New Exhaust?

scottevest

scottevest

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I am considering doing some work on my 74 3.0cs. It runs great now, but I really don't care for the sound from the exhaust. I prefer a throaty, deep, growl . Any suggestions on how to accomplish this. I don't care if it increases performance so much as sounds good and sporty. I don't mind it slightly loud either. If someone has addressed this question before, please point me to the best thread. I plan to do some searching now.

I have been taking my coupe out on nice days and really enjoying it.

Scott
 
Scott - Are you running a 3.0 or 3.5 liter engine? Coupeking has a louder stainless system for the 3.5 liter. I have also come up with an alternative (quieter than CK) stainless for the 3.5. A smaller rear muffler would make it louder. If you have the stock 3.0 system you could try swapping out the rear muffler for a smaller Magnaflow unit. This would require some redoing of the rear pipes as well.
 
I have the orig 3.0 engine

I would love to get an M engine someday, but for now I think the 3.0 has plenty of power. Just need it to sound better
 
if your exhaust is stock, first have a muffler shop cut out the center resonator, I did this and got immediate throaty sound for $25.
 
I had that done already

That was done sometime ago and it improve things but now I want and even throatier sound. Is there any shortcuts to this with the understanding that I am not looking necessarily for performance but only sound?
 
should i post this on just a BMW forum since this is not specific to e9

I was thinking of posting this question to just another bmw forum. Do you have any recommendations of another top bmw forum? Also, this may be a stupid question, but has anyone tried to put a more recent smaller bmw engine into their coupe. There are some pretty good bmw engines less than 3.0 liters.
 
The electronics are extremely complicated on newer BMW engines. I looked into swapping a 3.2 M3 motor into my E46 Wagon and balked at the complexity. I would have had to take my dash board apart.
 
You may like the Magnaflow. Wayne posted a nice sound comparison on YouTube awhile back. Borla and Anza also have rear cans which might fit. IIRC, 6"x18" is what you want.
 
Just got my car back and it sounds fantastic

I just got my car back. It sounds unbelievable. Much better sounding then I thought it would based upon the videos I have seen and heard. I highly recommend this. I would've done this much sooner. It makes the car seems faster although it is hard to tell that actually it is but it sure does sound that way. I also purchased the springs from coupe king. Erik is a great guy and highly recommended. The car looks lower now and appears to ride better although I did not drive that far.

My mechanic indicated that there was some coolant in the old exhaust which might begin to explain my coolant issues. It appears that there might be a crack in my case after all. As a result, I am in the market for a rebuild 3.5 engine. Does anyone know of a good source for this.

Coupe king said that he could source in the engine for me and send for my mechanic to install. Let me know if this is advisable And what a fair price is.


Again, I highly recommend http://www.coupeking.com/
 
Unless you're sold on the idea of a new engine why not pull the head and check to see if it's just cracked (easily replaceable) or just the head gasket (even more easily replaceable)?
 
Makes sense

Steve, that makes sense to me but for some odd reason my mechanic is just not comfortable with this. I'm going to forward your email to him to see.
 
So which route did you go? Did you remove the center resonator and go with a magnaflow? If so, which one? Can you post a video of the new setup and throaty growl?
 
Stevehose said:
Unless you're sold on the idea of a new engine why not pull the head and check to see if it's just cracked (easily replaceable) or just the head gasket (even more easily replaceable)?
Click to expand...

i was thinking exactly the same thing ... especially if its a numbers matching engine. you could get a head built by a reputable group ... sfdon, korman, etc. and even put a good cam in it w/ a good valve train / ports and gain some performance.
 
Hmmm....I am not a mechanic and I managed to research and replace the head gasket myself....not sure why this is a problem for him to get his head around. Maybe he could refer to another mechanic who can?

scottevest said:
Steve, that makes sense to me but for some odd reason my mechanic is just not comfortable with this. I'm going to forward your email to him to see.
Click to expand...
 
chance is there is a crack that opens up when the engine is warm that pushes coolant (under pressure) into the exhaust or into the combustion chamber - which doesn't burn and is pushed out the exhaust.

possibly more than just a head gasket ... but could be just the gasket. if you took the head off, you would find out if there's a break in the gasket.
 
My guess would be head gasket based on the amount of coolant he's lost remembering past posts. On my first coupe I had the cracked head syndrome which youu describe (but mine blew steam until it sealed as engine heated) and overall coolant loss wan't very drastic. But who knows...

rsporsche said:
chance is there is a crack that opens up when the engine is warm that pushes coolant (under pressure) into the exhaust or into the combustion chamber - which doesn't burn and is pushed out the exhaust.

possibly more than just a head gasket ... but could be just the gasket. if you took the head off, you would find out if there's a break in the gasket.
Click to expand...
 
could well be Steve. i'm thinking the opposite of getting oil into your coolant reservoir. but i guess that would also gets steam into your oil - foamy at the dipstick. i guess it all depends on where the crack is formed (from what particular event). but the easiest thing to do is to pull the head and see - no blown gasket will tell you there's a deeper problem. all in all, much cheaper than finding an engine, shipping it and then paying a mechanic to put it in.
 
Rings and Oil

My mechanic just indicated he thought the rings might need to be replaced too, and thus it makes sense to just get a rebuilt engine. Not sure though.

To be clear, no soapy stuff in oil at all, and with long trips no loss of coolant. Seems to be intermittent.

rsporsche said:
could well be Steve. i'm thinking the opposite of getting oil into your coolant reservoir. but i guess that would also gets steam into your oil - foamy at the dipstick. i guess it all depends on where the crack is formed (from what particular event). but the easiest thing to do is to pull the head and see - no blown gasket will tell you there's a deeper problem. all in all, much cheaper than finding an engine, shipping it and then paying a mechanic to put it in.
Click to expand...
 
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