[AZE93M3]

Hi everyone, making my first post here. I have spent hours searching old threads, but want to get some advice specific to my vehicle.

I have a completely stock 2009 E93/convertible manual 335i that I wanted to give a little more aggressive exhaust, without any drone. Did the golf tee mod, still a bit quiet for me. Downpipes will remain stock, don't want to work around emissions. Opted not to go for PE mod because I wanted to replace tips anyways and felt shedding a few pounds couldn't hurt.

I replaced the stock mufflers with Vibrant 1141 Ultra Quiet resonators, expecting to get a bit more exhaust noise without the drone, and lose a few pounds on the rear axle. Added some aftermarket 3.5" tips. The setup is actually much quieter than I was expecting for essentially a muffler delete, but it drones horribly under load between 1800-2200 RPM. I need to change something, open to suggestions.

Questions I have are:

1. Is it possible that swapping out the secondary cats for Vibrant 1792 resonators would possibly help the drone? I saw robc1976's post with this setup (with DPs) and he didn't note any drone, but it seems counter-intuitive that removing cat would make this sound better. (https://www.e90post.com/forums/showt...=859463&page=2)

2. If not the 1792's, is there another bottle style muffler (not resonator) I could install where the secondaries are to reduce the drone?

3. Is there an aftermarket muffler I can swap in instead of the 1141's I have now that will give me some more sound (vs. stock) without drone, still saving a few pounds? Trying to keep it relatively cheap with an off the shelf magnaflow or something similar, not a $1000 axle-back exhaust system.

4. I think my solution may be electric cutouts. I am wary of the one-sided straight pipe solutions (https://valvetronic.com/products/bmw...muffler-bypass) due to flow constraint when the valve is closed, but could be convinced otherwise. I think option 3 plus cutouts may be the ticket, as it seems there is simply not room for cutouts with the stock muffler without some serious modification/handiwork I can't expect from a local shop.

5. J-Pipes are frequently suggested, I could potentially add to my current setup, but wary that could be a lot of time/trial and error/cost

Thank you all in advance for any tips or suggestions, and Happy New Year!

[Bimmer_Engineer]

Resonators aren’t mufflers...if I were you I’d put the mufflers back on and replace the secondary cats with resonators. If you still want more sound then consider the PE mod on the mufflers...

[lookalikehuuh]

I had my stock mufflers gutted and they sound pretty decent. No drone at all either.

[BSM n54iS]

Get new dp's

[N0Chill 335i]

I had this same setup on my 2007 e92 6 years ago. I initially did a muffler delete and it was terrible for drone in that same range. I did the 1792 secondary cat replacement and 1141 ultra quiet and loved it. Drone was greatly reduced, but still noticeable at certain highway speeds. You can look into J Pipes for the Helmholtz effect to negate the drone. There are some RPM calculators that you can use to target your exact drone level you want to eliminate. They work best when perpendicular to the exhaust piping which can be difficult with the limited space on these cars.

[AZE93M3]

Originally Posted by N0Chill 335i

I had this same setup on my 2007 e92 6 years ago. I initially did a muffler delete and it was terrible for drone in that same range. I did the 1792 secondary cat replacement and 1141 ultra quiet and loved it. Drone was greatly reduced, but still noticeable at certain highway speeds. You can look into J Pipes for the Helmholtz effect to negate the drone. There are some RPM calculators that you can use to target your exact drone level you want to eliminate. They work best when perpendicular to the exhaust piping which can be difficult with the limited space on these cars.

Thanks for the feedback. What do you define as highway speed? With just the 1141's in place I have no drone above about 2200 RPM in 6th gear, quiet as stock on the highway I'd say. My main concern is 4th gear around 2000rpm, as that's the majority of my regular daily driving. It sounds like it probably makes sense to "finish" the setup I have and put the 1792's on, willing to take the chance the resonators will drone less than the secondary cats.

Thanks again for all the help, everyone.

[N0Chill 335i]

Originally Posted by AZN54335i

Thanks for the feedback. What do you define as highway speed? With just the 1141's in place I have no drone above about 2200 RPM in 6th gear, quiet as stock on the highway I'd say. My main concern is 4th gear around 2000rpm, as that's the majority of my regular daily driving. It sounds like it probably makes sense to "finish" the setup I have and put the 1792's on, willing to take the chance the resonators will drone less than the secondary cats.

Thanks again for all the help, everyone.

