I think its more than just a correction for altitude and temp. Its also a correction for engine tolerances and the different signal they create. Look at how Keihin jetting varies. The SC has what is essentially a feedback loop, so any differences in demand are a wash once corrected, and the initial metering rod adjustment made. This is why they can use just one metering rod for a wide range of applications. No need for an array of multi tapers, its all done by the variable fuel pressure in the bowl in relation to the vacuum signal at the rod/nozzle. You adjust the OVERALL mixture by the mechanical position of the rod, and its taken care of at different points in throttle position.
The only thing I can see being perceived as a limitation is that there is no way to intentionally tune a certain area alone slightly rich or lean, like is done in the case of mellowing out a 300. On the flip side, this is usually done as an alternative to needles/settings with less than linear characteristics, that we just happen to be bound to due to availability. This is a very different way to think about fuel delivery.
|