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Drilled Airbox



Sib

  Clio 172 (Silver)
Thinking about putting my OE airbox back on the car and getting a decent panel filter for it.

On my VTS I had the airbox drilled and a cold feed running to it and the improvements were great before I fitted the viper.

Comments plz
 
  Carrera 4S. Clio 172. M5
Well that should give you a lot of lumpy cold starts with the winter coming up, and waste a lot of fuel. do you need some agro in your life ?
 
  Vectra :(
Why drill it?

Drilling it will not improve anything, infact the opposite.

The OE design is basically as good as any aftermarket filter. Just bung in a replacement element mate for the difference in price cant go wrong
 
  80MPG BEEZA
i bet people use wood drill bits to drill airbox's so they can do themselves afterwards - planks
 
  Carrera 4S. Clio 172. M5
Lam7r said:
Why drill it?

Drilling it will not improve anything, infact the opposite.

The OE design is basically as good as any aftermarket filter. Just bung in a replacement element mate for the difference in price cant go wrong

HOORAY :clown: common sense is becoming more common....well done Lam7r
 

Sib

  Clio 172 (Silver)
ask a silly question then, get a w@nker to answer. thanks to bri and lam7r for reasonable answers, I'll go with the std.
 
  CTR--VX220D
The 'Airbox' modification is a fantastic mod for the VX220. We actually cut the cold air side away giving a huge hole, and removed the trumpets. This is acceptable in a VX220 because the airbox is in a hole away from the engine so only cold air can get to it. When I RR'd my VX it gave loads more torque on the graph from std... it all cost a massive £0.

However I wouldnt advise doing this on a FWD car due to heat soak implications. No harm in suggesting this though, as it does work on some applications.

HTH's

Chris

:)
 
  80MPG BEEZA
so i'm a w@nker now due to fact of pointing how ridiculous it is drilling holes in an airbox after manufacturers spend so much money making the air filter effiecient then afermarket companies produce products to give the car more air but that obviously couldnt be the best way no some chav decided to put more holes in his airbox so it would get more air in and so the urban legend started....
 

Sib

  Clio 172 (Silver)
no it was the way you did it, making a joke out of a simple question.

Do not mistake me for a young mod mental chav. For the record many cars in the past have benefitted from this if done correctly, just perhaps not the high spec sports cars, hecnce the reason I asked
 
  Vectra :(
I am sure they used to do this to the old porsche race cars so in some applications it would work. As already said the location of the air feed has a lot to do with it. If its in the middle of a hot engine bay then its probably not going to help, however if its in a cold area with a nice supply of air then holes/open cone would work well.

Manufacturers airbox range from good to shockingly bad. The RS box is quite good by all accounts where as on my old 106 gti, removing the airbox assembley and replacing with aftermarket gained 7 bhp
 

Sib

  Clio 172 (Silver)
same with my saxo. drill the side away from the engine and add a large hole with a cold feed pipe and a good panel filter and it was better than std and the pipercross I fitted later.
 
  Clio 172 Mk2
the thing people forget when they contemplate doing stuff to the airbox or replacing it with an induction kit is the car companies spend thousands of pounds designing the airbox for a car and getting it tested and stuff. It isnt a particular shape and design just because they think it looks nice. A lot of planning and research is done on them to get the best out of the car. Induction kits are just one mass produced design which is the same for every model of car with just a different inlet size or connector for the particular car its going on to. I doubt thousands have been spent on every car they do the induction kit for to see whether it makes improvements.
And as for drilling holes in the airbox, if it were to do any good renault would have peppered it with bullet holes to start with
 
  Vectra :(
nosluom said:
the thing people forget when they contemplate doing stuff to the airbox or replacing it with an induction kit is the car companies spend thousands of pounds designing the airbox for a car and getting it tested and stuff. It isnt a particular shape and design just because they think it looks nice. A lot of planning and research is done on them to get the best out of the car. Induction kits are just one mass produced design which is the same for every model of car with just a different inlet size or connector for the particular car its going on to. I doubt thousands have been spent on every car they do the induction kit for to see whether it makes improvements.
And as for drilling holes in the airbox, if it were to do any good renault would have peppered it with bullet holes to start with

Thats not all true mate. Manufacturers work to tolerences and not towards all out performance. If that was the case then why would the renault cup racers have a different designed air feed location and slightly different housing?

Renault need to fall between certain tolerences and emissions etc and so the airbox wont be something you cant improve on. A maxogen for example improves on the OE box its just an expensive improvement for not much gain. However this on another engine etc might see 10bhp just from an air filter.

Peugoet and Citreon make shockingly bad airboxs where after market stuff sees a proven big gain for example.
 

Sib

  Clio 172 (Silver)
As Lam7r says. They are ultimately designed to help with fuel economy, silencing and passing the various EU emmision checks.

The design money is will spent and they do a stirling job, but some people want noise and some people want more power/lower fuel economy. We have forgotten nothing.
 
  Carrera 4S. Clio 172. M5
Sib,

You have asked a perfectly legit question, and you have had some poor answers, sorry about that.

