Rear Muffler

[Alexlind123]

I have been thinking about replacing my rear muffler with something a bit more "exciting" Does anyone have any video or coud clips of m30 exhaust? I would like some feedback as to what any of you might have tried and how you fele about it.

[BigKriss]

straight pipe it

[shogun]

glasspacks. Go to roadfly E32 board and see the picture gallery E32. I posted there pics of the glasspacks they made for a 735 E32. Complete exhaust is shown there and while they weld it.

[willobmw]

I got an Eisenmann Sport performance (old version) on mine. At idle it has a nice mellow tone. It only roars at full song. There is presently a rare ANSA muffler on Fleabay for the 535i with dual 3 inch pipes. Never had lasting success with the ANSA on my 2002 as mentioned in another post because they typically rust inside out sooner than others. Good price though and it should sound pretty good.
Willobmw
1990 535i
1981 528i
1975 2002

[Scott H]

and removed the center resonator and replaced it with stainless steel straight pipes.....

The wife could always hear me coming from 1/2 mile away. The drone inside the car was worse than the exhaust actually sounded. Maybe if I had left the center resonator in it would have been more tame.

After I get done with the 535iT project, that same exhaust will go on that car. :D I'll try to take some video when the project is done.....mid Jan. I might be too late by then for your purposes though.



I have been thinking about replacing my rear muffler with something a bit more "exciting" Does anyone have any video or coud clips of m30 exhaust? I would like some feedback as to what any of you might have tried and how you fele about it.

[Johntee540]

I like the Billy Boat Tri-Flo Exhaust. It is inperceptible inside the car except during acceleration. But sounds really nice outside the car. It is on sale i think at BavAuto. (no affiliation) otherwise talk to dennis hannes at Billy boat (no affliliation) - JT

[Scott H]

He's looking for 535 application. A buddy of mine has a Tri-Flow on his 1990 535 and I'd say the interior noise is definitely perceptable. In fact, it's a shade below my setup and he has a center resonator whereas I don't.

I think Martin B or Jeff N have a Tri-Flow that they took off their car....they can opine on using this long term.



I like the Billy Boat Tri-Flo Exhaust. It is inperceptible inside the car except during acceleration. But sounds really nice outside the car. It is on sale i think at BavAuto. (no affiliation) otherwise talk to dennis hannes at Billy boat (no affliliation) - JT

[NY535iManual]

I have the tri-flow on my 89 535. At dead idle it is pretty quiet.

Driving, it is definitely noticeable inside the car, but not to my mind bothersome unless you have the windows down on the highway: Then the exhaust plus wind noise can be tiring on long drives. It does however sound really cool to hear the back-pressure clear when you lift, almost like a turbo car's boost over-run after a down shift.

Outside is another matter - Its pretty loud. I like it, as I can always hear the car coming when a parking lot attendant is pulling it out of my building's garage. You can also hear it from down the street, but it is a nice rumble, not the nasal buzz that comes out of some kid's "Fast and Furious" four-banger.

[Incantation]

two audio clips of mine. i have stock exhaust plus a magnaflow muffler

1st is a jonk type file where the car sits idling and revving (lawlz?)

http://media.putfile.com/idling-exhaust-m30magnaflow

2nd is chasing a buddy on his bike (windows open)

http://media.putfile.com/exhaust-note-02---m30magnaflow

it is a bit loud for my taste, but it's nice and throaty. of course i usually have the music up so loud i can't hear anything anyway

[Scott H]

Am I hearing a lot of piston slap in that first audio clip?



two audio clips of mine. i have stock exhaust plus a magnaflow muffler

1st is a jonk type file where the car sits idling and revving (lawlz?)

http://media.putfile.com/idling-exhaust-m30magnaflow

2nd is chasing a buddy on his bike (windows open)

http://media.putfile.com/exhaust-note-02---m30magnaflow

it is a bit loud for my taste, but it's nice and throaty. of course i usually have the music up so loud i can't hear anything anyway

[Dave Rutkowski]

But I think Triflow came out with a "quiet" version in the last couple of years, so they may be better now. I think the best bet might be running a cat, straightpipes instead of the resonator, and then a stock muffler. That's the setup I have on my '81 635 and it sounds great - more snarl and less drone than the Triflow.

Dave Rutkowski
'90 535iM
'81 635CSi (euro)

[Martin in Bellevue]

Sounded like rod knock to me.

Am I hearing a lot of piston slap in that first audio clip?

[Martin in Bellevue]

After listening a couple times, I'm more concerned with lower bearing noise.

Maybe the valve cover could be pulled to check the rockers; they do fail above repeated 6k rpm use. The lower bearng noise might be accompanied by slow oil pressure light at cold startup, or possibly oil pressure light at idle.

Hmm.


Sounded like rod knock to me.

[Scott H]

Oil pumps can wear out as well...Mine was putting out 7psi at idle which, although is in spec, was too low to supply proper oil to the far reaches of the valvetrain.

