Bastuck Exhaust Review for Z4 Coupe Si (NON-M)

[3002 tii]

I had an incredibly difficult time finding an exhaust that fits the post-facelift Z4 (non-M) coupe. I first purchaesd the Stebro muffler which required more modification to the stock setup than I preferred but the noise levels eventually got to me. I then found a great deal on a Milltek setup and I've always had great experience with Milltek products for their Audi/VW application. However nobody was able to confirm if their 1 system was meant for pre or post-facelift. I got conflicting info but I figured what the heck... I bought the system only to find out fitment was definitely for pre-facelift, and there was no way to make it fit. Piping diameter, bends, everything were different.

You'll find alot of systems for pre-facelift or the M but not many for the coupe si. Some will advertise as a direct fit but based on my experience above, there is no 1 system fits all. I know that Supersprint offers one but from the one review I found, it was clear that it was for pre-facelift (The muffler hung way too low, hanging below the rear valence and just looked bad imo).

Fast forward few months and I then found 2 systems that were advertised to fit the post-facelift coupe. I know this b/c 1) they either had separate model for both pre or post-facelift or 2) they showed a picture of it installed on the coupe. The 2 choices were Arqray & Bastuck. Arqray unfortunately was muffler only, very expensive, AND too loud. Didn't know anyone else that purchased a Bastuck system but I saw their products on the other 3-series / m-fitments and users reported good experience so I jumped the gun.

Thanks to Julius @ WheelSTO for sending product & confirming fitment and the guys at Quattrohaus (www.quattrohaus.net) for their consistent quality work.

Bastuck offers 2 systems, one for pre and other for post-facelift. They also offer a straight pipe system and one with a silencer. I opted for the latter b/c I wanted performance w/o the drone. As much as I love to rev the car at a light, I didn't want to lose the ride quality from the car.

I forgot to mention they offer 2 style of tips. I opted for the slant cut which follows the lines of the bumper horizontally (whereas the traditional straight cut also offers a staggered setup but the angle is cut vertically - think stock tips, but cut on angle top to bottom. Slant is that plus its cut horizontally as well). I love the tips, they're bigger than stock and sleek. My only complaint however is b/c they're single wall tips, it's sometimes hard to see them from a distance or in the dark.

Fitment - Unlike the Stebro muffler or Supersprint, it was pretty dead on. The only slight modification necessary was the cross-bar by the rear axle. The piping is either too big (or hangs a bit too low) so you can't fully secure the cross-bar so the shop had to put a slight indent (in the bar, in the shape of the exhaust piping) to get it to fit. Didn't bother me, and when I say slight... I mean its nothing that'll alter the structural integrity of the cross-bar. And lastly, the tips are so big they actually almost touch the rear valance. I was concerned the heat might melt some of the plastic but there's a tiny bit of space to prevent that from happening. In the 2 months I've had it, no issues so far. But I think this is really hit or miss depending on the car/exhaust (when you're talking about difference of millimeters).

Sound - Sounds awesome! Since I opted for the system with the resonator, it's not much louder than stock but the tone is vastly different. It's hard to describe but it sounds way sportier and cleaner. It actually sounds more like the G35 exhaust tone... However if you prefer something louder than stock, you're better off getting the system w/o the silencer. I'll post videos soon.

Overall very happy with the system. Fitment was probably 9/10 (tips close to bumper). Sound 9/10 (a tad louder would've been great but no silencer option would address that). Performance yet TBD.

*edited
Slow day in the office so actually stepped out lunch to see if I could get the tips fixed. I figured add a spacer/washer or at most bend the hanger. Turns out it was simple as adding a spacer. So for those who are interested in this, I'd say definitely worth it given the fitment is not an issue.

[Incompatible]

Did you get a chance to weigh the system or can only before the install? Any change in sound after having it on for a while? Lastly, when do you expect to dyno it? Keep us informed. Thanks

[Rick Hunter]

Very nice. But they need to be adjusted down a little.

[GP20]

Originally Posted by Rick Hunter

But they need to be adjusted down a little.

+1.

[Burt Reynolds]

Originally Posted by GP20

+1.

X Eleventy Billion

Otherwise, very nice.

[3002 tii]

went during my lunch break, had them add a spacer on each side, tips now fixed

[ciliz]

so how much did the system cost?

[3002 tii]

i believe msrp was bet 13 and 1400 but being the guinea pig i got a decent discount. you should call julius at wheelsto to see if you can work out pricing. you can look up the product at www.bastuck.de (and just choose english)

[Hawkeye]

Good review Glad to hear there is at least one good performance muffler out for the si!

[3002 tii]

Originally Posted by Hawkeye

Good review Glad to hear there is at least one good performance muffler out for the si!

no problem. it just sucks that only 10% of the z4s produced were coupes, and of that 10%, some are the m-coupe which have plenty of options. glad i was finally able to track down a quality system. its a shame that milltek system didnt fit b/c i'm a huge fan of their exhausts.

[Maroon]

How is the sound compared to the Stebro muffler?

[3002 tii]

stebro sounded nicer on the outside as it was more aggressive but there are no real gains to be had with stebro. and the interior cabin was too loud. a better comparison would be the stebro vs the bastuck no silencer option.

[motorknut]

looking forward to those videos! from your description of the sound, looks like the perfect exos for my Z too.

[zkeeper]

Sorry you had Stebro fitment issues--but it was simply due to the preface model probably being fitted; I also have the 08si [nonM] and in talking with so many here, heard of this issue. Canada was about to send the pre-facer to me, and I reminded them of the differences. They got a post-facer into their shop there who also wanted one, they called and confirmed it was different, went to work, got a fitment for the post face lift, it was sent in 4 weeks or so. It not only fit right up, it took them all of 45 minutes start to finish. Put in better clamps than they sent, it did not hang down, [which I was heavy on re: their jigging it up before sending] and the sound is not harsh. The tips are double walled, and we had plenty of adjustment room for how far in or out the tips would finish out Lovely fit and job done. It was just the back unit, cutting, fitment, adjusting to my likes, and was out in less than hour. As I said, I did have my shop order some better clamps, but Stebro sent all I needed, and at a decent price. The break in has been nice, deep growl, and not harsh drone at cruising. Glad you got a final fitment tho, you will enjoy it because you finally got something to work right for you. I had had Stebbies on many Brit cars and just desired same for the Z4...bests.

[Christurneruk]

Hi all, reading the reviews on the exhaust, and also having trouble finding a setup for the 3.0si.... I'm toying with the idea of having the centre boxes replaced with straight pipes leaving purely the stock back box. Anyone know how this will sound and if I should maybe just remove the larger middle box? Thank you. Ps. I'm new to this. :-D

[liamket]

Bump