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Drilled Air Box

Discussion in 'A3/S3 Forum (8L Chassis)' started by DJ_Troopa, Jan 27, 2010.

  1. Curt
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    Curt Member

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    [Jan 30, 2010]
    Hmmm, think I might attack my air box tomorrow and smooth it.... Cheers guys. I would like some more induction noise, but don't want an open filter on because of heat soak. Was looking at the Ram Air enclosed kits for £100 on fleaBay, but don't know if they're any good or not.
    #41
  2. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Jan 31, 2010]
    why bother? your airbox is already enclosed...it just needs a decent air feed that you wont be able to give it unless you fit an FMIC.....
    #42
  3. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Jan 31, 2010]
    Started to smooth my new airbox out today and it's a fair bit of hard work! Broke my only dremmel cutting tool just as I started to hack the top half of the airbox fins. The bottom bit is half done but I'm trying to do a first class job.

    As I have a spare airbox it means I don't have to rush the job, I'll try and finish the job next weekend and get some pics up.
    #43
  4. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Jan 31, 2010]
    dooood, angle grinder is where its at.....took me less than an hour to grind them out and smooth it off, and its a good job ;)
    #44
  5. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Jan 31, 2010]
    I was sanding for 45 mins by hand and you can't even tell the fins were ever there.

    Did you do the top half of the box too tim?
    #45
  6. S3 HODGE
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    S3 HODGE Brown passenger seat.

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    [Jan 31, 2010]
    Sounds good Westle :)
    #46
  7. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Jan 31, 2010]
    na mate...... i didnt think about that haha...... have you? are they more time consuming you reckon?
    #47
  8. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Jan 31, 2010]
    The top half will take a lot longer than the bottom have due to their being bloody plasic fins everywhere. I just started on the top half when my cutting blade snapped.

    Onece I've sand papered the thing flat I'm going to give it a quick wet and dry too, it'll be sooooo smooooooth :)

    I'll do a vagcom graph for before and after to see if there's any difference at all or if it's just a load of old ********.
    #48
  9. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Jan 31, 2010]
    na that'll be good mate, keep hold of the results then you may be able to do a before and after 4 inch CAI once you've got the FMIC on..... looks like ive got yet another job to do, cant beleive i missed the lid!! just never crossed my mind
    #49
  10. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Jan 31, 2010]
    You can't do a half job mate! Haha
    #50
  11. S3 HODGE
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    S3 HODGE Brown passenger seat.

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    [Jan 31, 2010]
    Tim will be wanting to buy an Airbox lid after getting the angle grinder out :) haha.
    #51
  12. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Feb 1, 2010]
    you have no faith sir ;)
    #52
  13. mike_plymouth
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    mike_plymouth Member

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    [Feb 1, 2010]
    i took mine out the other day and removed all the fins from top and bottom, also there are 2 plastic blades that are in the tubing which links the air box to the maf housing. i used a dremmel with a mini circular sanding attachment and it was pretty straight forward. Since putting it back together i myself have noticed the pulling of my car from stand still is a lot smoother, it used to have a dead spot and since doing this it seems to have been minimised loads. i would deff recommend doing the mod if u have a spare 40 mins.
    #53
  14. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 13, 2010]
    I've spent all day (7 hours) sanding my airbox down. Here's the final finish:

    [​IMG]

    [​IMG]

    I spent so long on the bottom and you cant even see where the fins were any more because I got it super smooth. I got fed up with the top and only partially sanded it down because I was getting bored.

    After dinner i'm going to do a before and after VAGCOM run and I'll let you know if there's any difference in MAF readings and bhp/torque :)
    #54
  15. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 13, 2010]
    Well here's the results:

    Normal airbox:

    BHP = 256
    LBFT torque = 266
    MAF = 191

    Smoothed Airbox:

    BHP = 258
    LBFT torque = 273
    MAF = 191

    Boost was at 22psi and as you can see from the following graph the actual boost with the smoothed airbox holds a lot longer than with the normal airbox.

    [​IMG]

    It was definitely worth the hard work with the following increases:

    2 BHP
    7 Torques
    Smoother and prolonged boost delivery
    I've also got a load of sound like an asmatic old man and I can hear the DV a lot more now.

    If anyone wants to have a crack at it but doesn't want to attack their own airbox my standard airbox is now for sale. PM me if your interested.
    #55
  16. kitpayne
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    kitpayne Member

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    [Feb 13, 2010]
    Good work!!!!

