Sound Generator Modification
- Thread starter sk93
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Anonymous
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I tried this mod earlier today on my 07 plate 3.0si coupe. I removed the pipe from the firewall then removed the foam inserted inside it (my foam was the grey type). I then refitted the pipe into the bulkhead and i heard it click into place.
I then took it out for a drive and under hard acceleration it made almost no difference IMO. The only change was an increased whining noise a bit like a supercharger. I decided to pop the foam back in
I then took it out for a drive and under hard acceleration it made almost no difference IMO. The only change was an increased whining noise a bit like a supercharger. I decided to pop the foam back in
Does it make that much difference?
When I get my car this Sat I may have a go.
When I test drove the car my gf did remark that the car was quiet and she couldn't tell when we were accelerating.
The exhaust is very quiet. Having said that, I did get the car so that it was also quieter than my other car all round. But then 115dB is an easy target to beat!
When I get my car this Sat I may have a go.
When I test drove the car my gf did remark that the car was quiet and she couldn't tell when we were accelerating.
The exhaust is very quiet. Having said that, I did get the car so that it was also quieter than my other car all round. But then 115dB is an easy target to beat!
Bing said:Promised some photos, so here they are... Sorry it has taken me so long
Note that this is for the N52 engine - so facelift, and mine is a 3.0 which already has the sound generator installed. The M54 sound generator is different ; I do not know if a facelift sound gen will fit into a pre-facelift car. ///Ms do not have a sound generator - arguably the engine itself and the two extra exhausts do that job
All this will do is show you how to find the right bits in the engine to remove the foam. It is NOT necessary to take the whole sound generator assembly out as the initial how-to on this thread indicates, only the ends of the pipe that contains the foam.
This is the sound generator. The large rectangle shows the main body of the part, the second smaller rectangle shows the bit we are interested in, which connects to the firewall bulkhead :
Close up pic from the same angle :
Close up pic from a different angle looking from the front of the car, bulkhead connection circled :
First stage of this mod is to simply pull the bulkhead end away from the firewall. Takes some force but just pulls out. Then twist the tube up towards you and you see this :
The foam will be clearly visible in the hole that is circled. Mine is, of course, not present :evil:
The circled bit is important - it is rigid plastic and must be "clipped" back into the metal hole in the firewall. I use quotation marks because there is no set position, just line it up feeling with your fingers and push till you hear it click in. This is the hole in the firewall :
If you want more noise, you need to take the foam out the other end near the engine - this is stage two of this mod. You need to undo the jubilee clip to the right of my finger below (circled in pic 2 above) - quite a long way - and work the tube off. This takes some effort and can result in skinned knuckles.
Your choice whether you remove it completely, cut it down, or not at all. I have cut about 1/3 of it off and then stuck it back in and that's just fine for me. All foam out made my ears bleed and (to my brain) soundedlike I was murdering the engine at 6-7,000 RPM.
Getting this tube back on can be a bit of a PITA - there is a notch in the end of the tube you need to line up with a corresponding 'bump' on the fitting that is attached to the rest of the sound generator. Takes some wiggling and some force too - more skinned knuckles potentially, but worth it. Sorry, no pics of that as I was short on time - but you'll figure it out :wink:
I thought about re-posting the OP's text and my pics, but I wouldn't do it that way, and I didn't have time to take the whole assembly off. Hopefully that helps anyone else looking at this thread now the original photos are gone.
Bing, thank you for the pics. Helped me do mine quick and easy!
Done this mod today :evil:
For those who haven't done this yet. I managed to pull the rubber grommet out of the bulkhead when I pulled on the pipe as it was attached to the pipe. I spent about 30 mins trying to get the pipe and grommet back in together. This didn't work. I later realised that the pipe separated from the grommet. I could then put the grommet in first and then pop the pipe back in afterwards which was far easier.
For those who haven't done this yet. I managed to pull the rubber grommet out of the bulkhead when I pulled on the pipe as it was attached to the pipe. I spent about 30 mins trying to get the pipe and grommet back in together. This didn't work. I later realised that the pipe separated from the grommet. I could then put the grommet in first and then pop the pipe back in afterwards which was far easier.
