induction kit or replacement filter

[steve dynamique]

Whats the best way to go on changing the filter, I mostly use the car around town and on the A roads.



Do i go for an induction kit or will it just choke when in traffic?



Or do i just replace the element in the standard air box and will this make much difference? ie will i get a noticeable change in induction noise, i know i aint gonna get much more power out me 1.2!!!!!



Any views appreciated.

 

[Anders]

If u want noise go for the induction kit, a tiny bit of power go for the replacement element.

 

[BRUN]

do you have an engine bay shot ?

if the air box is placed at the front of the car and fairly away from the engine then get an induction kit as long as you can give it a proper cold air feed, otherwise get a replacement performance element

 

[M.C.]

Get the Cone filter. All trust me when I say it works on this engine. Its very different to all other Clio engines. Ive stripped the entire inlet system down from inner wing to the head, so I know it well. The standard airbox and 1" diameter inlet tract are the most restrictive part of the system. The engine bay has so much room that heat soak wont be an issue. There is no hesitation, or loss of low power, and it revs more freely above 5k. The adaptor plate has also been a handy place for fixing some nitrous kit.



MC

 

[Captain Slarty]

first thing you need to consider is WHAT do you want to achieve ??

if its simply noise, then remove the air feed pipe to the filter box... simple, and free..

the std filter these days flows as well as a k&n etc.. so not worth bothering with them...

 

[M.C.]

Captain,

The diameter of that intake pipe must seriously only be about 1", almost half that of the throttle. There is a large boxy plenum before you reach the throttle. Once removing the standard filter, I can fit my hand and arm into this plenum and touch the throttle. This design is strange, and surely the shape of it will mean that you dont get the hesitation normally caused by fitting a cone filter?



MC

 

[Captain Slarty]

the small diameter is usually to maintain low end torque (A slight venturi effect)

on a small size engine, you mat well gain some top end but usually by the loss of bottom end flexibility.

try just removing the std element completely for a quick trial (you will need to remove and thoroughly clean the airbox assembly though or you will draw crap into the intake manifold..

if you notice an improvement, then consider a filter change.. but as I said, most modern filter elements are superb, nothing like those of 10 -15 years ago.

the effect of fitting a cone filter could be made by removing the present intaske (narrow) pipe, and fitting a larger cold air feed after opening out the hole in the airbox.. (it would work just as well as an induction kit too.) - ie - give more noise, maybe a sllight (very slight) top end improvement and a loss of flexibility...

Most driving is not at full throttle, so you often end up with less overall response and drivability.. again, depends on what you want...

Contrary to popular belief, the induction system goes through loads of development (by the manufacturer) to achieve the best all round results, (Noise, filtering, fuel consumption and response) if you want to change something, then kewl, but be prepared for losses elsewhere.

Induction noise is a funny beast, like exhaust noise (and, Noise dont automatically equal power at all !).. it might sound good for a week or so, but may well get on yer tits after that..

there is an intersting argument that goes like this

car A has an induction kit

Car B doesnt (Same make n model of car)

which is quicker if car A has gained a whole 2-3 bhp at the top of the rev range ??

Answer, probably car B, cos in their haste to quote apparant improvements, most add on suppliers fail to show coresponding losses at other areas...

J.

 

[M.C.]

I see your argument. I have spent many an hour playing with choke sizes and trumpet length to get the best compromise between torque and bhp on Novas. This is why when I think about altering a component, I really do just that, think about it. The first thing I did is try running without any box or filter. And as you say, I expected to get a huge flat spot on full load at low revs as the airflow slowed down, but I didnt experience that. My only thought behingd this is that any air acceleration in the narrow standard intake is lost in the large plenum chamber, where the air must swirl around like mad. Its not like a normal inlet plenum. You normally have a tuned length of trunking of the same or similar diameter leading to the throttle and then seperates into each port. The airbox on that design can often act as a resovoir of air, and the extra restriction does increase airspeed rather than let it flood in killing low down torque. the 1.2 system has the narrow intake in the wing, flowing into what Id call a filter housing, not an airbox, there is no volume to it. That filter sits directly on the plenum on an orifice of about 3x6 or 4x8 inches which opens up further into the LARGE square plenum which is split horizontally in half by a panel in which the throttle sits. Ive tried every combination, and have experienced no hesitation or loss of torque. And thank Christ it isnt that loud either.

 

[Captain Slarty]

excellent !.. well done on sorting out the basics first m8 !.

There is so much one can do with the basic system first to see if improvements can be made.

J.