I was thinking of doing the gundo / fister exhaust mod, but didn't want to wake the neighbors. Instead I found this free, easy, and reversible way to increase induction noise. I already had the Helmholtz resonator delete (orange cap mod) , which helps out a lot.

1. Remove rear cover at the back of the parcel shelf where the rear window meets the carpet. On my 99 it just pulled out, no screws
2. Remove large sound deadening foam piece (minus 1 pound, woohoo)
3. Push rear cover back on.

That's it! It really howls now at WOT =) Exhaust sound at part throttle comes in the cabin a bit more too.

I also experimented by drilling some small holes in the snorkel (a la 993 motor sound package airbox), facing the rear of the engine bay. I was hoping that the noise would come out of the intake, through the rear firewall, and into the cabin. It might have helped a little, but I don't think that step is really necessary. Plus you might suck in some hot engine air.

 

Sorry brother, that is just wrong. Exhaust changes to make a car run or sound different/better is different than simply adding noise to your cabin. A Gundo hack won't bother the neighbors but noise in the cabin will get old.

 

I have to agree here, I have the Fisters/Gundo and it's tame under normal conditions. Just adding noise to the cabin will get old fast, besides you'll be the only one to hear it as the sound comming from the exhaust will be the same.

 

That's exactly what I was going for. Since you are only removing the piece next to the firewall, engine and exhaust sound in the cabin is increased without a large increase in road noise. It hasn't gotten old after a few months. You can always put it back in quite easily. I live on a busy street so I'm biased against aftermarket exhausts - they are annoying when I'm trying to sleep.