Turns out mine already had the mod done. Was a little bored of the noise so drove it with it completely removed. Sounds good but the rattle in the interior is too annoying. So parked it back up at home, cut a 1/3 out of the remaining foam and will see what its like in the morning. Need a CAI I think :?
Excellent post, did this last week though it took me forever trying to get the rubber grommet back in. AS someone suggested you can take the rubber grommet off the tube and put it in first then push the tube back through the firewall.
Ok so the results....
When taking out the big foam (closest) to firewall... WOAH!!! The best way I can describe the sound is the same as a vr6 with a k&n induction kit, those of you who are old enough will know what I mean, its loud! At 10% throttle she sounds normal but as soon as you push the loud pedal even at low revs she sounds so beefy and when you hit 4500rpm plus its near deafening!! Its fun for a short while but was too loud and I missed the smooth sound with the rasp of the straight 6.
So I then replaced the big Foam and took out the small foam, now she sounds 10% louder not 90% louder! A slightly beefier sound but nice and smooth and raspy with it.
Top mod and only takes a few minutes!
Ok so the results....
When taking out the big foam (closest) to firewall... WOAH!!! The best way I can describe the sound is the same as a vr6 with a k&n induction kit, those of you who are old enough will know what I mean, its loud! At 10% throttle she sounds normal but as soon as you push the loud pedal even at low revs she sounds so beefy and when you hit 4500rpm plus its near deafening!! Its fun for a short while but was too loud and I missed the smooth sound with the rasp of the straight 6.
So I then replaced the big Foam and took out the small foam, now she sounds 10% louder not 90% louder! A slightly beefier sound but nice and smooth and raspy with it.
Top mod and only takes a few minutes!
Just wanted to post a thanks guys.
I am new to the forum but OLD to Z4's.
My current Black/Black Z4 Coupe 3.0si (07) had 1 previous owner and 28k miles when I picker her up 2 months ago.
This weekend I completed the steps below and removed BOTH the foam parts from the pipe and WOW it now sounds like it should IMHO. I can see why some people, go half way with 1 of the foam only but having tried with both out I could no bring myself to putting one back
I have used information and assistance from these boards for years so this is a Thanks from a very happy Z4 driver in N.London.
I am now fishing for the key information which will help me choose a performance exhaust for the Z will be a 2 pipe as I have decided to stay as Stock as possible (looks wise) and don't want to cut into the bumper for Quads or replace with M bumper.
I know its being discussed on many posts but I would appreciate an up to date confirmation on whats sounds best but NO Drone! Budget is £800 ish.
I live near Enfield can anyone suggest a proven specialist for this work in my neck of the woods?
Cheers again
Jon
I am new to the forum but OLD to Z4's.
My current Black/Black Z4 Coupe 3.0si (07) had 1 previous owner and 28k miles when I picker her up 2 months ago.
This weekend I completed the steps below and removed BOTH the foam parts from the pipe and WOW it now sounds like it should IMHO. I can see why some people, go half way with 1 of the foam only but having tried with both out I could no bring myself to putting one back
I have used information and assistance from these boards for years so this is a Thanks from a very happy Z4 driver in N.London.
I am now fishing for the key information which will help me choose a performance exhaust for the Z will be a 2 pipe as I have decided to stay as Stock as possible (looks wise) and don't want to cut into the bumper for Quads or replace with M bumper.
I know its being discussed on many posts but I would appreciate an up to date confirmation on whats sounds best but NO Drone! Budget is £800 ish.
I live near Enfield can anyone suggest a proven specialist for this work in my neck of the woods?
Cheers again
Jon
blobslosak
Member
Oh my god. I thought people were exaggerating but seriously, what a difference. I can now fully believe that both foam pieces removed is deafening, just the firewall side one removed is epic as it is
blobslosak
Member
I read something about ears bleeding :? 
Having driven round for the last three years with the foam removed, one piece and then both pieces, I've now put both pieces back in and have to admit that I think this is the best sound for me. I know others prefer the noise, but to me The sound is very on/off whic just sounds too artificial to me. It's also much quieter on the motorway.
Andrew.
Andrew.