well in my opinion yes and apsolutely no

whould love to hear your opinions

when cars had carbureters it didnt realy mater what kind of filter they had on em performance filters might have even made a small diference in power but maily they just made the engine sound beter

but these days with fuel injection controled by hot wire and hot film air flow meters puting oil soak filters on is a disasterous idea as oil dosnt stop water and water destroys these air flow meters over time

they only time i can see them making a diference is sumer when there isn't and rain or for track use with highly tuned engines reqireing more air

the original factory fit filters do trap water howether

also how many cars do you see with just a performance filter on and nothing else in the believe that it will help the engine breathe beter dont the plonkers realise car manufactures may have taken into acount how much air the engine needs

earlier i was looking on ebay at a few nonence ideas for geting more horses
and came up with this conclusion

air temp resister+20hp
cone filter+5hp
lambda sensor chip+another 20 hp
fiting all of this+45hp
uno 45 should now have 90hp
actualy believing all of this crap does anything other than **** your car priceless

water getting in is rare, the K&N on a lot of engines will take power away, but a properly though out inductionkit will add a few bhp and torque

This is an old chesnut on the MG forum. K&NS do flow more than a paper filter and still get as much grit out of the air. On a carb engine you must re-jet to get the gain, but a modern FI will re-calibrate itself for the difference (which is not huge. )And Dave is 100% right , most volume production intake setups can be improved.

i agree with you there dave properly fit induction kits do get cooler air than factory fit if done right hence some performance increase

but if it is a realy wet day with lots of spray you cant denie a litle bit of water is going to get in and thats all it takes
i have seen it o so many times
i whould say most of the hot wire and hot film flow meters i have changed have had a performance filters fitted some profecional fit and most just bunged onto the sensor its self so there must be some truth in it

with the paper element filter absolutely no water can get in.


less you drive throu a flood lol

also if that one bit of water that gets throu hits the sensor it will muck up fueling

the hot wire is kept at 400 oC via changes in curent the more air that hits the wire the more curent reqired to keep 400 oC ther buy mesuring the air acurately
so you can imagine what happens to fueling when water hits the wire instead

i must admit i was realy worrid about water with my set up, see pics in my gallery, its got a massive scoop right at the front of the car, but ive been out in some very bad rain and its been ok so far, not sure if the guys with the exposed filters are more at risk or less

Modern engines have, and ive found it on umpteen standard set ups, poor filtering due to a resonance box being used to quieten the engine down. It produces lousy power especially at higher revs when an engine needs more air/fuel. Sticking a performance filter on takes away the resonance box and gives the air a more direct route, helping the engine to breath better. Air does not like going round bends. The K&N on my Coupe Turbo has made a big difference. The rev needle will wind round a lot easier then before, and its easy to hit the rev limiter now. And the best bit, its better on fuel !!
So the answer is yes they DO work.

Andy.

i cant see how a resonance box restricts flow as they tend to be much biger than the final throtle body itself

one of my friends with a scoda fabia vrs 130 diesel you know the ones on 18000 servising was finking about changeing his air filter so i told him first change it for a new standard one and see what happens

turns out scoda servicing is a bit too long it was just blocked up

i begin to wonder if alot of people who fit halfords specials and feel the diference just didnt change there filters often enougth in the first place

i'll tell you what is a wory with bodge it yourself air filters

most people who tend to put it on the throtle body itself have just removed the hot air feed from the exhaust manifold

big mistake in the winter any water that does make its way in tends to freeze onto the venturi in the throtle body tends to be more of a problem on fings with carbs as the fuel in there ads to the afect

can have the throtle iced open and that cant be good

littlepip17 said:

i cant see how a resonance box restricts flow as they tend to be much biger than the final throtle body itself

one of my friends with a scoda fabia vrs 130 diesel you know the ones on 18000 servising was finking about changeing his air filter so i told him first change it for a new standard one and see what happens

turns out scoda servicing is a bit too long it was just blocked up

i begin to wonder if alot of people who fit halfords specials and feel the diference just didnt change there filters often enougth in the first place

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Why do you think its called a resonance box? Because it is there to slow down the air velocity and quieten things down. It allows the air to expand and slow down. The engine is sucking in air and when you slow the velocity down, you are robbing the engine of air and so power and torque. Another thing that bu**ers up the intake charge is the EGR valve. Most malfunction after a while and pour exhaust gasses into the engine, which messes the idle and slow running, causing stuttering and stalling.
Some throttle bodies are so small, that they are strangling the engine [fire engine for example]. Good for economy, not so good for power.
As for water getting in, a small amount of water will do no harm. Infact in motorsport, water mixed with ethanol/methanol, is sprayed directly into the intake to increase air density and so increase both power and torque. this is especially useful to turbo applications. Have you noticed when it is raining or the air is heavy with moisture, that your car feels more powerful? Because the air is denser.

