Quote:
Originally Posted by Fen335i
Steve Dinan's writeup of his rear exhaust for the M3 mentions that he was going to release a midpipe section that retains the primary cats (near the headers)...but will remove the secondaries and therefore pass most emission tests. I guess he just hasn't gotten around to releasing that product that yet...
here's a cut and paste from his paper:
Dinan will be making a middle racing exhaust system for the M3 similar to the one we manufacture for the
M5 and M6. This racing exhaust will remove the second stage or rear catalyst. Removing the rear catalysts
with a high performance middle exhaust section while still illegal is a lot more practical. First off the middle
exhaust system cost about ½ to 1/3 the cost of a header. The labor is also much less to install the middle
exhaust section. The car will still pass a smog test at the tailpipe and there are no faults set or readiness
issues to deal with when you get a smog test either. This is an Ideal system for a showroom stock race car
T-1 T-2 where the car must pass a smog test at the end of a race and cannot have a check engine light on.
The gain about half of the front cat or 10 hp but there is no hassle and it is a lot less money. On Dinan’s
middle exhaust system we also include 3 different noise level resonators so you can get the sound you are
looking for from your car.
The entire paper can be found here:
http://www.dinancars.com/assets/File...st%20FINAL.pdf |
In that statement, he says they only remove the secondary cats, but obviously, they're all gone.
