Hey gents!
A Z4M owner here from deep dark South Africa
So I have been doing a lot of research over the past 6 months on a different exhaust for my Z4M - specifically the mufflers. I was looking for someting that gave the car a much more aggresive sound track - the standard boxes are a little too tame for my taste.
So after many many many forums, internet sites, youtube videos I narrowed the list down to the following:
Supersprint
RPI
Rogue Engineering El Diablo
After a bit more thought I scratched off the RPI's - given my car is a daily I think the noise and drone would have become too much. The SS option in SA is priced way too high and so I decided on the RE boxes. (Being called Diablo's is a nice little perc too) IMO they are also the best looking pipes for the Z4 - I really like the nice chunky bevelled edge look and look like a top quality product, no corner cutting.
So they arrived this week and I dropped off at SAV Speed for installation with pre and post dyno runs - I wasn't expecting much but wanted to document it anyway as I havent seen it done elsewhere.
So picked it up from Sav yesterday afternoon and wow... car sounds fantastic!
There is now a lot of deep down bass which transitions into a more exotic sounding M scream as the revs climb.
So between 1 - 3k rpm you get some deep Korn style bass guitar sounds, from 3k - 5k the induction form the Gruppe M takes the lead with all kinds of barking and frothing noises, and from 5k - redline you get the exhaust wailing with some induction roar to complement it in the background - really love the new sounds and improved vocal range of the M with these on.
In addition under lift of or as you get the throttle back on you get some nice gurggling and popping noises, sounds very raw and un-synthesized - exactly what I was looking for!!
There is some drone between 2k - 3k but not overly concerned about it. I will drive for around 2k km to give them time to settle in and re-evaluate. If it is still there and bothering me I might dynamat the boot.
An added benefit I wasn't expecting is a jump in power - an extra 6kw according to the dyno at Sav - See attached dyno graph (Note: I'm in JHB which is 1700 metres above sea level and also SAV's dyno is known for being stingy - it's more about the movement between dynos than the actual readings)
