156 Airbox - What do others do?

Started by bix, March 06, 2011, 06:00:51 PM

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bix

Hi all,
I recently purchased an aftermarket BMC air filter for my 156 TwinSpark. When removing the old air filter I noticed that there is an internal "trumpet" or cone which connects to the inlet duct and essentially lengthens that inlet tract (see attached photo of the "trumpet"), which ends halfway inside the airbox. Interestingly it doesn't appear in the exploded parts guide (see second attachment). Reading some of the international forums, there is some suggestion that this "trumpet" improves low-end torque but unfortunately acts as a restriction at higher revolutions. I was wondering whether other 156'ers have removed theirs or consciously left it in.

In addition to that, what are the thoughts around removing the snorkel (attached to the side of the airbox - item no.5 on the 2nd attachment) which presumably is there to reduce the amount of debri (& water?) coming into the airbox?

Any downsides on the MAF?

bix

Well, after removing the "trumpet" and installing the BMC airfilter the 2.0TS seems to go a lot harder post 3000 rpms, with no apparent downsides to report thus far. I can't say for certain whether the gain is all to do with the trumpet removal or the new filter unfortunately but looks the the trumpet is going to stay sitting out of the car.