Aha, I thought so! With the windows closed, it sounded to me like piped in sound, thanks for the verification!

 

Another thread brought this one back to mind.

Has anyone else actually disabled the symposer in this way, or any other? If so, what are your impressions?

 

I want more supercharger whine. Maybe I need to modify the symposer?

 

I suppose you could bypass it and pump the unswitched, unconditioned intake manifold noise to the cabin. It's not something I would do, but we all have our own flavors of foolishness, don't we?

You might get more SC noise with the symposer disabled because it will have less channeled low to midrange noise drowning it out. It really only takes a couple of minutes to disable, and it's completely reversible. What have you got to lose? You might actually like it!

 

The biggest and easiest way to get more SC noise is to take the engine cover off. Driving hard also helps.

 

Helps a bit, but not nearly enough. My Mini on the other hand, just SCREAMS. It actually has an actuated flapper on the airbox that opens over 4000 rpm.

 

Good point, less symposer might let me hear more supercharger. Absolutely, some less hazardous sounding variation the first idea is worth looking into also.

 

Can anyone confirm if there's a physical opening to the cabin at the end of the pipe? In other cars with symposer type systems, I've found that it just shoots sound against a part of the firewall, while still being sealed. If this is the same, then it opens up more interesting options. I can use a fogger if necessary to determine this for sure.

 

In the diagram I've seen (https://www.jaguarforums.com/forum/x...5/#post1401294) it appears to be closed. Anything other than that violates the notion of "firewall" and risks letting potentially noxious fumes into the cabin.

My disable method blocks the tube and I have checked the condition of the plug after a short span and also after thousands of miles. There is no indication of flow or blocked flow. There is every indication it sounds better

 

Hmm, to my surprise, it sounds like it passes through the firewall... I suspected this because there is an o-ring seal plus clamps on the associated 'plumbing'. That's a lot of effort to seal something.

 

I've just done the "symposer defeat", 5 minute job, will report back later (probably tomorrow) on any noise difference once I've been for a decent spin.

 

OK, done about 100 km since under various conditions and speeds, with plenty of WOT action, and I can't hear any change at all. Definitely no detected increase in SC whine.
But that could be due to the fact that my hearing is pretty crap, typical age-related loss of hearing of higher pitched tones such as (probably) SC whine.

 

My hearing is pretty badly damaged, but if you can't hear any difference at all, either your hearing is worse than mine, your symposer was never working, or you didn't really get it disabled.

 

All this talk about SC whine, but for what it's worthmy SVR has zero audible SC whine, and it doesn't even have an engine cover. No different when it was stock, tuned, or now with VAP catted downpipes as well.

Nothing compared to my AMGs from 10 years ago, be it stock or modified.

 

I definitely noticed mine was quieter with the 5-minute-defeat but I didn't hear any more from the SC.

 

I never noticed more SC whine but it sounds *better* in that front noises come from the front, back noises come from the back. Also, I can hear the exhaust properly.

The only time I hear the SC more is when I open the window and in 1st gear cruise at about 3000rpm. I still have my engine cover in place, but without the foam underneath.

EDIT: It wasn't the lack of SC whine that prompted me to do this initially. It was the wrongness of the piped in sound.

 

Has anyone tried plugging the vacuum control line?

 

I think I looked at that but went the other way. Can't remember why though. Maybe some T's in the system? Not really sure at this point. Maybe I'll look again tomorrow, but it's not high on my rather full list.

 

I thought I read on another thread that you could simply pull a "symposer fuse"..no? I can't seem to find it now.

 

Found a video of f-type convertible on assembly line. You can clearly see what looks like a “speaker”on the bulkhead. This matches the diagram posted earlier.


Kev

i’ll See if I can find the video link again.