half. Then get the chistle and slice off what you could'nt get to.
Now get the drill with the grinding stone and grind out the bits you could'nt get to with the chistle, this WILL make a lot of mess, if you use the drill to do it all it make even more mess
You can then use the sandpaper flap wheel to smooth the surface down so it is nice and smooth.

In the bottom half where the O/E feed pipe enters you will see a soft plastic oval flap, Cut it off and feed the 3" flexi pipe in. then cut the card of MDF to a shape that will cover the hole left at the side ao the feed pipe and glue or mastic into place.
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If you want a nice induction noise you can drill some holes in the BOTTOM half of the airbox, I drilled the bottom and up the sides, just make sure you dont drill above where the filter will sit, The more holes you drill the more noise you will get I did about 50 x 10mm holes and it sounds very good.
Refit and enjoy

Before and After

Drilled Bottom half of the airbox

Filter fitted

The ducting runs down the left side of the battery and sit's just behind the near side head light

 

[BoomhaueR]

Looks a good guide and I will be following it hopefully sometime this side of xmas.
Could you sort some pictures out though? Especially where NOT to cut, the feed pipe and where you've put the holes in the bottom.

Cheers

 

[Ronin225]

Good guide there mate. I used o-clip pincers instead of a chisel and leaves it very flat so not much dremelling required. Pretty much same tool as carpenters pincers if i remember correctly. Got some 3" ducting of my own that needs fitting.

 

[af1]

is it worth doing this on a diesel, i hear mixed reviews

 

[D.K]

is it worth doing this on a diesel, i hear mixed reviews

Jonjay did this to his diesel amd has had very good gains form it.

 

[D.K]

If it's not too cold at the weekend I'll get some pics up

 

[wisejason]

heres mine after it was done...

 

[paul-murphys]

will this be better then a metal mesh piperross induction kit guys or am i best keeping induction kit? cheers

 

[wisejason]

sticking with a smoothed airbox will be quiet (unless drilled - like DK's I think). Induction kits give more noise but can suffer a little heat soak in hot weater. CAI is the best but cost the most as well - but some would argue that a decent 3" feed to an air box give the best combination of flow and noise (its the route I decided on).

 

[paul-murphys]

what did you put an extra hose to the air box so it has 2 feeds?

 

[wisejason]

no you replace the OEM feed that runs along the wing. you might be able to get an extra feed in but I think it would be a struggle. I'm doing mine over the new year so I don't have a picture, but if you search you'll come across one.

 

[paul-murphys]

where do you buy the replacement feed pipe from? Do you have to move the battery? Cheers

 

[justsean]

can i ask a daft question...there are some obvious benefits to smoothing the airbox, but what are the down sides? (if there are none, why havnt SEAT done it themselves...)

 

[steve_p]

I used a pair of decent sized pliers to remove all of the raised bits of plastic.
Found it easier than wire cutters.
Start at one end of a plastic "fin" grip it with the pliers (end of the pliers touching the surface of the box and twist. Continue along the length of the raised section.
The plastic would break off almost flush with the surface of the box. Only required a minimal amount of sanding afterwards.
I used a dremel with a grinding wheel to remove the slightly raised circular "pads" and any remainng/hard to get to "fins"
Bit of sanding and bobs your uncle

 

[wisejason]

where do you buy the replacement feed pipe from? Do you have to move the battery? Cheers

eBay has loads of induction/rubber/plastic piping and some of the sellers have actual web sites outside of eBay. I think you can just sqash in a 3" intake but there is a guy on the forum that makes new battery brackets for about £15-20 but I can't remeber the forum username.

 

[slim20vt]

saw this thread and my bat phone started ringing Dk or was that your bat phone????? lol

 

[D.K]

can i ask a daft question...there are some obvious benefits to smoothing the airbox, but what are the down sides? (if there are none, why havnt SEAT done it themselves...)

The only down side is, It can be a messie job

 

[D.K]

eBay has loads of induction/rubber/plastic piping and some of the sellers have actual web sites outside of eBay. I think you can just sqash in a 3" intake but there is a guy on the forum that makes new battery brackets for about £15-20 but I can't remeber the forum username.

Halford's sell ally ducting not sure how much though, Also try Demontweek's, if your feeling flush you could use silicon tubeing

You can get a 3" duct down the side of the battery without moveing it.

 

[nibbles]

I had these made but never used them

but instead bought a induction kit

 

[D.K]

Pics added to post No1