Lets say you have a air:fuel ratio of 10 to 1

So ten parts air for every 1 part fuel right? now if you chuck on a better air filter so the car can suck air in more easily.
Its still going to have this same ratio of 10 to 1 wont it?

So how does the extra air that the car sucks in make it go better, because the car is still using the same amount of air per unit of fuel isnt it?

I'm no expert....... but I think the MAF (Mass Air Flow) Sensor *should* be able to detect the increase in air volume. Based on this - the ECU *should* increase the amount of fuel being delivered to keep the ratio as close as possible to perfect.

Having said that - there would appear to be alot of AMC members who have experienced poor throttle response in the lower half of the rev range after fitting higher flowing air filters. The leading theory for explaining this phenomonon is that with a higher flowing air filter fitted - the ECU is unable to compensate (particularly at lower revs) for the extra air, hence the car will run 'lean' and power will be lost.

Some possible remedies that have been discussed over the last 6 months (that I'm aware of) are:
* ditch K&N filter in favour of STD mitsubishi paper filter
* Fit Piggyback ECU and have it tuned
* Fit "Barry's Lean out Kit" (see Sticky topic in this forum)
* Fit Rising Rate Fuel Pressure Regulator
* Fit "Hi Flowed" Throttle body

For more info see Acceleration dead spot 1500-2500 rpm? (http://www.aussiemagna.com/forums/showthread.php?t=12089&highlight=dead+spot) or K&N Air Filter Panel Lean-out (http://www.aussiemagna.com/forums/showthread.php?t=25097&highlight=lean)

that question doesnt realy make sence. in a motor you want 14.7 parts air to 1 part fuel for the best bang, but you can say 14.7 liters of air at 40deg or 14.7 liters at 4deg the cool air is more dence which means a better bang but its still the same ratio hope this helps....

the best way to make any motor go harder is let it breath ....air filter. exhaust..cams...valve size ...turbo....ect all these things let more air in and let it out quckly

in a motor you want 14.7 parts air to 1 part fuel for the best bang
Note quite true. 14.7:1 is the ratio at which combusion will be most 'complete' (i.e. least amount of left-over unburnt fuel), but isn't necessarily (or usually) the ratio for best power.

true but if running lean you burn out valves and rich you burn out cat

Agreed, but show me a car that runs 14.7:1 at WOT in open loop mode from the factory..

no motor does
if they did you wouldt have acceleration

I know.. so why are we arguing? lol :P

Arh, i get it now.

See i thought a 10 to 1 ratio was the same all the time.

But that 10 parts of air could be more compressed and hence have more oxygen to burn then another 10 parts of air, makes sense now.