Fitting a K&N to a carburettor BX

[Willy]

Decided I'd chav up and investigate buying one - there's plenty of universal cone filters on ebay for about the £20 mark.

Question 1: since I'd be removing the OEM air box etc, where would the oil breather pipe outlet go?

And 2: Would the extra airflow intake warrant mixture adjustment or would I be only burning insignificantly leaner?

Thanks

[Mickey taker]

why not get a K+N replacement panel filter ? Direct swap without any faffing about.
I thought the cone induction kits were mainly for injected cars

[Tim Leech]

Personally i think it wont make any difference to a carb fed bx and would be a waste of money. The induction noise may make you drive it harder than normal giving the illusion of more speed.

[Mickey taker]

ah but the K+N panel filters last forever so are cheaper in the long term

[MULLEY]

I've got some k&N 33-2539's available for £20 each, which i'll be taking to the ICCR, so if anyone want's one, drop me a pm & i'll reserve them for you

[Mickey taker]

have you found them now then Matthew ?

[MULLEY]

Yup, i'd left them on a shelf from the rest

[Willy]

Not such a fan of K&N panels - mine tend to get blasted with oil anyway so the turnover rate is generally quite high!

Was thinking more along the cone lines - a universal fit horizontally installed to the carb intake similar to Phil's set up (yes I know this is a diesel)

[Kitch]

Panel filters provide very little if any performance increase in my experience. I don't buy into the lifetime filter stuff either....I'd just replace it yearly with a standard one - it'd take quite a long time to get to £35 when you can get air filters that cost £3.50! add it to the fact that many don't use the BX as a daily drive, which means you probably don't have to change the filter as frequently as the oil.

Cone filters do tend to improve performance on MPFI petrol engines, as do bolt on carb-filters. But both are sensitive to under bonnet temperature (very much so in the case of the bolt-on carb filter) so it's just as easy to end up with a negative result as a positive one. At the end of the day they can both shift more air than a standard air box though.

[Mickey taker]

I still want a panel filter but then again my BX is my daily and covers at least 350 miles a week

[MULLEY]

Mickey, you're name is on one anytime matey, i'll be at the ICCR & can meet up there? Or do you evah travel north mate, i'm just off j29, pop in for a cuppa & i'll fit the filter for you

[Mike E (uk)]

The benefits of a K&N filter on a carb car depends on how restrictive the air filter and intake ducting were in the 1st place.
The 205 XS and AX GT have a restrictive system, and the replacement K&N system provides a noticeable power (and noise) increase. I have experienced this on my own 205. The BX with the same engine would obviously benefit equally.

On an EFI car, the mixture is adjusted for you by the air flow meter. I use an K&N panel filter on the BX and 406 and have kept the original boxes and ducting.
It is only a bit noisier than the paper version, and the cold air feed is done for me.

On carb cars you need a larger jet size to correct the mixture. The K&N kit for the 205 comes with the required size jet.