Wondered if anyone knows (or suspects) whether my 1993 270 Laser with 502 Mag MPI and factory installed switchable exhaust will pass the 90 dB test at idle? I have stock Merc manifolds, etc. I am guessing it will not, but don't want to find out the hard way....

Do you have the Corsa exhaust tips with the built in muffs if so you should be fine

I am not sure if my tips are Corsa, but they are pretty much straight, single wall thickness stainless. They are angled down slightly, tips are cut at 45 degrees and they have a reversion "flapper". But I don't think they do much muffling, thats why I am concerned (but it sounds great...). I will consider changing tips or adding mufflers if I need to, but don't want to if I don't have to.

If there the angle cut they more than likely don't have mufflers. The stock corsa tips are much larger diameter wise at the transom and than there's a small tapper at the tip. My old 1993 Conquest had the angle cut tips without mufflers. And I know it did not pass. But it sure sounder sweet!!

Here's what the Corsa muffler tips look like http://www.corsaperf.com/mbrochure2.htm

I removed them about 7 years ago on my PQ 270 and added silent choice with angle cut straight tips. Sounds much better when under way and now I can route it in the water when in the channel or around the marina. I found even with the mufflers it was a little hard to talk in the boat and we have a pretty long no wake section in Grand Haven.

The water cops have really been cracking down on noise in Grand Haven but they have never bother me. I just put it in silent mode when ever I see a cop.