Exhaust opinions...

[The Chauffeur]

Hey all, I'd like to hear your opinion on this:

My current exhaust setup is: Raceland shorty headers, single 2.5" resonator instead of cats (:devillook), then a cheapie 2.5 to 2.25 shorty muffler instead of the center OEM resonator (it was the only one that fit), and then an Eisenmann muffler; the whole setup probably weighs like half than stock!

The car feels really quick (for an E34 525 :D, of course), but the downside is that it sounds like utter crap! It's so noisy, I'm always self-aware of it, being extra gentle while shifting gears (especially between 1st and 2nd); I feel like it's not as enjoyable as before, as I have to keep my foot from making it sound like a rice bag... :shifty

I'm tempted to put the original exhaust back (minus the Racelands and the Eisenmann), but maaaan, that thing weighs a ton... I can almost see my poor car sinking in the ground like a Maus tank (and also being as quick as a Maus tank)... :(

Any thoughts?

[moroza]

Resonator delete on a BMW sounds like crap - raspy, buzzy, and with all the timbre of gaseous and slightly sticky bean digestion byproduct flying through a sawed-off tuba at 9000 RPM... Play with mufflers and pipes and headers all you want, but leave the resonators alone. I've read that BMW has an entire department dedicated exclusively to making its vehicles sound like a BMW; best believe they know what they're doing.

[The Chauffeur]

Resonator delete on a BMW sounds like crap - raspy, buzzy, and with all the timbre of gaseous and slightly sticky bean digestion byproduct flying through a sawed-off tuba at 9000 RPM... Play with mufflers and pipes and headers all you want, but leave the resonators alone. I've read that BMW has an entire department dedicated exclusively to making its vehicles sound like a BMW; best believe they know what they're doing.

I know... If the OEM resonator would have fit with the cat "replacement", I'd have left it in place... :(

[GregT53]

Stock except for an Eisenman sounds great on my '95 525. Can you leave the cat out of the system or do you have emissions checks in your part of NC?

[The Chauffeur]

Stock except for an Eisenman sounds great on my '95 525. Can you leave the cat out of the system or do you have emissions checks in your part of NC?

We don't have emissions here for OBDI cars, but they do run a visual inspection; that's why I put that front resonator, it's the only one I've found that looks like a cat, too bad it doesn't have the same size and layout as the OEM ones... :(

[moroza]

Why don't you put the cat back on and cut pollution while you're at it? This isn't a domestic from 1975; the cats don't hurt anything.

[The Chauffeur]

Why don't you put the cat back on and cut pollution while you're at it? This isn't a domestic from 1975; the cats don't hurt anything.

Why don't you get a Prius instead of an E34? :lol3

[fo3]

TL;DR: What's the best replacement of the rear muffler to shut the thing up - instead of the stock ANSA BW8017 which is AU ~$500? No decent custom guys I used to know are still in business.

I'm interested in this topic because my e34 is pretty loud - in an obnoxious a blowy/farting kind of way.

Resonator delete on a BMW sounds like crap - raspy, buzzy, and with all the timbre of gaseous and slightly sticky bean digestion byproduct flying through a sawed-off tuba at 9000 RPM... Play with mufflers and pipes and headers all you want, but leave the resonators alone. I've read that BMW has an entire department dedicated exclusively to making its vehicles sound like a BMW; best believe they know what they're doing. Yeah like this.
I'm now wondering if it is the rear muffler faut or a blown resonator now :(

It's all stock, and flow seems OK. No reason to throw out the Cats if they are not restricting. I've had plenty of newer cars with blocked Cats and the flow being obstructed so I know when that happens.

Also I'm old, in Australia unleaded fuel (and Cats) didn't happen here until 1986, and leaded fuel was available until 1995 or something like that. Things were good for my extend port 13B, bridgeport 13B and turbo 12A until 1995

Being the type of person that bought an e34 in 2017 I can guarantee I was the type of person driving Cat-less 1970s cars from 1990-2005. It was awful when I had to run them on unleaded fuel. I can still tell there's a Cat-less car modified way up the road. You never forget that headache and smell, either in the car, or as an unfortunate member of the public that car passed by, or worst of all a fellow driver stuck behind that car on a long commute. Never forget.

Anyway, just by that long time life experience I have nothing against my e34 Cats because I really know if they aren't functional or are blocked. They don't seem to be which is amazing. I had a 2006 model domestic car fully blocked, lost all power and kept running until the gearbox was almost toasted so I know all the signs of a restricted Cat now.
I really need to replace the rear muffler though which is probably blocked and useless and makes all the bad noises. It's the factory ANSA BW8017 with the long twin pipe up the floor pan and about AU$500.
Most of the independent exhaust shops I used to know in the 90s for my old Cat-less builds are all closed or only doing big $$$$ turbo or v8 stuff now plus I really need to be squirreling away money for a engine rebuild due to that stupid hot slap sound my motor makes now.

[The Chauffeur]

I've been there, trust me (ergo the reason of this thread :stickoutt); I agree, OEM replacements are crazy expensive, and every year seems to be fewer and fewer aftermarket options for our cars, and most of the ones available are pricy performance ones.

Best bet IMHO would be to try and get good used ones, which also seems to be getting more and more difficult every day...

[demetk]

On my e28, I used a Magnalow 4"x26" round bullet resonator ($25) with a Walker 6" round chambered muffler ($24) with single 2.5" tubing for a total cost of about $100. Nice and quiet. Planning a similar setup on my e34 but in stainless steel. For quiet sound you really need a chambered muffler vs a straight through muffler.

[The Chauffeur]

And more chambers the better! The one I have right now in place of the resonator is a shorty V-flow single chamber (as I said previously, it was the only one that fit); I hate it, makes it sound like a badly tuned truck V8... :(