When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
AMG GLA35 (2021) | Patagonia Red | AMG Aero, Vision & Innovation Packages | 21" AMG Matte Black Rims
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.
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.
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
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:
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?
AMG GLA35 (2021) | Patagonia Red | AMG Aero, Vision & Innovation Packages | 21" AMG Matte Black Rims
Originally Posted by dannyjak
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.
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.
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.
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
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:
AMG GLA35 (2021) | Patagonia Red | AMG Aero, Vision & Innovation Packages | 21" AMG Matte Black Rims
Originally Posted by AnthG
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:
$750 first trip with the smaller rear muffler and deleting front resonator.
$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.
AMG GLA35 (2021) | Patagonia Red | AMG Aero, Vision & Innovation Packages | 21" AMG Matte Black Rims
Originally Posted by AnthG
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.
I saw in the video you posted, that you switch the car into RACE mode. How did you unlock race mode?
I've just got my GLB35, but I can only go up to Sport+
Also probs on the exhaust mod, you saved the rest of the community a lot of time. Gonna get mine done pretty soon. I'm gonna keep the rear muffler for now, and just have the middle muffler and resonator deleted to get some pops.
Glad I found your post here, new member/new car -- 2024 AMG GLB 35, purchased January 2025. Within days of making the purchase and having already found and saved your post here about the mods in Melbourne, I took my car to trusted local shop and immediately had the front (smaller) muffler and resonator removed (cat back). I figured I would try this before tackling the rear larger muffler (that thing's huge).
Three weeks later now and I am super happy with the sound, the pops/crackles, and the more visceral sound and attitude of the GLB 35. I have not noticed any droning or other unwanted sounds so I think (at least for now, for this year) I'm super happy. (Note too, for clarification, I also didn't do anything to the OEM valve motor / control unit.)
Again, thanks for the post and insight, photos, videos -- made me a believer.
I've also had the mid box deleted on mine. Mine is an EU model so it has an OPF filter in the front, instead of a mid box and a resonator.
Deleting the mid box brought out some pops and bang on downshift (above 3500 rpm), but the overall volume didn't increase at all.
The OPF and the rear box are restrictive enough to kill most of the fun, not to mention that the valve stays closed when I'm under ~3000 rpm.
I will soon get a full cat back exhaust soon with aftermarket valves. There are plenty of well knowns exhaust brands making systems for the GLB but they are honestly ridiculously expensive. I will get a cheap system from China first (400 dollars + shipping), and if I'm not happy with it, then I'll get a Capristo of FI exhaust system, but I wouldn't really want to fork out 6000+ dollars for some basic tubes and two valves... Huge OPF that kills most of the sound
Deleted mid box
Last edited by BanatiBarna; Feb 17, 2025 at 09:22 AM.
Hi everyone,
Thank you so much for sharing this. I just picked up a 2021 GLB35 in the UK and am seriously considering improving the sound.
I've noticed the engine note is being pushed through the speakers, so I'm looking at having that coded out.
I then want to customise the exhaust. I like what you've achieved just by removing the front and mid box, my only concern is I would still like it quite in comfort mode and I'm not after a deep bass tone at idle or low revs.
Last edited by Mr.Gheewala; Feb 26, 2025 at 06:26 PM.
Hi everyone,
Thank you so much for sharing this. I just picked up a 2021 GLB35 in the UK and am seriously considering improving the sound.
I've noticed the engine note is being pushed through the speakers, so I'm looking at having that coded out.
I then want to customise the exhaust. I like what you've achieved just by removing the front and mid box, my only concern is I would still like it quite in comfort mode and I'm not after a deep bass tone at idle or low revs.
You don't have to worry about drone at low revs. If you only delete the mid box and resonator (however I believe UK models also have an OPF instead of a box) you won't get any more volume or drone.
Even if you go to a full catback system, the volume will be very close to stock with the valves closed.
Thankss for that. It's illegal here to get rid of the OPF so 😔. I have found a couple of reputable exhaust places near me so will pay them a visit.
It's technically illegal here too, but no one cares about it during the mechanical inspections as long as the exhaust looks stock from behind.
I even asked my local Mercedes representative and they said it doesn't even effect the warranty, they don't care if I change the exhaust. Of course the aftermarket exhaust isn't covered my the Mercedes warranty, but I don't think anyone expects that.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