The whole airbox thing is very strange as it brings out the tricky subject of who do you believe...the makers who want your money...the buyers who have given them there money and wont ever admit they could be wrong, and the people who just dont know but have a mate etc.etc.

What is clear however is, changing the air intake messes up the engine management ECU settings. If you just look at shape of the airbox on any car, it took someone a long time to make it work as it should in the space available, and working closely with the electronics designer.
So how can anyone come up with a "kit" that fits 90% of all cars and "improves" performance.

IMHO. These induction kits do nothing but increase the intake noise and waste fuel unless you remap the engine ECU to cope with the changes. A lot of people equate noise to speed.
Have you ever seen and heard a Bentley Arnage take off ? A 2.5 ton car 0-60mph in 5.5 sec. and almost zero noise.

Back to your Clio, Rough running on start up is another possible result of removing the makers airbox, and is caused by the AED (Air enrichment device) which is the equivilent of a choke, (found on carburetor cars or the cold start device on early injection engines), malfunctioning.

There is a small precious metal fillament in the air intake tract that detects flow, temperature and air mass. Combined with readings from the water temp sensor and exhaust probes, the ECU sets the AED . When the engine warms up it will switch it off gradually.

Changing the air intake for a so called performance kit, messes this up big time, as does a dirty air filter, the wrong air filter, a leaking air filter box, a blocked air intake, loose clips on the air intake pipes (drilling the airbox) or a combination of all of the above.

If the rough running clears within a few mins and is not severe then some learn to live with it, it can even vary dependant on the outside temp and levels of moisture in the air when you start up.
Another nasty side effect is particles of dust and even grit or stones are able to get into the induction manifold and while it is not something you may become immediately aware of, cause damage or wear to the engine.
Have you never found stone chippings in your airbox and wondered how they got there.

Be careful taking advice from others on this subject, although well intentioned, these people wont put their hands in their pockets if they are wrong, and you blow your motor.

If I went to look at a car for sale and opened the bonnet and saw a cone filter, I would walk.

This whole thing was done 40 years ago with a device called a Peco exhaust extractor which was claimed to give any car a boost in performance and 10% saving in fuel consumption. The streets were full of Morris minors and Ford Anglias wearing them, we must have saved thousands of gallons of 2star at 2/6 a gallon (12.5p)
NOT !!!

Have you ever heard the story about the Kings new clothes ?
 
  80MPG BEEZA
get a eco power boost valve bet their just as good as holes in the old airbox........ :)

buy a big exhaust if your after the noise namely the cheaper they are the louder they are you can even put holes in the exhaust that will make it sound louder "more holes in the exhaust make the air exit quicker making more power" yes....
 
  CTR--VX220D
I have RR results to proove it works on a VX220.

Like I said I would not attempt it on a FWD car.

I have a BMC carbon fibre airbox on my 172.
 

Sib

  Clio 172 (Silver)
Cheers brian, sounds like some sound reasoning.

I was returning to the oe airbox anyway and will not get my wood drill bits out. What are your feelings on free flow aftermarket panel filters?

Batman, I have a big noisy exhaust and an eco valve (not fitted) that used to be on my saxo but you knew that anyway.
 
  80MPG BEEZA
panel filter is the way unless you have money to blow on a viper/cda i got a viper and tbh meh if i care if it gives any/little difference i had no airfilter at all and needed one if you have the original airbox go for panel filter :)
 

Sib

  Clio 172 (Silver)
gonna scoure ebay for a panel filter and wedge the box back in. Is it worth routing a cold air feed in place of the std one??? or just leave it
 
  80MPG BEEZA
polarbert said:
lol @ drilling an airbox

we've got past this mark now!

if you can feed more cold air into the air box it will help hence alot of induction kit have cold air feeds just make sure its as as far away from the engine as it can to reduce warming the air as it passes through the airbox
 
  Clio 172 ph2
I have a modded airbox on my ph1 (round type). Didnt realise until a few weeks after i brought it. Basically the plastic feed on the airbox with the rivets holding it has been removed to leave a very big hole. The airbox is no longer in the normal position, it has been rotated so that the air feeds face directly at the air intake vent below the headlight and the battery has been repositioned sideways.

IMO in very hot weather, low down power has a slight loss but as the speed and revs increases and it more than makes up for it. Also you get a almighty induction roar when you fully open the throttle.

Also the standard air feeds have been removed.
 
  RB 182 & Lotus Evora
Ok a little confused by one comment...actually a few but ill direct it to this one line:


"What is clear however is, changing the air intake messes up the engine management ECU settings"

How does it mess up the ECU settings? The car's ECU has the ability to adapt and learn new readings within specified limits all the time. It will adapt, if it didnt then when someone does go ahead and puts on an aftermarket filter of sorts then they would have all sorts of problems.

The air box design is not primarly for performance. It does the job with minimal fuss, and most importantly minimal noise. NOISE being the main factor here.

I dont personally see the need to improve on renaults design of the original airbox in the FF2. It has two air feeds as it is, granted one could be positioned better. With a new panel filter - non paper based, i think you will get the most out of the car without the need for mapping it.

All im saying is that the ECU can adapt and DOES adapt depending conditions. Its only when people want to fine tune these readings that the ECU needs to be played with.
 


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