Andy.

littlepip17 said:

but if it is a realy wet day with lots of spray you cant denie a litle bit of water is going to get in and thats all it takes

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how can water get on the filter, or even near it? unless you stick it somewhere silly it will never come in contact with any water. and even if it does as long as the filter is below the intake pipe then water will not be able to travel up the intake.

any airfilter/induction kit will reduce the intake restrictions compared to the stock airbox and paper element filter, and this will give small gains. the powerloss from a K&N (or indeed any filter that is not self contained) is due to the hot air in the engine bay which contains less oxygen (is less desne). nothing else. if you isolate the filter (bmc cda for example) then you do not have that problem, and even better if you can use a cold air feed pipe you will be able to increase the air pressure inside the filter and intake when moving at speed further reducing intake restrictions and giving a tiny bit more gain. its really that simple. but the gains or losses are very small either way and not noticable, its all about the noise really.

in theory a correctly oiled filter will not pass oil vapours into the intake so the hot film sensor will not be affected, although in reality a small amount of vapour will enter the intake when a filter is first oiled, but only for a short while. this can very rarely burn the element out on a hot film sensor. but that is due to over oiling the filter, it only needs a tiny squirt to help it collect tiny particles in the air. it is not a problem with the filter, it is user error.

jug said:

how can water get on the filter, or even near it? unless you stick it somewhere silly it will never come in contact with any water. and even if it does as long as the filter is below the intake pipe then water will not be able to travel up the intake.



in theory a correctly oiled filter will not pass oil vapours into the intake so the hot film sensor will not be affected, although in reality a small amount of vapour will enter the intake when a filter is first oiled, but only for a short while. this can very rarely burn the element out on a hot film sensor. but that is due to over oiling the filter, it only needs a tiny squirt to help it collect tiny particles in the air. it is not a problem with the filter, it is user error.

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Best bit is they are re-useable after cleaning them with some detergent !!

Andy.

just out of intrest today i took my air filter out of my uno and it made sod all diference just alot louder so i supose induction kits whould be pointless on a F.I.R.E ENGINE

littlepip17 said:

just out of intrest today i took my air filter out of my uno and it made sod all diference just alot louder so i supose induction kits whould be pointless on a F.I.R.E ENGINE

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gsr iducuction rr figures for 1108 f.i.r.e
gsr F21i: Typical peak torque increase 10Nm, typical peak power increase 3bhp. Power increase compared to standard induction through rev range between 0 and 4bhp.

I would not recommend removal of the air filter but I imagine you did it as a short term experiment. Usually a power gain of less than 6 or 7 HP is not noticed by the driver, however if you then put the car back to how it was they will complain that the engine has gone "flat".
Carb icing is not connected with water sloshing around, it is formed from water vapour in the air as the fuel evapourtating takes it's latent heat from the surroundings. Its hard to diagnose as once the car stops heat soak melts th ice.

Renegade_8 said:

Usually a power gain of less than 6 or 7 HP is not noticed by the driver, however if you then put the car back to how it was they will complain that the engine has gone "flat".

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by flat they mean quiet, as you say the gain or loss of a few bhp is not noticable, but the loss of induction noise fools you into thinking it has lost power. thats also why you think you get a gain when you fit an induction kit. similarly its the main method used by ecotek to suggest to users that something is happening when you fit an ecotek valve, you hear the noise on lift off and assume it must be doing something (even tho its proven beyond doubt bleeding air into the inlet on lift off does nothing to fuel injected cars). at least induction kits actually make a difference, even if it is a small one.

jug said:

by flat they mean quiet, .

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By flat, they mean the engine has lost its edge in the ability to rev. It is no longer eager to move the rev needle round. You got this feeling from a carb engine when the timing was retarded or the engine ran lean.

Andy.

yea i took it out only for 30 miles down the m6

also it was a cold day right after some rain so there was no dust in the air
just clean cool air

it is a journey i regularly take so i whould have noticed any diference

howether the extra noise certainly does make you fink the car is preforming conciderably beter than before untill you time your 0 to 60 and get a big disapointment

incidently mine is 999 not 1108 who ever that was