the inferior WRX turbo system

[scottzg]

Making the exhaust gases clean on a warm engine is relatively easy, but cold-start emissions are another story. The main problem is the catalytic converter needs to reach its light-off temperature before it will start cleaning the exhaust.....

....Subaru's solution, as usual, is less conventional. Subaru's flat four layout makes catalyst light-off inherently difficult, since the two cylinder heads are over a foot apart. There is a lot of pipe and a turbo between the first bit of exhaust heat and the catalyst. Subaru's solution was to put a catalytic converter before the turbo! Anyone familiar with turbochargers will wince at the thought, since the catalyst is now stealing exhaust energy that should be making the car faster, but Subaru's solution seems inevitable. It may be unconventional and it may be less-than-ideal, but at least we still have a turbo.


And there you go.

Obtained from http://www.sportcompactcarweb.com/edito ... hnobabble/

[vrg3]

Right... this is why WRX owners like our up-pipes, since ours are catless. :)