To me, the Civetta Bolide sounds so good and it also revs pretty high. The sbr4 is a bit too rough but it's also good
I love the sound of the I4 mated to the Ibishu Miramar. Too crashy for most modern cars, it sounds absolutely spot on for the Miramar.
I think the inline-four sound in BeamNG lacks that distinctive "growl" that 4 cylinders tend to produce. Here's a good example: Another thing that makes that sound feel so "correct" in the miramar would be that it sounds very smooth. Modern engines are fuel injected, and the fuel injectors produce a "ticking" noise when idling (you can hear this in pretty much any engine with fuel injection). Older cars like the Miramar are carbureted, so the only sound you hear is the intake and exhaust Having said that, I think the Miramar's engines should sound lower pitched. For comparison, here's a mostly stock 1.2L engine from roughly the same era as the Miramar sounding much better: (this is running roughly the same intake system as the miramar's DOHC engines)
SBR4: Absolutely demonic-sounding, and if it had an exhaust sound that raised its pitch even higher, its awesomeness at redline would probably blow my little Dell laptop's dual-core i3 CPU to the moon. Bolide: Yeah, sure, it doesn't have a proper sound to fit its engine type, but good grief, does it sound nice. It sounds almost primal, to be honest, and it's a great encouragement to go as fast as possible in a race.