Tune by ear

I have very long and dexterious ears… (sorry). With all the advancements in engineering in the automotive industry, why does a Ford (and other makes) sound the same as it did 60 years ago given they both have performance mufflers?

They dont

Sixty years ago, engines of different makes of automobiles did sound different. The Ford flathead V-8 had a distinctive sound as did the Chevrolet stovebolt six or the Buick valve in head straight eight. My brother and I could identify these engines whether they had stock mufflers or performance mufflers. I used to ride back and forth to college on a local bus line. The buses were Flxible (yes, the spelling is correct) bodies on GM chassis. The engines had a familiar sound. I guessed that these were the straight 8 Buick engines in the buses. I said something once to the driver at the end of the run. He took me to the rear of the bus, opened the engine compartment and it was a straight 8 Buick engine. The exhaust was completely open–no muffler at all.
The VW aircooled Beetles had a distinctive sound. The engine that comes close to that sound today is the opposed 4 in the Subaru.
I think that the differences in sounds of engines has to do with the number of cylinders and the configuration of the engine. One distinctive sounding engine was that of the 2 cylinder John Deere tractors of the 1940s and 1950s. To this old country boy, no engine sound equals that of these old John Deere tractors.

I might also add that the smaller outboard boat motors 60 years ago had distinctive sounds depending on the manufacturer. The Mercury outboard engines had a definite whine as the boat pulled away from the pier–definitely different than the sound of the Johnson-Evinrude twins.

There are a lot of contributors to how an engine sounds, some internal such as the crankshaft timing (a 90 degree crank fires diferently than a 180 degree “flat plane” crank, sending the pulses down the pipe differently), the number of cylinders, the exhaust, and even the intake. Even the induction system design makes a difference. Engineers design the systems to get the sound they want. Miata actually “tuned” the exhaust system to sound like the old MGBs. For luxury cars, sound is eliminated as much as possible. For other cars like my tC, the sound is reduced as much as possible without compromising the cost. An angine needs an intake snorkle, so they designed it to reduce sound. Look under hoods of new cars and you’ll see variously shaped “baffles” on the intakes designed to buffer sound.

I recently made some changes to my own intake and it changed the sound. I like the new sound. It’s throatier.