GolfGTIforum.co.uk
Model specific boards => Golf mk3 => Topic started by: locin78 on 08 July 2009, 23:30
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I have a standard mk3 gti 16v is it poss to customise the standard air box the car came with for more BHP??
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2 secs of searching brings up this http://forums.vwvortex.com/zerothread?id=3063843 :wink:
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thank's
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I have a standard mk3 gti 16v is it poss to customise the standard air box the car came with for more BHP??
You can modify it, sure.
But how you do it, depends on whether you want it to sound better, or add more power.
Drill holes in it and let the hot air in from the engine bay...and you are more likely to loose power, than make any.
This is common sense and has been proven many times. To some, it sounds good though.
If you want better performance, you need to increase the internal volume so the engine has more air available when you snap the throttle open, make sure the internal air stays coolr, and feed the inlet with as much cold air as you can. Adding a K&N panel filter adds a small bit too.
Take the silly snorkel thing out for a start:
(http://i188.photobucket.com/albums/z72/Ess_Three/Golf%20GTI%2016v%20Anniversary/Standard16vAirboxTop.jpg)
(http://i188.photobucket.com/albums/z72/Ess_Three/Golf%20GTI%2016v%20Anniversary/Modified16vAirboxTopNo2.jpg)
..and smooth off the edge where the air flows from the airbox to the inlet hose, using a Dremmel.
(http://i188.photobucket.com/albums/z72/Ess_Three/Golf%20GTI%2016v%20Anniversary/Standard16vAirboxBottom.jpg)
(http://i188.photobucket.com/albums/z72/Ess_Three/Golf%20GTI%2016v%20Anniversary/Modified16vAirboxBottomNo1.jpg)
Remove all the hot air feed gubbins (hot air feed from the exhaust manifold). You don't need it. You don't live in the Arctic.
Remove it all, remove the nylon lines that go to the TB, and plug them up at the TB.
With the gubbins revoved you need to blank off the hols that would otherwise let hot air in...tape it up, plug it with something...do what you want. Just seal it.
Then work out how to get more cold air in:
Remove and bin the wing fed small inlet duct thingy.
(http://i188.photobucket.com/albums/z72/Ess_Three/Golf%20GTI%2016v%20Anniversary/Modified16vAirboxBottomNo3.jpg)
I ended up with a 3" subwoofer port araldited into my airbox, which site hard up against the back of my Hellas...so lets far more cod air in than the standard wing inlet ever did.
This way, you end up with cold air from the front, and more of it...smoothed to give better flow (not hot air from the engine bay) and if you add a K&N panel filter you will see about 3-4 BHP repeatable on the Dyno.
That's proper power gains (not much...but nothing ever does despite the ludicrous power claims) up at the top of the revs due to better breathing, better throttle response and a bit more noise.
That's how i've best found modifying the airbox to work...after 8 years of trying many different inlets, cone filters, CAIs etc...this one still works the best.
Or you can drill it and let hot air in.
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That is really useful information ess_three and a really good set of instructions. It seems to be a more well thought out approach than turning the standard turn box into Swiss cheese approach. This should get stickied or something!
Pete :smiley:
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You will always get more power with lots of COLD, dense air.
HOT air reduced power...that's proven.
Swiss cheese the airbox and log the values from the IAT sensor (inlet air temp.) and you'll see how hot it can get in the inlet hose...hot air will see the ECU pulling the timing to protect the engine...hence producing less power.
Ideally you want to take cold air from outside, filter it efficiently with little or no restriction, and get it to the TB whilst keeping it as cold as possible...hence the insulating properties of plastic are a good thing! Plastic doesn't insulate too well when there are a load of 25mm holes in it letting damn hot air in!
The airbox is a good design, and certainly good enough for 190-200 BHP where the cams/inlet manifold start to hinder you getting any more...so why ruin a perfectly good design?
Of all the CAIs, different filters, airboxes etc I've tried and dynod, this works the best all round, road and track, all weathers etc.
It's not a huge gain...but it's repeatable and a gain none the less.
Smooth out the TB at the same time and you can get a wee bit more too.
You'll get more noise from a drilled airbox though...
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hey, i think this should be stickied!
its brill!
now i can see what i need to do properly when i get round to it!!
thanks m8!
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Good write up man and thanks for the info.
I wonder though, i have the 1.9 tdi AHU engine, of course being the diesel, my airbox is slightly different.
What do I need to differently with regards to modding my airbox?
thanks
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Good write up man and thanks for the info.
I wonder though, i have the 1.9 tdi AHU engine, of course being the diesel, my airbox is slightly different.
What do I need to differently with regards to modding my airbox?
thanks
Having never seen a diesel airbox...I can't say. But probably not a lot different...
The principle is the same, as much cold air in as possible and as few sharp edges and restrictions from the inside to the TB/inlet manidold as possible.
Can you post up pics of the insides of your TDI airbox?
