jase128

have read in a few places about the advantage of removing the snorkus(resonator box) from a impreza's air intake,does anyone have any advice on this...good or bad.
also does anyone know if a snorkus delete elbow is available in the u.k? all the ones i've seen advertised have been from the U.S.

scoobiewrx555

Why go to the expense of a manufactured elbow when just chopping the Snorkus 2/3's of the way up does an excellent job.

The idea is to get cool air from the inner wing cavity into the airbox as well as what's coming in from the air scoop at the front. That scoop only works when you're moving anyway so when you're stationary cool air from the inner wing helps keep stationary intake temps down as well as when on the move.

Additionally, there is a rubber strip attached to the front of your bonnet that impedes airflow to the plastic snorkel/scoop. Cut that away to the same width as the scoop intake and that gets rid of another restriction improving airflow through the scoop.

carl heath

never heard of that scoobiewrx555,does it work well when trimed then ? might get cutting,lol

scoobiewrx555

Which bit are you talking about trimming, the rubber bonnet strip?

If so just look as you shut your bonnet, you'll see the rubber strip attached to the bonnet right in front of the air scoop completely blocks it off. The scoop is great in principle but when you see what's in the way you wonder how it gets any air at all.

Anything that may help with airflow is worth a bash and better still it's free!! Same goes for the Snorkus delte modification. On my own car i've logged 2-3 degrees C lower intake temps and 2-3g/s better airflow with the whole snorkus delete and rubber strip mod.

Splitpin

Both Harvey and I have tested this quite extensively (with proper monitoring/logging/attempts to map around the effects) and found that, on balance, removing the resonator to be a slight disadvantage. The resonator, as well as reducing induction noise, also reduces turbulence in the induction tract prior to the airflow meter. Without it mass airflow measurement accuracy/consistency was affected beyond the point that the ECUs error correction strategy could cope with it, and so, ultimately, was power. Can't remember the number Harvey came up with for certain but I recall it being a consistent 6bhp loss. My own tests found that I'd need to offset the mixture slightly richer in order to ensure that the lean spikes caused by the resonator delete didn't cause any problems.

If you want to know more I'm sure searching either of our posting histories will bring up the relevant threads. Personal recommendation however would be that as long as you are running the standard airbox, leaving the resonator in place would be the preferable option as on the basis of personal experience, the engine runs better and more consistently with it in place.

As above if you are going to do this there is little point paying over the odds for a piece of plastic to be sent across the Atlantic. You may as well just cut the existing one up. In the circumstances I'd suggest getting hold of a secondhand one to experiment with, so at least then you have the option of swapping back to standard easily.