Designed not only for sound, but also also for performance. The 8-4-1 design was first tested using an engine simulator (EngMod4T).
By utilizing equal lengths and a single collector we get a uniform exhaust pulse resulting in the distinct sound of an even firing engine. With the collector getting an exhaust pulse every 90 degrees of firing, we also get continuous scavenging that is also amplified by the smaller collector volume.