I bought a cone filter because a friend told me that it would make a big differance to my scooby ( now i know differant} it has made a big differance but only to my fuel economy im only getting abot 18 miles to the gallon ,am i right in saying thats its the filter? It makes a nice whoosing noise but thats about it. Some mate

 

All they do is suck in hot air and make a nice deep sound, infact they will prob make your car slower thn the stock airbox.
If i were you, id ditch the cone filter and get a pannel filter instead, which tbh wont make much diffrence, but is the wiser choice. IMO

 

The OE airbox on a Classic is probably your best bet at least to 350 bhp. I tried four panel filters and the OE performed as good as any of the other three but I settled on a K+N for its good filtration and the fact it is reusable and cost approximately the same as the OE Subaru so after it has been cleaned and used twice I am in profit.
For your interest the difference between the best and worst of these filters in terms of power was 2 bhp and the filtration of the "best" filter for power was also the poorest so not really a good choice.

The OE panel filter system on New Age cars is an improvement on the Classics and probably good for 400 bhp.

This business about cone filters adding power is another one of these scooby myths perpetuated on this board and others by people just repeating what they have read without any first hand experience and without actually carrying out proper testing to gain true knowledge. It is very unfortunate there is so much misinformation.

 

Uhh Oh! This sounds familiar. I did the same on my old Turbo 2000 when I owned it. It wasn't a blitz cone was it?
I did the same, found that I was getting bad fuel consumption. And also noticed that standing still at the lights, the Rev counter was fluctuating. Took it to the local Subaru Dealer, and they confirmed that the car was over fueling due to lack of cold air. Also I ended up buying a new MAF sensor, as this was killed off by the blitz. Luckily I got the stock filter put back on in time before the engine went bang.