Peoples thoughts on air filters and induction
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Ive been searching across previous posts and google, and I still cant find the info I want, plus alot of its years old.
Im wondering what people have found to be the best combination when creating induction kits, CAI, short intake pipe, long intake pipe, open filters, enclosed filters etc.
Whats best, foam or cotton? K&N, Pipercross or Green?
IUts a pretty fair statement to say that we all know that its best to have as much cold air in the engine bay and that various locations are better than others, though its also a bit nonsense too as your not really given alot of option on where you want to mount these items unless you want to cut holes, shift other items etc, which just aint worth it unless your doing track days or drag runs.
So this is mainly everyday road use criteria.
Theres also the question of the crankcase breather, do we or dont we need it, and what are the benefits or side effects of removing it from the intake tract and venting it?
My own current plan is to run from throttle body, to a 6" long x 3" OD aluminium pipe with a spigot for the crankcase breather welded on, then into the MAF with an enclosed filter mounted straight to the MAF.
What are peoples thoughts on that, would there be benefit having a section of pipe between the MAF and filter to help smooth out turbulance in the flow of air over the MAF?
Heres the current cheap air filter in question, http://cgi.ebay.co.uk/CARBON-FIBRE-UNIVERSAL-CAR-AIR-FILTER-BLACK-3-76MM-/110578004792?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item19bef67338
Id love a K&N but from what I keep reading enclosed is the best option due to the engine compartment temp, then running a cold air feeder pipe upto it, K&N have the Apollo, but I dont care for spending £100 on it when plenty of people are having just as much success with other cheapy filters and kits, lets be honest, you wont gain alot from simply changing the filter, maybe a couple of bhp on the top end and some better response, im doing it mostly for looks and sound, if it takes off 5bhp i dont care as I dont often find myself on a track, and if I did, Id have a 2.5 not a 1.8!
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having a 1.6 its just a nice noise and imo makes no difference to performance really.
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this is the v6 section :) what kit and setup do you have anyway?
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I have a CAI to the bottom of the engine bay and I díd notice difference in performance. The sound is awesome but it picked up a lot better too.
As for which filter, I use a cheap ass one. Makes it easy to replace when dirty and doesnt affect the performance in a negative way.
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Thats good then, didnt think that a cheap vs expensive would really be worth the extra outlay unless you have money to burn, considering the paper elements are cheapo too.
Does the CAI not get damp in cold weather, overnight frosts or rain?
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Nope. Its pointed downwards and theres a splashscreen under it.
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If you are putting it low then there is a chance of sucking up water so you need to filt an attachment to stop hydrolock happening where it sucks up water, the only place I can find that does them is america.
The other thing is you could fit a ram air kit, that means remove a front fog light and use that as the intake for the induction kit, its the only way to get good cold air rushing into the engine to make a huge noticeable difference.
With buying cheap you get what you pay these days, but if you are serious about it you can buy the full kit from america, I now have some of this kit fitted on my car and intend to expand on it, so far I just have the weapon R secret intake but I want to fit the ram air kit and an oil catch tank to stop the hot oil vapours going back into the engine.
I have found all the parts you need to get the best you can get for an MX3
2.5" universal hydrolock preventer valve
http://cgi.ebay.com/ebaymotors/2-5-COLD-AIR-INTAKE-BYPASS-VALVE-FILTER-ALL-NISSAN-_W0QQcmdZViewItemQQfitsZModelQ3aMXQ2d3QQhashZitem3a61c2f73eQQitemZ250748270398QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessoriesDirect Ram air intake kit
http://cgi.ebay.com/ebaymotors/WEAPON-R-DRAGON-INTAKE-RAM-AIR-KIT-II-NEW-838-111-110-_W0QQcmdZViewItemQQhashZitem439d3113baQQitemZ290400048058QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessoriesBudget kit ( not compatible cone for ram air kit )
http://cgi.ebay.com/ebaymotors/Weapon-R-Dragon-Intake-Mazda-93-98-MX3-MX6-626-V6-Only-_W0QQcmdZViewItemQQhashZitem43a069f50dQQitemZ290454107405QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessoriesDealers website
http://www.weapon-r.com/home
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Just found this ram filter kit in the UK
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I am liking that weapon r claw type filter! No way Im paying that for it, be ok until you add shipping and customs!