If I can remember correctly it was right around 80mph in 6th gear. Again, it was minimal compared to what most people would consider drone. I'm actually in the process of doing a very similar setup for my N55 e92 right now. Putting together all of my individual components to order in a few weeks. I recall wanting to drive off a bridge with the muffler delete... but the 1141/1792 setup was pretty damn great. I did 3" piping all the way through but I'm not sure what effect that had on the sound. Hopefully it solves your issue with the resonators in place. I'm also currently doing research on X-pipes to see what benefits it will have in terms of sound, if any.

[Emilime75]

I'd go with 335is mufflers and golf tee mod. Rumor has it they are the same as PE, but include the valve like the stock exhaust. This added just enough noise to my otherwise stock 335i, along with a touch of burble and I don't get any drone. If this isn't enough for you, then replace the cats with resonators.

[AZE93M3]

I just ordered the 1792's and will replace my 2nd cats with them. If that is still too much drone, will put the stock mufflers back on and keep the slight bump in sound from the 1792's. I am really hoping the 1141 + 1792 combo, with my stock DP and stock X-pipe, will keep the drone minimal. Will update once installed. Thanks for the help again.

[mweisdorfer]

Originally Posted by AZN54335i

I just ordered the 1792's and will replace my 2nd cats with them. If that is still too much drone, will put the stock mufflers back on and keep the slight bump in sound from the 1792's. I am really hoping the 1141 + 1792 combo, with my stock DP and stock X-pipe, will keep the drone minimal. Will update once installed. Thanks for the help again.

Just get a used set of 335is mufflers or a used set of PE mufflers in addition to the vibrant 1792 & you will pleasantly surprised.

[AZE93M3]

The 1792's did not help the drone. I am going to re-install the stock mufflers and have electric cutouts welded in just before them. I think that will solve all my issues.

[ludoN54]

Hi !!

I have a 335i with downpipe and full exhaust ( top speed race exhaust)
the car is really drony and i just purchased valved muffler, will keep you updated

but i think i will have to replace current resonator with Vibrant ultra quiet resonator

[ludoN54]

i purchased this =>https://xforceusa.com/varex-mufflers/

sound test with top speed exhaust =>

[ky0u]

Originally Posted by AZN54335i

The 1792's did not help the drone. I am going to re-install the stock mufflers and have electric cutouts welded in just before them. I think that will solve all my issues.

Originally Posted by ludoN54

Hi !!

I have a 335i with downpipe and full exhaust ( top speed race exhaust)
the car is really drony and i just purchased valved muffler, will keep you updated

but i think i will have to replace current resonator with Vibrant ultra quiet resonator

My set up under normal acceleration:

Secondaries deleted and replaced with vibrant resonators. 335is mufflers with golf tee mod

[TheMidnightNarwhal]

I think muffler helps with drone. I have catless DPs, second cat deleted replaced with reso and the rest is stock.

[TheMidnightNarwhal]

Originally Posted by ky0u

My set up under normal acceleration:

Secondaries deleted and replaced with vibrant resonators. 335is mufflers with golf tee mod

How do you record? Do you have a go pro?

[ky0u]

Originally Posted by TheMidnightNarwhal

I think muffler helps with drone. I have catless DPs, second cat deleted replaced with reso and the rest is stock.

I think the resonators in place of secondaries make a huge difference as well with cleaning up the sound. Almost everyone I've seen complain of drone has both primary and secondary cats outright deleted

Originally Posted by TheMidnightNarwhal

How do you record? Do you have a go pro?

Yes it was a go pro mounted on the bumper.

[Emilime75]

Originally Posted by ky0u

My set up under normal acceleration:

Secondaries deleted and replaced with vibrant resonators. 335is mufflers with golf tee mod

Stock or catless downpipes?

[ky0u]

Originally Posted by Emilime75

Stock or catless downpipes?

Still got the stock DPs on there. I believe OP was planning on leaving their's stock too for inspections

[TheMidnightNarwhal]

Originally Posted by ky0u

I think the resonators in place of secondaries make a huge difference as well with cleaning up the sound. Almost everyone I've seen complain of drone has both primary and secondary cats outright deleted



Yes it was a go pro mounted on the bumper.

Yeah I did it more for rasp so I can't recall how it was before... but I'm surprised how quiet my car is sometimes and when I floor how loud it is.

I miss hearing it from outside that's why I wanted to record clips to hear how it sounds .

[ludoN54]

varex valved muffler solved my drone issue

[AZE93M3]

If anyone is interested in purchasing the resonator setup, link here: https://www.e90post.com/forums/showthread.php?t=1793894