the stripler said:
Pass as usual, however he did say that he done the emissions test twice before it was ok. He said it was probably down to a minute leak of exhaust gas where the weld is between the o.e system and the stainless system...!!??
Eh , says i.
Wasnt aware of this, so he showed me.
From middle of car back there it is . Stainless system welded on at the back of the cat right through to the back box .. he said its nothing to worry about whoever done it has done it properly.
Ive allways thought this car was a bit raspy (noisy) under load, so this would explain it. I suspected perhaps the backbox had had a delete.
Can any one advise if this indeed is a sporty exhaust addition to car? As id prefer it quieter due to sensitive hearing.
Thanks
As others have correctly mentioned, the stock exhaust system is stainless steel, made by a company called Zeuna Starker.
The system is comprised of 4 sections:
Manifolds
Section 1 (front pipes with no secondary cats but a small silencer)
Section 2 (centre pipes with a small resonator)
Section 3 (backbox/muffler).
There are 5 main ways of modding the sound that Z4 E85/E86 exhaust system produces:
1. Replace/modify the backbox with a free flowing backbox (most popular)
2. Replace the front silencer with straight through pipes whilst leaving the rest of the system stock
3. Replace the centre section and backbox with a wider diameter Y-pipe or X pipe and a free flowing backbox (known as an axle-back system)
4. Replace sections 1, 2 and 3 for a catback exhaust
5. Replace the entire system with a performance exhaust (e.g catless headers, middle resonator and a free flowing backbox).
It sounds like your car has option 2. I’ve never heard this set up in person but have been told by fabricators that it’s an easy way to get more sound out of the system whilst reducing drone. Unlike a backbox mod which unfortunately creates a boomy drone on these, which is then amplified as you are sitting on the rear wheels, making motorway journeys cumbersome.
I ran a Supersprint Y-pipe and Race backbox on my Z4, which was enough for me. At times I would get a horrible pitch around 2,000 rpm in 6th at 55ish mph. But I put up with it by either speeding up or slowing down, dropping the gear also helped. All in it was worth it as the sound that the car produced under full throttle was night and day better than the stock system. Here’s a couple links to the sound: https://youtu.be/kiFqfq698os + https://youtu.be/VACHoMbGaoE
There’s only one person I know who has deleted the front silencer, middle resonator and installed an Eisenmann Race backbox. Here’s a link to the sound:
https://www.instagram.com/p/Bdpkg_Nl82kQ_vptJY4s1AfEgHexUZuWX1_AwI0/?utm_source=ig_share_sheet&igshid=13025p1rozk41
I believe Mr Wilks currently owns this car however the backbox has been returned to stock and thus is now probably the same system as yours.
Sth. Manchester/Cheshire border
Would be interested to hear what you have.
