Quote:
Originally Posted by sparoz
Imagine you are spinning the spool with your left hand and right hand. You do it once with your left and twice with your right - it works (I know it is over simplistic).
The way I see it is that having two pulse on one scroll is definitely better that three on one scroll. If you look at firing sequence 1 2 3 4 5 6 (not cylinders), where Turbo A connects to 1 3 5 and Turbo B connects to 2 4 6; Scroll A1 connects to 1, 5, and A2 connects to 3, Scroll B1 connects to 2, 6 and B2 connects to 4. The volume and pulses feed to the charger is the same - 3 by volume of air, and they would be evenly spaced out regardless of the uneven scrolls as the two scrolls feeds to one charger. The continuous feeding of the charger should create the back pressure require on the two scrolls, while the separation of the two cylinders on one scroll and the isolation of the one cylinder on the other should reduce interference. Timing, as far as I know is done by the size and length of the runners in the manifold - CCM is the latest BMW technology. As the key to this set up is in the manifold, I believe BMW, who is renowned for this would be able to come up with a solution.
I am no engineer but that's why I can't see why it is a problem, and of course due to my limited knowledge and understanding. However, I think I am guilty of getting this OT. Let's go back to the N54.
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yes, but if you spin once with your left and twice with your right, you can run into interference on the right side. for instance lets say you spin the wheel at a constant speed. with the left hand, you spin it once and the whole spin is completed. with the right hand however, as soon as you finish the first spin, you must spin it again. that's where interference comes into play. the faster you spin (more rpm) the first spin with your right hand may not have finished when you begin the second spin. this would then defeat the whole purpose of twin scroll to begin with, because there is interference from 2 pulses into 1 scroll too close together.
if you look at your example, the spacing between 1 and 5 is fine, but the spacing between 5 and 1 isnt. they're too close together.
is 2 twin scroll possible? yes of course. is it worth it? i dont think so...