67-LS1

I have a question about exhaust noise. Does the placement of the muffler in the system change the tone?
In other words, if you place the muffler near the engine and then run 3" pipe to the rear bumper, will this sound different then if the mufflers were placed just forward of the rear axle.
Or if a chassis allowed it, would it change if the muffler was the last component prior to the rear bumper.
I am interested in the exhaust noise out the tail pipe, not so much the resonance inside the car.
Thanks,
Dennis

gofastwclass

iTrader: (2)

Interesting question.
I've wondered the same, but never took the time to research experiment with it. I'm sure there would be some difference but would it be discernible to humans? In my experience tubing diameter, muffler style and location are often so heavily based on chassis design that there isn't much room for alternate options.

In theory (at least in my head) the muffler would have a optimal location based on tubing diameter and velocity of the pressure waves based on engine size and desired RPM. Having said that, the optimal location may be a range that is fairly flexible and thus minor variations might not very noticeable to human hearing. Case in point, Helmholtz chambers and their ability to reduce or eliminate drone in automotive exhaust systems. Two or three decimal point accuracy isn't nearly as important since getting the chamber length close typically does the trick.

There are several vehicles with rear mufflers and are somewhere near the mid to rear of the car. Interestingly enough now that I think of it I don't know of many that have mufflers right off the engine that aren't mid or rear engine vehicles.

jlcustomz

I think the biggest difference in sound as far as location is how much pipe length you have AFTER the mufflers . Shorter pipe can sound more choppy, longer tailpipes a little more mellow. OEM & aftermarket mufflers set at rear bumper generally are a different design than your universal types. For something like a 67 Camaro with an ls, you generally fit the mufflers in the average location that they fit in. Muffler choice, pipe size,even pipe thickness & type( stainless or not), & x or h crossover, tailpipe length, & even actual tailpipes & exit location are your usual variables.

bczee

iTrader: (12)

In the old days. I was told to put the muffler as far back to get the noise level down. Not really sure how true it was. but it seemed true from the seat dyno.

BC

67-LS1

I'm curious because I am putting an LFX V6 in my 1966 Chevelle and want the engine to sound "larger" than it is.
I notice that on my friends WRX that the engine sounds very deep and mellow. But when you hear late model Camaros with V6's they sound so "small" or "tinny/raspy". I have never heard one sound like a V8.
I know this is mostly due to the 6 cyl vs 8 cyl firing but was hoping to figure a way using mufflers/resonators/pipe size and length/?? to try to make it sound larger.
This will be my commute car so it will need to be relatively quiet but have a mellow tone.
Dennis

BudRacing

iTrader: (3)

I believe the difference in the WRX and the v6's in camaros is more about the engine design differences than mufflers or placement. Large piston bores have deeper tones. Likewise, a BBC sounds deeper than a SBC in identical setups.

67-LS1

Would running a single system vs duals help? I am thinking more pulses per rev with a single system and the engine is only 217 CI so back pressure should not be an issue with a 3" system. Maybe sound more like half of a V12?
My goal with this build is 35 mpg so the weight savings of a single system could help I too.
I get the "smoothing affect" of a turbo. I hear that on my Mini Cooper. It has a Cat right after the turbo then a muffler at the very end near the rear bumper and sounds a deeper tone than a newV6 Camaro.

ls1nova71

iTrader: (4)

Do the new Camaros even get that high if mileage? Seems like it may be a touch high of a goal in a relatively heavy and not as aerodynamic car. Good luck with it though, seems like it would be a cool swap and I for one have never seen anybody swap the newer V6 into anything.

67-LS1

The new Camaro has an EPA rating of 30 mpg and weighs about 3,900 lbs.
My car with the 283/Powerglide weighed 3,172 lbs right before I started disassembly. It had about a 1/4 rank of fuel.
My goal is to be under 3000 lbs when done. The new engine/trans combo is 153 lbs lighter so with aluminum wheels, aluminum radiator and a switch to manual brakes, under 3000 lbs seems achievable.
I would think (hope) that 900 lbs of weight savings would be worth some mpg. Aerodynamics will definitely not be as good so we wil see.....

Exidous

iTrader: (11)

I think restriction plays the biggest role in how loud the exhaust is. I think you'll be happy with a single 3". I used it for a long time in my RX with the LS1 and it was quite tame. Most didn't even notice. Did it cost me some power sure but I didn't hate driving more than 20 min.

With a free flowing exhaust resonator, x-pipe and muffler location become much more important. I am now running dual 2.5" into a single 3.5 catback and am happy. The addition of cats keeps the noise down quite a bit. If you are going catless just put a resonator in their place.