Barty said:Abbas said:Barty said:Absolutely bang on! Combined with the Bastuck backbox, it sounds like it should now 8)
What would your recommendation be to make a stock Z4 exhaust sound great? I wouldn't want to spend more than £800ish. Somewhere around £400 would be perfect! I know everyone has a different answer, so would be great to know your thoughts!
It depends on what you want. If you just want a slightly more deep or throaty sound without too much loudness, go for a different backbox such as the Bastuck or Eisenmann. They come up second hand every now and then and require minimal work to fit.
If you want a bit more, leave the backbox as it is and change the mid-section to a non-resonated one. Bastuck make one that requires you to cut the original pipes, or go to an exhaust specialist and have a set made up. Should be able to for £400. This will give you a bit more oomph under load, burbles on the overrun and little to no risk of drone.
If you twisted my arm and I had to pick between the two, then I’d go for the deresonated midsection and leave the backbox as-is. You could then always upgrade the backbox in the future if you felt so inclined.
Finally, gutting the original backbox is a no for me: increased drone kills the fun in my book.
My two penneth! If you’re at Ultimate BMW on April 28th, you’re welcome to have a listen![]()
That's a huge help mate. I may do the mid-section job then, and eventually get an Eisenmann backbox. The no risk of drone kind of sold me as I want as refined a sound as possible while still having a lot of character. I haven't seen a Bastuck one online, is it hard to get hold of one?
I may just be at ultimate BMW! Let's see how we go. Be good to meet a few people off here.