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I can certainly take pictures, but how do I post them! lol
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apparentley the cold air thing isnt quite the same with diesels but more air always helps
heard this from a diesel expert on ukmkivs
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I've uprated the nozzles, running powerplus Sprint 520's now, fratelli - the real deal! - or at least will be when I get my injectors back on monday :p
I've read (and it of course makes sense) that when uprating the nozzles, among other things it is definately worth increasing cold air to the system to compensate for the added fuel...
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here' the pictures of my air box.... - 1.9TDi AHU
(http://i703.photobucket.com/albums/ww36/mantasrb/Golf%20Suspension/Golf%20Airbox/DSC00871.jpg)
(http://i703.photobucket.com/albums/ww36/mantasrb/Golf%20Suspension/Golf%20Airbox/DSC00872.jpg)
(http://i703.photobucket.com/albums/ww36/mantasrb/Golf%20Suspension/Golf%20Airbox/DSC00873.jpg)
(http://i703.photobucket.com/albums/ww36/mantasrb/Golf%20Suspension/Golf%20Airbox/DSC00874.jpg)
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Doesn't look to be too much wrong with that...
I'd leave the lid alone as there is already a nice smooth duct to get the air out.
For the base, maybe just work out a way of getting more air in. Bigger inlet?
Get rid of the angled inlet with the restriction at the inlet...and get a bigger inlet in there.
That's about all you can do. Seems to be a pretty good design as standard.
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I took everything out of mine and took the standard air feed off. I bought a new 60mm air feed and put one end in the hole and the other end under the left side of the headlight right up close to the grill.
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is it worth cutting the tubes away from the inside so the air goes straight in ie; not channelled
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No, I wouldn't.
Fine it it's a restriction...but that looks to be parallel, with a flared end...which should air airflow out of the airbox.
I'd leave it, personally.
Look at the inlet though...try to get a bigger, coil air feed in there...from as close to the front of the car as you can.
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. :smiley:
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hey, just to bring this thread back to lifa... again. lol
what dremel bit did you use?
i dont have a dremmel but obviously have a drill, is there an equivelant bit i could use to do the job properly?
seriously looking at doing this soon!
also is there a limit on what size in-let hole ya have, i know ess said that he had a 3" speaker port there, any bigger worth it?
and finally im going to feed cold air from the bottom of the front bumper, anything i should be considering before i go in head first?!
cheers!
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I personally wouldn't have a cold air feed from the bottom of the bumper, think of the crap that's going to go into it.
Water, bugs, stones, you name it, it'll end up in your air filter..
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hey, just to bring this thread back to lifa... again. lol
what dremel bit did you use?
i dont have a dremmel but obviously have a drill, is there an equivelant bit i could use to do the job properly?
seriously looking at doing this soon!
also is there a limit on what size in-let hole ya have, i know ess said that he had a 3" speaker port there, any bigger worth it?
and finally im going to feed cold air from the bottom of the front bumper, anything i should be considering before i go in head first?!
cheers!
i jus used an ordinary hand saw and cut away the lower half on the wing side.. worked wonders
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I personally wouldn't have a cold air feed from the bottom of the bumper, think of the crap that's going to go into it.
Water, bugs, stones, you name it, it'll end up in your air filter..
You forgot Driftwood and the odd Seagull and Storm Petrol :grin:
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ok, fair point made, lol
just the only place i coud think of and space in the bumper, not sure if i want it showing or not.
was gonna mesh it up to stop any big crap going through but i suppose your right!!
maybe i'll just feed it from behind the grill then, not sure, need to plan this properly, lol!
need to find some good hosing too, lol.
have you noticed a difference at all shep??
i know theres alot of debate about power gains etx... but i just want a good looking functional job done really, lol.
cheers for the replies though!!
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ok, fair point made, lol
just the only place i coud think of and space in the bumper, not sure if i want it showing or not.
was gonna mesh it up to stop any big crap going through but i suppose your right!!
maybe i'll just feed it from behind the grill then, not sure, need to plan this properly, lol!
need to find some good hosing too, lol.
have you noticed a difference at all shep??
i know theres alot of debate about power gains etx... but i just want a good looking functional job done really, lol.
cheers for the replies though!!
no gain no loss imo but i like the sound so for free im happy..
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thought so, tbh its more a tidy sound and look for it really.
would having it behind the rad be a good idea or better behind a grill slat? but then that will be next to a hot engine..?
thats why it thought sending it down near the bumper would be a good idea... things to consider eh, lol
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I have to agree about the risks of mounting it too low.
I did my old track car like this,
(http://i10.photobucket.com/albums/a102/robstaples/Picture033-2.jpg)
And know the front end design lends itself to it, but perhaps theres room behind the grille?
Still learning with Golfs TBH
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Never had a problem with drilling, but i drill front and wing side.
My current motor doesn't have a drilled box, it doesn't need it.
I need a motor with a drilled/undrilled box now so can test it on vag com :smiley:
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nice look to that beemer rob, i quite like those ones :)
cheers for your replies all,
well last night i was bored, so i got trigger happy with the drill,
ive only done a small amount compared to some, and i have noticed a difference already, a little more power but alot smoother in delivery i think!!
i think i'll take it off again and do more to get a little more noise though!!
cheers all!!