Struggling to understand a concept

My car is an Odd Fired V-6. Interval is 90-150-90-150 and so on...

Im trying to understand how an engine that vibrates at Idle and very low RPM smooths out at significantly higher RPMS. Id think any vibration at low RPM would become worse at higher RPM.

Ive scoured the internet trying to find some sort of physics or engineering that may explain away this, but Im coming up short.

The car is a Giulia Quadrifoglio

Thanks All.

What you are experiencing is the difference in amplitude vs. frequency for a given mass vibration. Here is a webpage description (that may be confusing, or just might have the references that make sense to you) of the relationship between frequency and amplitude:

https://www.vedantu.com/physics/relation-between-amplitude-and-frequency

It ends with this conclusion:

Does Amplitude affect Frequency?

The relationship between the wave's amplitude and frequency is such that it is inversely proportional to the frequency. The amplitude decreases as the frequency increases. The amplitude increases as the frequency decreases.

Yes! Excellent, I think this is exactly what I needed. Thanks David.

A big part of it is down to the human ability to recognise the frequency variation. At low rpm there is a relatively long period between each firing impulse and it can be noticed easily, but at higher rpm they will merge together.

The modern era of 1.6 litre turbo' cars have the same 90 degree configuration as your engine and, AFAIR*, run a common pin with the same firing split as you.A their operating rpm, darned if I can tell the difference?

*Can't swear to that, or that some don't have a partial split, just don't recall any.

Thanks for the Input Gord.

I think they made the engine in this way to have essentially 2 Inline 3's joined at the hip so they could deactivate an entire bank of cylinders for fuel efficiency. The car is fantastic and makes incredible power.

Would the crank be stronger torsionally than its split pin cousins or the fact that most cranks now being forged render it not that important?

GM made the 231 that way as it was easier to produce on the V8 tooling they had, there was NO sound engineering reason for it.

I don't know why that engine was made that way, but three possible reasons are the wider split angle would allow a lower bonnet line, it would lower the engine's CoG a little (also a factor in F1), and/or it would open up the area between the cylinders and head where other items could be fitted - such as a starter, alternator, variable intake mechanism, running the exhaust through the top side of the heads, etc.