airbox drilling...

dose anybody know how big the holes should be if i drill my air box….thats if no one has cheep induction for sale thank you  

Just keep it stock - makes sod all difference.

thanks do you no of any mods that i can do 2 improve the sound without it sounding like one of them jukebox on wheels bilt from bits from halfords i have a 4 in 2 one manafold iam told this should change the sound waitin till i can aford the middile and back box anything i can do till then?
  thanks for your help

different back box

whats wrong with the sound it makes at the moment? Please dont tell me u want it to sound like a scally wagon?!

no no no just a bit tappy just want her 2 sound a bit meatyer shes 22yrs old just wanna do sometin 2 the engine thats if i cant get a hard top 4 her :wink:

Rhoar pipe!! sounds awesome!!! very snorty!!!

a rohr pipe is a big metal tube that replaces the plastic tube from the airbox to the inlet manifold that will aid heat soak in your inlet,not to good really.

Fit a K&N or similar panel filter and drill some holes along the wing side and front of lower airbox using a 20mm hole cutter and these will be in the partial airflow from the frontal area of the car(more so if you take of the guidance wing(those bits that kind of funnel air into the radiator)on the passenger side)this will increase slightly the flow of cold air and this combined with the higher flow air fillter will give you a slight increase in power but probably nothing that you will notice but you will get a bit more induction noise so you'll think your going quicker,add a decent make of exhaust like a jetex or piper(or other equivalent)system and you'll get a decent non-raspy exhaust note

Drilling means warm (from the engine bay) air goes in. If you don't drill it and keep it stock, the inlet pipe and the fitting that goes into the front panel means cold air goes in. Therefore drilling does NOTHING for performance.

I'm afraid its another internet myth.

Golf+Mag during extensive testing found that 7 bhp was gained by drilling the air box and fittng a K and N panel filter .

chudd said

Golf+Mag during extensive testing found that 7 bhp was gained by drilling the air box and fittng a K and N panel filter .

Im not typing it all again - read this - http://www.vwgolfmk1.org.uk/modules.php?name=Forums&file=viewtopic&t=46129

also how much did just the KN get them? and Ill put money on me getting more bhp from my set up  :wink:

M7R said

chudd said

Golf+Mag during extensive testing found that 7 bhp was gained by drilling the air box and fittng a K and N panel filter .

Im not typing it all again - read this - http://www.vwgolfmk1.org.uk/modules.php?name=Forums&file=viewtopic&t=46129

also how much did just the KN get them? and Ill put money on me getting more bhp from my set up  :wink:

I'm glad I'm not the only one to have doubts over Golf+/chudd's claims - is it possible to scan the article in? I am suspecting possibly, they did the tests on a rolling road with the bonnet of the car open and the RR's big fan running at a constant speed - not particularly representative of real world driving conditions!

just put a K&N filter in. It does sound slightly throatier but does bugger all for performance.

It just makes me laugh all this 'drill holes' and use 'cotton wool instead of a filter' - 'now mines now goes over a second quicker to 30'….'burnt a ferrari at the lights yesterday….'

1 or 2 BHP will make no difference if you ever see an improvement + your driving a classic why to you want to sound like a boy racer??

lol good point! my rhoar pipe sounds cool    loud enough for me anyway.

Drill the airbox to pieces.

Mine was swiss cheesed with a hole saw on the bottom and right hand side with a pipercross filter and sounded awesome. bugger all difference in power but the sound is worth the 10 minutes work and ?30 filter.

Charlie-Sline said

just put a K&N filter in. It does sound slightly throatier but does bugger all for performance.

It just makes me laugh all this 'drill holes' and use 'cotton wool instead of a filter' - 'now mines now goes over a second quicker to 30'….'burnt a ferrari at the lights yesterday….'

1 or 2 BHP will make no difference if you ever see an improvement + your driving a classic why to you want to sound like a boy racer??

im 32 does liking induction noise mean i also am a boy racer? PaulC your engine bay once travelling is subjected to a throughflow of air,like i said remove the left hand butterfly cover from the radiator(if your crazy mad move the battery for even better cold air feed)and you WILL get more frontal area cold air intake,cold air equals horse power however minimal. The pansyass tiny air intake on the standard airbox is the original chocolate fireguard and any improvement on standard is welcome

drilling the box will NOT give you any noticeable increase in bhp in fact chucking out your rear seats would be a better mod but id still have a drilled box over a power rohr,drilled correctly the airbox will scavenge more air and hence power

rohr pipe:-if you can touch a rohr pipe after a hardish run and its warm to the touch then your raising the intake temperature which will affect your horsepower more than a couple holes

either way youll only be a horsepower or so up or down,both give similar effects and if your not interested in classic status drilling holes is cheaper,better and will have a better gain than a rohr pipe in real world conditions. The proposed gains from a power rohr were supposed to be from the 'smooth air transit into inlet plenum'which ffs just read the quote

drill or rohr its not a turbo conv.so dont go chasing lambos

a mate of mine drilled his air box, sounded awsome, he modded it to let more cold air in (modded grille and a cold air feed?) it added a noticable pick up over standard, still running standard exhaust though and he found the car actually ran too cold, so he had to get another box and put less holes in it, still sounded good but he changed to induction in the end