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The noise coming from my exhaust is too loud and I would like to muffle this.

I have a stainless steel middle silencer and end silencer, I think from Ireland Engineering.
And an aftermarket catalyst, brand unknown perhaps Magnaflow??

I have the impression that the middle silencer is hollow, when I tap it I hear no damping at all, the exhaust seems to have some damping when I tap it.

Does anyone have a good idea how to muffle it? I was thinking of cutting out the middle silencer and replace it with another one, but which one?
I don't want to completely replace the existing system with an original BMW system, that costs way too much.

It's a BMW 635CSI, 1987 with catalytic converter (USA model).

Took the Ireland exhaust out.
The middle silencer sounds hollow on all spots where I tap it. The pipes are straight through. I don't think it will muffle much.
Thinking of cutting out this silencer and weld in a replacement silencer of a more quiet type. Saw some nice models of the brand Flowmaster, which will do the trick I assume.

Looking at your second photo, it appears that you also have headers

And the collectors have been joined into one larger pipe, then into the cat, followed by a resonator that doesn't appear to be doing anything according to you, then finally the muffler

If you are sure that the exhaust is from Ireland Engineering, why not contact them for advice

I have a "similar" setup, thanks to the previous owner having installed Stahl long tube headers, which have been a royal PITA to deal with, but I still have them on

Here's a shot from front to back, wherein you can see that the headers end beyond the tranny

After the cat, I have a short resonator, I'd have to find the receipt for the name of the manufacturer, but I'm fairly certain it wasn't even for a 6er

Anyhoo, think I'd start with Ireland before doing anything else

Bobbo may be able to chime in here but I am not sure if I saw it here or on another forum. It was a type of resonator that absorbed or deadened sound and controlled exhaust noise.Maybe by googling around looking for exhaust sound absorber or some such it might pop up up. They very large and could easily be fitted into your system. i have a Billy Boat system which may prove to be too noisy and I will end up looking for these They appear to be a legitimate solution

Hey guys, thanks for your replies.
Good idea, I have emailed Ireland right away, will have to wait for their reply.
Do I see it correctly that you have an ellips shaped end muffler? I would assume they will not fit.

I searched the internet for this absorber, but I am not able to find it. Or more precise I am not quite sure what I am looking for so perhaps I did not recognize it. Doesn't it look like a muffler?

The rear muffler is actually kind of "square" cross section, more tall than wide I think, in fact it's also what's left of my Billy Boat (B & B TriFlo) system that I tried years ago

Bert and myself have been round and round about these systems, they are still using glass packs for a resonator, talk about loud

And the drone, they had to go

Bert can probably confirm the shape of the rear muffler, I can always take photo as well, if you need

Lemme know

Oh, OK, now I see.
It is this muffler right? https://www.lmperformance.com/images/pa ... -0720e.jpg
So these are quite loud as well. Are there any aftermarket exhausts on the market which aren't?
I see some Italian brands making more stock look-a-like mufflers (ASSO, ANSA) and also the mufflers of Walker. Anybody has experience with these?

That is the muffler we are talking about.

Contacted Ireland, they confirmed it is their exhaust. They mentioned that this is just how it sounds and that they cannot help me reducing the noice.
Well, I am quite sure some younger folks love the sound coming from it , but for me as a 40-er it is too loud.

I bought a middle silencer of a 5 series, type E34.
In terms of dimensions and tubes, this is the same as the middle silencer of Ireland (it took me a few hours of research to find it! ).
This has considerably more damping than the silencer that is now on the car. According to the manufacturer of the E34 exhaust, is sounds simular to an original middle silencer.

Just cut and weld it and run a test!

I hope this reduces the noise. My 6-er does not have to be quiet, but a few DB's less would be great.

Guys, just wanted to let you know that welding in this E34 silencer worked out pretty good.
The noise is reduced by some dB's making it much better.
It still isn't a quite car, but now it is just fine, not so loud anymore.

Does anyone have experience with these direct-fit aftermarket exhausts?
Wonder if these produce an identical sound as an original rear silencer.

https://www.ebay.com/itm/Auspuff-Endtop ... SwOVhgM6sy

I built my own exhaust, and my setup runs a Moroso spiral flow as a center resonator, then a Magnaflow DBX at the tail end. The combination pulls the drone out of the pipe, but leaves it with a deep burble and some bark on decel. I feel that is an ideal combination.

Jose

Thanks for your input Jose.
Good solution with the Magnaflow DBX, not many silencers fit in the narrow passage that the E24 has.
Can imagine it produces a great sound, but I think it will be too sporty for me.
I am looking for an original sounding solution, not too much noise but still the typical BMW 6 cylinder sound. The best would be original, but not everything is available anymore and if it is, it costs way too much.

If you are hunting for a nice, and quiet solution then stay away from all the performance biggies (Borla, Magnaflow, Flowmaster, etc.). From what I have read, Walker is supposed to make a bunch of versions with a goal of being quiet first. You should check out their site and see if anything could be made to fit.

Jose

That's good to know! Then a Walker might be a good option for me.
Walker also makes a direct-fit aftermarket muffler for the E24, the Walker 13033

This is the Walker exhaust:
https://www.buycarparts.co.uk/walker/1004983

If you go to the Walker site, and look up your car, they seem to sell a complete system as well that includes a catalytic.

Jose

I finally have the sound I wanted, the exhaust system now sounds really great in my opinion.
Beautiful humming 6 cylinder sound.

What I've done:
- New aftermarket catalytic converter from a 5-series, type E39 / 7-series E38 (BMW part no. 18301745010)
- New Bosch oxygen sensor (Bosch part no. 0258986502)
- New aftermarket middle silencer from a 5-series, type E34 (matches BMW part no. 18121719426)
- New E24 rear silencer from Walker (Walker part no. 13033) (Thanks for the tip Da_Hose)
- I re-used some tubing of the middle silencer of Ireland Engineering, this could be made with some standard bend tubing as well.

I cut the silencer and catalytic converter of the 5-series into pieces, hung it in rubbers as far as possible and spot welded it under the car. Then disassembled and completely welded it. The exhaust is mounted neatly tension-free.

For the rear silencer I am about to order chrome end pieces, if possible original BMW.

That's a good looking end result.

Jose

Da_Hose wrote: ↑Tue Apr 06, 2021 3:10 pm That's a good looking end result.

Jose

Thanks Jose!

Finished!
Fitted 2 original BMW chrome tail pipe tips.

Is the 635 different from an '84 633Csi? I need a new rear section.

Sansouci,


This is 633 8/84

https://www.realoem.com/bmw/enUS/partgr ... 3CSi&mg=18

This is 635 8/84

https://www.realoem.com/bmw/enUS/partgr ... 5CSi&mg=18

The Walker 13033 muffler I bought is for the 628.
It did fit my 635 perfectly in terms of shape and the size of the tubes, except for the bracket, I think on the older models it was clamped around the exhaust. In my case, however, there was a bracket welded to the exhaust just above the end pieces.
I made and welded that bracket myself (see photo).

I don't know if you can also make it to fit a 633, but I assume that if you can weld it should be possible.