I would say low oil pressure at start up and at idle is contributing to such things. Tim C is replacing his oil pump soon as well on a seasoned M30

Hmmm..


After listening a couple times, I'm more concerned with lower bearing noise.

Maybe the valve cover could be pulled to check the rockers; they do fail above repeated 6k rpm use. The lower bearng noise might be accompanied by slow oil pressure light at cold startup, or possibly oil pressure light at idle.

Hmm.

[Martin in Bellevue]

Oil pumps can wear out as well...Mine was putting out 7psi at idle which, although is in spec, was too low to supply proper oil to the far reaches of the valvetrain.

I would say low oil pressure at start up and at idle is contributing to such things. Tim C is replacing his oil pump soon as well on a seasoned M30

Hmmm..
Is the issue a weak oil pump, or crap clearances on the main bearings?

I guess that ominous noise could be just about anywhere in the bottom end.

[Martin in Bellevue]

Maybe an oil analysis from blackstone labs would help identify the type of lower end damage done here?
The bearings would leech off nickel. Fragments would indicate other issues, as well.

[Scott H]

The bearings would also give off lead as well. The synthetic oils have so many additives that it is hard to read those oil analysis anymore!! The last one from my M30 left me believing the whole engine was breaking apart!!!

When I took my engine apart I found a nice four-corner score on the cylinder walls and scuffed up pistons skirts. It was the result of piston slap and it will be interesting to see if I can keep the cylinders and pistons without boring the block out and replacing pistons as that is $$$$$.


Maybe an oil analysis from blackstone labs would help identify the type of lower end damage done here?
The bearings would leech off nickel. Fragments would indicate other issues, as well.

[Martin in Bellevue]

The bearings would also give off lead as well. The synthetic oils have so many additives that it is hard to read those oil analysis anymore!! The last one from my M30 left me believing the whole engine was breaking apart!!!

When I took my engine apart I found a nice four-corner score on the cylinder walls and scuffed up pistons skirts. It was the result of piston slap and it will be interesting to see if I can keep the cylinders and pistons without boring the block out and replacing pistons as that is $$$$$.

Yep, it may be the time to investigate cylinder wear & possibly step up to 3.7l pistons.

Are new lower bearings & caps available directly from the dealer?

[Scott H]

I have a crank set and a rod set for my rebuild...Unfortunately the dealer sells them individually and they add up FAST!

The caps have to come from germany and cause quite the wait.


Yep, it may be the time to investigate cylinder wear & possibly step up to 3.7l pistons.

Are new lower bearings & caps available directly from the dealer?

[Martin in Bellevue]

BMW really bends ya over the fender with those metric prices on motor parts.


I have a crank set and a rod set for my rebuild...Unfortunately the dealer sells them individually and they add up FAST!

The caps have to come from germany and cause quite the wait.

[Jon K]

I am not sure - the piston slap sounds more like the oil sprayer bar bolts are rattling around in the head. Apparently if you rev to 7000 you can vaporize the steel bolts and not have to pop the valve cover off.

[Incantation]

about 150k maybe..

that noise is something outside the engine.. the guy from whom i bought the bmw, a close family friend, also owner/operator of a bmw dealership with combined 100 years of experience in the shop said it's nothing to be concerned about

[Scott H]

just found it to be quite prominent as the rpms came down towards the end of the clip. I had the same on my 535 with 146k on it....just not as loud. It really was piston slap. We analyzed the crap out of it before and after taking my engine apart. The M30 block is big time durable and can handle it as there can be some slap in these engines as they age, but it's still nice to know what is going on. I'm just saying don't ignore it as it will help in case there IS an issue in the future....pay attention to it.

Oh...the guy I analyzed my motor with has a PhD from Northwestern and owns a data acquisition company in the motorsports field. Him and his father have a combined 60 years of experience building porsche and bmw engines as well as a client list with IRL, Champ, nascar, etc etc....basically anything with a motor and wheels/treads/propellers.

I was not ********ting about what I thought I heard....



about 150k maybe..

that noise is something outside the engine.. the guy from whom i bought the bmw, a close family friend, also owner/operator of a bmw dealership with combined 100 years of experience in the shop said it's nothing to be concerned about

[Martin in Bellevue]

about 150k maybe..

that noise is something outside the engine.. the guy from whom i bought the bmw, a close family friend, also owner/operator of a bmw dealership with combined 100 years of experience in the shop said it's nothing to be concerned about

Did the seller happen to know what the noise was? It seems to be a sound that could be indicative of problems in the motor.

You're really not interested in isolating the cause?

[Incantation]

that's interesting.. yea the noise is annoying but it comes from a pulley or something.. shrug. i would prefer it not be there but it's been around since i got the car at 89k and it only does it if i rev the engine in neutral which is basically never

[Incantation]

yea he did.. i can't recall what it was. i can't say i'm not interested in isolating the cause.. it's not something that is wrecking the system (apparently), and i never hear it because i never rev the motor.. so it's not really a priority. having said that if someone knows how to fix it i will do it.