21 replies to this topic

[turbo boy]

Hi fellow VX owners, The tuning bug is starting to bite. I have seen that Courtenay do an air box mod? Does anybody know what this involves - can it be a DIY job and is it worth it? Would really appreciate to know peoples thoughts. Kind regards, Jon

[Nath]

Do a search on airbox mod, and loads will come up! The idea is really, is to remove the trumpits inside the box, and cs drilled a small hole on top of the box, for more air to flow in! It will sound more throatie, like an induction sound really, Worth doing!!

[VXTyrant]

Don't drill the top of the airbox though… you need to drill the bottom where the air is initially sucked in as you don't want nasties getting in the bit after the filter which leads to the turbo… Pro's are induction sound and ever so slightly improved throttle response, no real cons imo! I've put a video up on YouTube of mine showing various stages of airbox mods - Link:

[Nath]

How come cs drilled the top part of my lid?

[VXTyrant]

How come cs drilled the top part of my lid?

Dunno, unless we are referring to the same side but there is some confusion. It's definitely the part that faces the air intake/turbo ear that needs the holes!

[Nath]

Il take a picture in the morning when i have a clean up Hows the larini system now its all run in? Louder? Have you had a db reading of it recently? Im after a back box, just dont know if il get through or started on any track days with it on lol!

Edited by Nath, 03 October 2011 - 11:42 PM.

[VXTyrant]

Il take a picture in the morning when i have a clean up

Hows the larini system now its all run in?
Louder? Have you had a db reading of it recently?

Im after a back box, just dont know if il get through or started on any track days with it on lol!

It sounds quality, especially on the overrun! It doesn't sound super loud from inside but by all reports it's NOISY from outside Haven't had a db reading since i've had it but I can't imagine it would be too high for most tracks (would probably be if i'd bought the de-cat as opposed to forking out for the sports cat)

[hutchy]

Surely it would be the side opposite the airfilter that gets drilled. Can't drill between the filter and the intake arm or you will be sucking unfiltered air in?

[-Dab-of-Oppo-]

Il take a picture in the morning when i have a clean up

Hows the larini system now its all run in?
Louder? Have you had a db reading of it recently?

Im after a back box, just dont know if il get through or started on any track days with it on lol!

It sounds quality, especially on the overrun! It doesn't sound super loud from inside but by all reports it's NOISY from outside Haven't had a db reading since i've had it but I can't imagine it would be too high for most tracks (would probably be if i'd bought the de-cat as opposed to forking out for the sports cat)

Definetly gets louder once it is coked up a bit. Shouldn't be a problem for trackdays if it's just the back box it's not like on the na vx as the turbo acts as a sound suppressor.

You can here mine in this vid -

http://www.youtube.com/watch?v=eq5gQ6-U1HI&sns=em

[TheRealVXed]

Do a search on airbox mod, and loads will come up!

The idea is really, is to remove the trumpits inside the box, and cs drilled a small hole on top of the box, for more air to flow in!
It will sound more throatie, like an induction sound really,
Worth doing!!

Leave the trumpet in

Increase the amount of filter that can be used by making loads of holes on the bottom side of the airbox. Leave the paper filter in as aftermarket ones just have bigger holes and let more crap through and gives a microscopic difference in power.

I am going to repeat that you should leave the trumpet in. Removing is detrimental

[VXTyrant]

I am going to repeat that you should leave the trumpet in. Removing is detrimental

There are two trumpets in the airbox! To which do you refer?

[Nath]

[/quote] Definetly gets louder once it is coked up a bit. Shouldn't be a problem for trackdays if it's just the back box it's not like on the na vx as the turbo acts as a sound suppressor. You can here mine in this vid - [/quote] that does sound A LOT better than my milltek system. want more noise lol

[Cookies220]

I am going to repeat that you should leave the trumpet in. Removing is detrimental

There are two trumpets in the airbox! To which do you refer?

Leave the top one in (post filter) as it smooths the airflow before going through to the amm.

[VXT Tim]

So I'm putting the top one back in after 4 years of it being out?

[Adam_B]

Cons of doing it on the turbo are the stupid dump valve sneezing noise becomes louder, is it just me that thinks it sounds sh**? Id leave the airbox well alone and get a nice exhaust for impoved sound and performance

[turbo boy]

Thanks a lot people. As always, everyones advice is appreciated. I think I may take the plunge and upgrade the exhaust system when I can justify the expense? Just because the car does sound a bit boring as standard. Thanks again. Jon

[Whiteboy]

Cons of doing it on the turbo are the stupid dump valve sneezing noise becomes louder, is it just me that thinks it sounds sh**?

Id leave the airbox well alone and get a nice exhaust for impoved sound and performance

And people asking "is that a dump valve"?

Steve

[TheRealVXed]

I am going to repeat that you should leave the trumpet in. Removing is detrimental

There are two trumpets in the airbox! To which do you refer?

Leave the top one in (post filter) as it smooths the airflow before going through to the amm.

Also increases the maximum air flow speed as creates linear airflow. "ripping" the air round a 90 degree sharp angle slows it down and creates turbulance.

[Cookies220]

Cons of doing it on the turbo are the stupid dump valve sneezing noise becomes louder, is it just me that thinks it sounds sh**?

Id leave the airbox well alone and get a nice exhaust for impoved sound and performance

And people asking "is that a dump valve"?

Steve

I must admit, I don't have a problem with dump valves or the sound they make as long as they are actually doing something useful. Adding one just for the sound is pointless IMO.

[Nev]

I think we need a few corrections for this thread so others don't get dis-information. 1. Removing restrictions in the airbox (ie the trumpets) and drilling holes in the rear will increase torque throghout the rev range by allowing air to flow with less resistance, particularily at high revs where the air speeds are suprisingly high. The negative side of this is more noise, as the trumpets are calibrated to reduce resonance from the turbo/induction. Bigger power cars will benefit more from this mod than standard cars. 2. The VX220 Turbo does not have a dump valve. It has a bypass valve which recirculates any vented/boosted charge back into the inlet side of the compressor. This is an important distinction, as dumping the air (to atmosphere) would cause the ECU to get rather confused and nasty driving characterstics. As evidence to back this up on my old 'stage 4' engine, when I changed my top hat (another restriction to air flow) and did the airbox mod at the same time, my car gained 25 ft/lb of torque. I have the before and after graphs to prove it. Hope that is succinct and helps someone.

Edited by Nev, 08 October 2011 - 02:09 PM.