    Was that just smoothing the box or a panel filter aswell?
    #56
  17. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 13, 2010]
    Yeah sorry I was meant to have mentioned that. I have a green cotton filter. Not bad gains from a few hours work. I'd love to borrow one of the £100+ induction kits that companies sell and see what sort of increase I get from that because I dont think it'll be much, if any better.
    #57
  18. kitpayne
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    kitpayne Member

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    [Feb 13, 2010]
    Which green cotton one did you buy. just the one for the S3? How does it mount inside the air box?
    #58
  19. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 13, 2010]
    It's just a panel filter mate, it just goes in place of the standard one, nothing fancy.
    #59
  20. ALPINE
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    ALPINE Yes its diesel, now cry u lost

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    [Feb 13, 2010]
    thats nuts... its true all the little things make a difference. There is alot of people on here would not beleive that would work because if didnt come from "a performance specialist" and would cuss you. My little 1.8t ran a 156.9 on the rollers yesterday after cleaning my inlet manifold out, smoothing off the ridges and poshing it, Polsihed and smoothed TB with a small 1mm bore out front the edge of the TB. (basicly reduced ridge inside the rubber pipe thats clipped onto the TB) full service and a performance panel filter! i think for a 12 year old car thats outstanding!

    I will be taking my air box off tomorrw and attacing it!!
    #60
  21. kitpayne
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    kitpayne Member

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    [Feb 13, 2010]
    Oh right thought it may have been an induction kit inside the air box. seen that done a few times!!
    #61
  22. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 13, 2010]
    That's excellent mate. I used to do all this sort of thing with my old Renault 5 Turbo, smoothing the TB and drilling out the air/fuel jets in the carb then winding up the boost. Its all good fun and there is easy performance gains to be had for nothing except a bit of hard graft.

    No mate that's the beauty of this mod, it wont cost you anything.
    #62
  23. steviet
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    steviet Member

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    [Feb 13, 2010]
    Ive done this to my airbox to,looks like i need a green cotton filter for better gains tho.
    #63
  24. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 13, 2010]
    If I ever set my hands on a standard paper filter I'll re-run my test and see what the differences are.
    #64
  25. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Feb 14, 2010]
    ive just binned a 6 month old one... bugger

    had a look at the lid the other day when i replaced the filter..... whoah man, your too dedicated.... i cant be arsed to do them aswel!! the bottom were ones were far bigger, the lid will be a job if im ever super bored...good to see the results though matey :)
    #65
  26. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 14, 2010]
    I found an easier way to do the top. Instead of using a dremmel I just used a pair of pliers and twisted all the fins off. A lot of them came off so cleanly that they didn't need much sanding at all.
    #66
  27. s3 Hoggy
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    s3 Hoggy Whats going on???

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    [Feb 14, 2010]
    Cool Ill be doing this next weekend

    Cheers Matt
    #67
  28. steviet
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    steviet Member

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    [Feb 14, 2010]
    What about polishing the inside to or something or is that just going a bit to far??..
    #68
  29. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 14, 2010]
    Maybe a bit over kill mate but you will probably see a slight increase again. :)
    #69
  30. S3 HODGE
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    S3 HODGE Brown passenger seat.

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    [Feb 15, 2010]
    O yea Westle, I want my airbox back! lol.

    Looks good.
    #70
  31. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 15, 2010]
    You can have the airbox back if I can have my finger tips back! All that sanding has taken them off.
    #71
  32. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Feb 16, 2010]
    all those years of 'ulay'ing not paying off ;)
    #72
  33. Welly
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    Welly VX220 SC Driver :)

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    [Feb 16, 2010]
    Good work there mate, impressive stuff.....! :icon_thumright:
    #73
  34. Matt82
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    Matt82 Active Member

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    [Feb 16, 2010]
    brilliant thread. good to see people verifying the gains for these mods.

    you want the squared area of the inlet to match or be a shade larger than the outlet of the airbox.

    some testing was carried out on cgti. typically these airboxes have a venturi at the top. this is actually a restriction. remove the venturi and then bell mouth the hole thats left over

    de screen your maf too. ive seen that gain G/S on vagcom
    #74
  35. fran-s3
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    fran-s3 Active Member VCDS Map User

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    [Feb 16, 2010]
    anyone got a spare airbox screw lol? I lost one of mine and Audi keep ordering me the wrong one whenever I order it v annoying!!!!!!
    #75
  36. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 16, 2010]
    When my FMIC goes on I have a 4" pipe ready to fit as an intake :)
    #76
  37. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Feb 16, 2010]
    four inches!!!?? is that gonna be enough????
    #77
  38. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Feb 16, 2010]
    Thats just girth mate, it's a metre long!
    #78
  39. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Feb 16, 2010]
    impressive...... :)
    #79
  40. JS1500
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    JS1500 Howdy

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    [Feb 16, 2010]
    Haha, I was just about to ask the same thing!

    Wanted: Airbox screw!
    #80

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