Deleted Cat suggestions

E28 technical advice asked and given! Troubleshooting, modifications and more.
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blockerb
Posts: 127
Joined: Apr 28, 2011 9:58 AM

Deleted Cat suggestions

Post by blockerb »

I have a 1986 528e automatic. OD stopped at around 104k but suspect its in the 180k range realistically. All runs great. However, the PO deleted the cat and straigt-piped it back to the OEM muffler. However, the did a shitty job welding in the straight pipe where the cat used to be so it sounds a bit "throaty" and "trucky" due to the lack of a cat/resonator and gaps in the straight pipe connection.

Question is does anyone have a suggestion to restore the factory sounds as close as possible. Not looking for anything sporty or loud. just factory preferred....I know, boring :) Been looking around the board for a while and find mostly suggestions involving more elaborate solutions designed to be more sport sounding or throaty....

I'm working on sourcing an OG cat from someone on marketplace but proving challenging to pull the trigger and I'm in Atlanta and the OG cat is in Portland. Definitely my first preference but given that its a used OG cat I'd assume there's a risk it could fail fairly soon, although the seller says its from a lower miles 528e (~65k i think).

Any suggestions on a solid replacement for the cat. I don't need to worry about emissions testing for this car in Atlanta, so if there's a non-cat option then I'm open to that.
athayer187
Posts: 1621
Joined: May 10, 2006 11:27 AM
Location: Cheshire, CT

Re: Deleted Cat suggestions

Post by athayer187 »

If emissions aren't a concern, why not just throw a resonator or small muffler in that location?

https://www.amazon.com/Vibrant-1140-Ult ... B000E3VHW8
blockerb
Posts: 127
Joined: Apr 28, 2011 9:58 AM

Re: Deleted Cat suggestions

Post by blockerb »

athayer187 wrote: Jun 07, 2023 12:02 PM If emissions aren't a concern, why not just throw a resonator or small muffler in that location?

https://www.amazon.com/Vibrant-1140-Ult ... B000E3VHW8
Interesting I didn't know that was available. i don't have to worry about emissions for this car here in GA. I guess i would just have shop "properly" weld that in where a cat would have gone? Any experience with something like this?
athayer187
Posts: 1621
Joined: May 10, 2006 11:27 AM
Location: Cheshire, CT

Re: Deleted Cat suggestions

Post by athayer187 »

Not in my E28, but in my E30/S54 race car we always use resonators like that to increase backpressure slightly and attenuate the exhaust note. You'd be surprised how much of a difference adding a resonator makes. We race at tracks with significant noise restrictions (in the Northeast), so it's really important to us.
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