It's worth a try. A few have tried exhaust cutouts and it's possible you might have a gain. Not sure whether its on this forum or on mbworld but one of those threads are on the necessary back pressure needed for our motors to perform. Hence the need for the cats. Most have gone to high flow cats, but very small gains have been proved. Also the lack of monitoring DA and just dyno's are unpredicatable results that may not translate over to the track in lower et's.