This sounds like a lot of work for a little gain, but kudos if any of you guys actually go through with it. I drove around a few days with the rear carpet (which conceals the air filters) removed because I started to do a filter change and ran out of time, and that was very easy and added a lot of induction noise (not very attractive, though).

 

yep indeed it is What I can now tell you is that its a myth (on a Boxster GTS at least & very sure for Cayman too) that the Sound Symposer feeds the speaker grill behind the passenger seat, it simply runs into a dead end in the carpet

 

& even if you fully remove the rear carpet panel, put the hood up and go for a blast, it's not a lot different, you get some belt whirring noises and a little bit of intake sound, but on a GTS at least, all the noise incl afterrun machine gun fire comes from the rear exhaust not the engine

 

Knowing what I know now, its the 3.2 litre GTS engine and the exhaust system which makes the difference, the sound symposer is a small side show and frankly not worth the bother unless it is amplified electronically, which may be a possibility as behind the the speaker grill is a set up for a base and a tweeter

 

? The S and GTS both have 3.4's, and either can be spec'd with PSE. The S and GTS engines are the same, save a tuning difference I believe. I have read that the S tune only allows the throttle body to open 90% of the way or so.

 

sorry GTS 3.4L

 

The Cayman doesn't have speaker grills behind the seats. Or at least mine doesn't. (admittely I only have Sound System Plus).

No - again - the symposer is not amplified electronically.

 

None has; only the Boxster, due to not having space in the hatch (behind the cubbies). It's a crappy alternative location, but no other choice. Sound completely muffled by the seats. Only a sub would be efficient there. Anyway, no symposer on Boxsters either. Saw a GTS with carpet removed and no such hole; only the speakers.

 

The Boxster GTS does have the Symposer, the speaker covers just click out, you can then remove the carpet wall behind the seats. The point is that the symposer sound simply goes into the carpet back not the speaker

 

I stand corrected; thank you for clearing that up. The picture I saw didn't have the tube, therefore not a GTS. Also read before only the Cayman had it, but hadn't seen evidence before. Furthermore, my brother's BGTS doesn't make nearly the racket my CGTS makes, which was the main reason I believed previous reports. Oh well. But that's what forums like this are for. By the way, my reply to the speakers wasn't related to the symposer at all; just that the Cayman has them further back in the hatch area. In both CGTS and BGTS the symposer is the same, with no visible 'grille'. Some folks even removed the thin foam at the end of the symposer foam hole, to make it louder.

 

Well you shouldnt obviously cut a hole in the carpet but as you note, one can remove much of the foam on the lower rear carpet wall section as I have done

 

Ok so I removed all the foam behind the carpet within the black line, if you go for a drive with no carpet at all, with the hood up or down the symposer sound is strangely worse. I also removed all hard foam insulation under the carpet in the rear trunk, this made no noticeable difference when doing the same test, so I reinstalled it. I then put the cut out foam carpet wall back in behind the seats (it fits perfectly still you would never know) and went for a drive with the hood down and hood up. I am pleased to report its an improvement as I guess the wider air space behind the carpet acts as a sound chamber, I would recommend doing this mod

 

Richard, could you please explain better what you said? By 'hood open or close' what did you mean? If it's the part above the engine, it's called 'engine cover'. What I think you said is you only modified the panel behind the seats, removing most of the foam, leaving the engine cover intact, correct? And did you leave the symposer alone, or plugged it? Thx. I wouldn't want my car any noisier than it already is, which is plenty. I'd definitely like to remove the gimmicky symposer because it comes from 0 to 100 all of a sudden, making it almost sound like it's electronic (speakers), like on BMWs, etc., even though it's not. Engine is already loud enough with the sport exhaust, so the symposer is a little too much for me. But glad you found a way to make your car even better.

 

I did not change the Symposer is anyway, just removed the foam from behind the carpet which makes it LOUDER.... Obviously driving with the 981 boxster hood/roof (Hood in Europe = Roof sorry) up or down also makes a difference to the sounds one hears

 

Its a great mod