upgrading air filter

[john1412]

hi i have a 406 2.0 HDi 90hp and i was wondering if i can upgrade the air filter to a cone air filter?

and is there much work involved?

also would i gain much or any performance?

thanks

[Pugman406]

Ive heard cone filters are not a good idea on these cars. I replaced mine with a K&N panel filter, it seems alot more responsive now.

[steve_earwig]

I've heard K&N panel filters are not a good idea on these cars

There's a few running cone filters on the coupe club, I'm not sure how hard they are to fit (I suppose it depends which sort you get, they should have some sort of fitting kit but you may have to fabricate brackets). I'm not sure what sort of performance gains (losses?) you'll get but for my mind the only advantage is it'll make it harder to drown...

[FlySpeck]

Really all filter performance is determined by how much air it will flow.

now since the diesel has a constant open intake and alters fuel pressure and injection rate to rev up, a free flowing filter should make a difference in acceleration time, if it flows better than the oem one. unfortunately its hard to tell what the oem filter flow rate was, and whether the new cone or panel filter is better or worse, plus for a diesel to make more power, it needs more air AND more fuel pressure. I think a filter change without a remap would likely show little or no difference unless the oem filter was very restrictive already - and you cant flow any more air than the intake/head combo will allow already.

a poor flowing filter will suffocate the engine and will make acceleration sluggish, where obviously a better one will have the opposite effect (up until max fuelling is reached, and the governor cuts in) but power is down to fuel pressure and injection timing in a derv and little else.

[StevieboyTD]

If you fit a cone, you'll need to fit it inside the existing airbox, else you just drag in the hot air from the engine bay reducing power.

[jasper5]

[quote="FlySpeck"

now since the diesel has a constant open intake and alters fuel pressure and injection rate to rev up, but power is down to fuel pressure and injection timing in a derv and little else.[/quote]

So what does the Mass Airflow Meter (MAF) and the air dozer do?

[FlySpeck]

the maf measures the air mass entering the engine so that the stoichiometric ratio of 14.6:1 air/fuel can be maintained whenever possible to produce a clean burn. Injector pressure is adjusted (along with duty) to match the air mass to the correct A/F ratio.

All diesels have an open inlet tract, unlike petrols, hence they they produce no vacuum and need a vac pump to operate power brakes etc...there is no throttle plate or butterfly in the diesel but it still needs to know what the air mass is.

Never heard of this dozer gadget of which you speak tho....?

[john1412]

ok guys thanks for that information i'm just considering if at the min, not too sure to just replace the exciting panel filter with a K&N one or upgrade to a cone K&N

also if i fitted a K&N cone filter should i remove the top cover on the current air box or leave it open? thanks

[hammerman]

I fitted a K&N panel filter to my 110 when i had it remapped.For the 2 reasons the tuner recomended it,& also i planned on keeping the car for some years.I had it for 3 & a half years now & have recovered the filter & cleaning oil money already.
As for making a difference,i dont know if it does.But it does`nt make anymore noise.I could`nt get hold of a K&N at the time for the 406,but it is the same filter as the Xantia 1.9td so got that one.

[hammerman]

Also,as mentioned,you would really need to shield a cone filter from the hot engine bay,& fit some sort of ducting pipe direct to the filter for cold air.

[john1412]

hi guys I fitted the cone air filter a K&N 57i, and I’m noticing a better acceleration in the car, all I done was take out the original air box and fit in the new cone air filter, I still have to make a heat shield out of some aluminium or something, but after going for a good hard drive in it and the engine bay getting hot I didn't notice any lost in acceleration so maybe I don't even need a heat shield, however making one up for it won't harm at least