Anyways, I just had a musing which Ive posted elsewhere and then the idea brought me back here, if you have a CAI the idea is that the air is colder, which makes it denser, so, if its more dense then it has more force when being moved against or forced into something. So if thats right, then the denser air will push more on the MAF sensor, which will tell it that there is more air entering the engine, which kind of nullifies the whole purpose?
Also, if we were to heat the petrol then the surface friction reduces, aswell as becoming more volatile, like any other solvent/spirit/alcohol does. Would that not mean that there would be better fuel atomisation and therefore a cleaner and more efficient burn?
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alot of kit cars inc atom that use cone style filters have a hydro sock to stop water being sucked in, will have a hunt around to find a link
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dont worry about it, i saw them already and dj posted a link, not the route im going down anyway, bought all my kit on ebay about an hour ago, except for the filter, waiting on a reply from a seller
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@2226633c46=Jesta:
Also, if we were to heat the petrol then the surface friction reduces, aswell as becoming more volatile, like any other solvent/spirit/alcohol does. Would that not mean that there would be better fuel atomisation and therefore a cleaner and more efficient burn?
I realise that this is an old dicussion, and might not get read. I have done quite a bit of motorcycle racing, and you want the fuel as cold as possible for all the same reasons as the air. Being so volatile, fuel becomes vapour with heat energy and has the physical properties of a gas - takes up more space/greatly reduced density. In short, hot fuel=less fuel.
Also given that cars only rev to 6 or 7000 rpm, atomisation is not really an issue. It only really becomes a problem with modern "Ford style" direct injection or revs over 16,000.
As for induction, the whole pupose of the air box is to provide a reservoir of high pressure and relatively still air. To bypass the air box, you need to increace the direct air pressure, so some sort of ducted ram air is a good idea. Obvously, the whole arrangement needs to be airtight so as to avoid the running problems caused by confused sensors thinking that you are running rich.
As for making it sound better, you could play a V8 through the stereo. lol
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Lol, you might have been one to appreciate my zx6r then. One thing I still dont get, why is having an air leak bad, when we put on air filters to improve air flow? Surely its much the same thing, admitedly a leak allows unfiltered air, but why does it cause so many problems when essentially an uprated air filter is doing the same?
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Maybe because the air filter is at the start of the air system, I suppose any air leak after the VAF causes the problems, not before, not too sure or how to 'word' it right, but I think I know what I mean LOL
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The difference is air leaking in after the VAF is unmetered, the ECU can't calculate for it. You could have no filter at all and just have the VAF as the first thing and it'd run fine, aside from the dirt.
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thats how I meant to word it!! :wink:
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Feel pretty daft for asking now, as that does make perfect sense. Not used to air meters and injectors yet
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The other big problem with leaks in the induction system is to do with the fact that the down stroke of the piston is what draws the mixture into the combustion chamber, and the amount of air between the valves and the filter has a specific mass. As you may or may not know Boil's laws of fluids, The main principal of hydraulics is that "you CANNOT compress a liquid" and air moves in a manner very similar to a liquid - you suck at one end of a tube and fresh air is drawn in to replace it at the other end. But air is also a spring (compressible). Springs resonate, which is why you have dampers on your suspension. The induction tubes between the filter and the valves has been carefully calculated to contain a mass of air which will resonate, springing the air into the cylinders, particularly at low revs which helps to make the car drivable. Top end power can be increaced at the expense of low end running by reducing the mass of filtered air.
Cracks in your pipe vent to atmospheric air, reducing the mass of the spring, increacing the resonant frequency, spoiling your idle running. This condition contributes significantly to turbo lag aswell.
Sorry if that's a bit dry and scientific, but it really is how it all works.
Bass reflex porting for speakers works on similar princpals. If anyone is interested I will explain.
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Thats a very interesting read thanks for writing it, dont worry about dry or scientific, atleast I have a better understanding of how it works now!
Cheers
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I'm glad not to have bored you. Still being a nube, I get carried away!
