Cone filter gripes

[Tibbsey23]

Before I start I shall just clarify that my filter is not a cone filter, its cylindrical, but for ease I am going to call it a cone as it is essentially the same thing!



A couple of weeks ago I fitted a cone filter to my 940 as all but one clip was missing on the airbox and the filter was overdue a change. Also having read the article on turbobricks about intake restrictions. I figured that a cone would reduce airbox side restrictions, save sourcing an airbox and give me a reusable filter - so several birds with one stone!

I think the engine responds a little more quickly now, though having never ventured into the world of cone filters, I wasn’t really prepared for the extra noises the cone unleashes - some I really like, some I’m not so keen on. This is my first gripe - the sound of my CBV - Like a dump valve it makes quite a loud noise on gear changes - a bit chav for my tastes

My question here is - does it make so much noise because it is such a compact unit on the mitsi turbo and hence relieves the pressure through a very small diameter route? If this is the case, could it be silenced somewhat by fitting a bigger bore after market recirculating dump valve instead (to protect against the 2.4 causing the engine to run rich if air was simply dumped). Anyone got any experience on this front? would this however affect turbo spool-up as the blast of recalculated air wouldn’t be quite so concentrated?

Secondly - smell. Since fitting the filter I have noticed that upon opening the sunroof especially, the car fills with the smell of my crankcase ventilation system. Presumably this is because having less intake restrictions means that the vapour has an easier route to escape. My only guess is that the smell is travelling from the filter - through the large hole in the inner wing where cold air enters the area - back between the inner and outer wings and through the footwell vent that I thought was non existent on a 940 because of the ECU et al that is in its place. Anyone got any ideas, or any thoughts on how to cure this... should it even be a problem? Is my crankcase breathing heavier than normal? Should I block off this hole and route in an alternative cold air intake?

I know what the easy answer is to all this of course, but just looking at options! Another I have considered is that K&N offer a foam pre-filter, which i guess wouldn’t restrict the intake as much as the original set up and so I would probably still end up on top? Anyone have any experience of these and/or do you think it would help with any of the above issues?!

I know, man up...

[RSF]

Originally Posted by Tibbsey23

Before I start I shall just clarify that my filter is not a cone filter, its cylindrical, but for ease I am going to call it a cone as it is essentially the same thing!



A couple of weeks ago I fitted a cone filter to my 940 as all but one clip was missing on the airbox and the filter was overdue a change. Also having read the article on turbobricks about intake restrictions. I figured that a cone would reduce airbox side restrictions, save sourcing an airbox and give me a reusable filter - so several birds with one stone!

I think the engine responds a little more quickly now, though having never ventured into the world of cone filters, I wasn’t really prepared for the extra noises the cone unleashes - some I really like, some I’m not so keen on. This is my first gripe - the sound of my CBV - Like a dump valve it makes quite a loud noise on gear changes - a bit chav for my tastes

A bit chav?so wouldnt putting the thing on be chav any way?really dont like the way people throw this chav word around as every one is a chav in there own way.

I have found you get more mpg with the standard box and to get good cooling with a K&N type filter it needs to really sit in the bumper where air is hitting it (like the way air hits the radiator).

Also noticed that you can get poor engine idle off these cone filters (cheap or deer ones) but that depends on where it is placed.
You have a shield on yours but still,the cone is in the engine bay and has no tube if you like delivering air straight to is.
The only real gane you are getting is noise,it needs to be some where with air hitting it directly.your sucking in worm engine air there.
Just my view on it as well as my experience,try going back to your original air box and I bet it feels more responsive and you gain around 5mpg and your idling is nice and smooth.Saying that,get a cut out in your bumper and extend it in to your bumper and you will gain a few hp and some quick response.

They all make that sucking swoosh noise,different cars it is louder due to stronger pull of air,t5 for example,more air it sucks and faster,the louder it will be.

Can't see a dump valve making it any quiter either,if any thing it would be louder,even a quite dump valve may be louder then a cone.
Cant under stand the smell issue as the cone pulls in air,not throws it out,may be some thing to do with your turbo,oil leaking on to it and burning.

I am not to good on the turbo part of things,just giving my experience with the K&N on my t5 and a v6 mazda mx3 I have,made the mazda that bad it would just stool all the time,correct placement is key with these induction kits.
ATB

[Chesh740R]

Run your Crankcase breather into a catch can mounted on the firewall.

For one you'll not have crankcase fumes being injested by the engine (which is never ideal) and it should also stop you having the fumes entering the cabin.

As for the noise, the reason you can hear it more is its less restrictive Did you notice that inside the old air box there is a lot of foam padding to quiet down the induction roar.

[davebslater(uk)]

well the CBV is dumping straight back into the inlet tract , ive recently put mine back to std after this mod , and it cures all the noises / stalling since air is being forced out the air filter .

you could get a recirculating type , block the CBV off , mount the recirc close to the throttle plate , that will quieten it down .

as chesh says fit a breather tank in the engine bay with a small filter , and route the escape under teh car, youll have no more smells .

some air filters tho , have a small opening which you can re route the breather pipe back into , looks like you could even drill one into the back plate of that one you have .