GLA35 (2021) Custom Exhaust Setup Complete!
 

So as with most of the GLA35 and GLB35 owners I too found the exhaust note on these 35 models utterly neutered. Completely different from their A35 and CLA35 cousins with a much more muted tone and no pops/bangs/crackles. I'm not one for crazy over-the-top pops/bangs/crackles but a vehicle marketed as an AMG model and with a supposed AMG performance exhaust should not sound like a Dyson.

Anyways, it took two visits to my exhaust guy, simply because we were playing around with the different kinds of setups, but it is finally done!

The stock exhaust setup (from the cat back) included a front OEM muffler, a middle OEM resonator, and a massive rear muffler.. oh and the OEM valve motor / control unit to control the exhaust flap between Comfort/Sport and Sport+/Race.
https://cimg6.ibsrv.net/gimg/www.mbw...5901494782.jpg

What we tried out first was to remove just the middle resonator and create a custom axle back with a Y pipe consisting of a small cylindrical sports muffler on the left tail exit, and straight through pipe on the right tail exit. The OEM exhaust valve motor/control unit was also retrofitted to the right tail exit. This axle back system was attached to the existing OEM mid-pipe with a v-band.
https://cimg9.ibsrv.net/gimg/www.mbw...535a8cfdde.jpg

I was initially impressed and surprised that we unlocked some pops and bangs, most likely from the middle resonator delete and the more free flowing axle back, but what I found after driving it for about a month was that it was way too "boomy" especially around 3500rpm in third gear where it would drone quite a bit. Also, the pops and bangs were sometimes really muffled, most likely due to the from OEM muffler still being there.

So I organised for a second trip to get some modifications done to the setup and this ended up as:

• Front OEM muffler delete
• Mid OEM resonator delete
• Custom stainless steel axle back Y pipe with slightly larger oval sport muffler on left tail exit and kept the straight pipe on right tail exit
• Stock exhaust valve control module retrofitted to the right tail exit still in tact

https://cimg6.ibsrv.net/gimg/www.mbw...4e8e99745.jpeg

TLDR; All I can say is now I'm extremely happy. The exhaust now has a very nice deep tone, throaty growl and overall nice aggressive exhaust note. Also, the "boomy" sounding drone that I was previously experiencing has completely gone and the ride is now 99% drone free! I highly recommended exhaust mod for GLA35 / GLB35 owners who are after a bit more "aural pleasure" in their driving.

I have some videos to give an idea of the exhaust note on:

• start-up: warm start, Race mode with "emotion loud"/"loud start", with some revs
  https://1drv.ms/v/s!As9XKNqJDFbiw2onEyO6hbnZoS37
• some regular driving around different areas of Melbourne (roads ranging from 40km/h - 70km/h so no real aggressive driving to really show how spicy it can get)
  https://1drv.ms/v/s!As9XKNqJDFbiw2v9TzQgogxCG40K
  https://1drv.ms/v/s!As9XKNqJDFbiw2zOH7pzz-bx_4M1
  https://1drv.ms/v/s!As9XKNqJDFbiw27Rvc1wtWOJpj9m
  https://1drv.ms/v/s!As9XKNqJDFbiw22tVdNdxulK1Yly

Awesome work! curious, do you think the pops and bangs would be present if you had only removed the front muffler and middle resonator? And do you think there would be any drone with only those 2 removed?

thanks man. Yes I think that if you remove just the front muffler and middle resonator then you should unlock some pops and bangs because it will practically be the same as the A35/CLA35 exhaust setup but with a resonator delete done and the A35/CLA35 has pops and bangs from factory even without a resonator delete. I suspect that it’s the front muffler that kills the pops and bangs. no guarantees though. I had to play with my setup twice to get it where it is now.

so you could go with just the front muffler and mid resonator delete to see how it goes. If you like it then stick with it else do the custom axle back too ;)

In regards to drone with just the front muffler and resonator delete I think there will be no drone. I have no drone whatsoever with my setup.

did you get any notifications showing on your dash with the deletes?

nope. No EML / CEL on the dash at all. Would only happen if deleting cats.

That’s sounds nice. I assume it’s significantly quieter in Comfort mode?

I am also in Melbourne. Can you tell me where you got that done? And what it cost?

Does it void the warranty with MB?

thanks man. Yes it sounds much more quiet in Comfort and Sport. Only Sport+, Race and Individual are loud and only those modes have pops, bangs crackles and burbles.

Got it done at Tig Motorsports in Dandenong. Price wise, as mentioned it took 2 trips to get it to the configuration I wanted it:

1. $750 first trip with the smaller rear muffler and deleting front resonator.
2. $500 second trip to change to bigger muffler and middle resonator delete.

So if you get it done in a single trip it might be around $800-900 depending what you get done.

It will only void warranty pertaining to the exhaust system itself. But when it comes down to it, it will depend on how your service advisor, service manager and dealership are. Mine is amazing and have been awesome with everything warranty related.

Thanks

Still learning about this stuff. Is deleting any of the resonators illegal at all?

I’ve read that deleting the OPF is illegal. Is that the same thing?

Also read that it would be hard to get a RWC when selling the vehicle if this work is done?

I guess it really depends where you are located. In Australia, for me none of this was considered illegal (I didn’t remove cats or OPF/GPF).

Albeit if I absolutely fanged it in Sport+ or Race mode it’d probably alert EPA due to going over the allowed dB and they’d probably try to fine me.

All of what I’ve done is reversible do if RWC was something I’d need it wouldn’t be an issue. I could probably just get away with putting the OEM rear muffler back on.