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:The Z32 was designed with a cross flow intake manifold which is quite different from the other cars we're used to seeing FMICs on. What this means is that the left turbo feeds the right side of the engine and the right turbo feeds the left side of the engine. The reason for this is that when the exhaust exits one side it then pushes the turbo that is feeding the opposite side since it has the intake valve open to fill the cylinder for the next compression stroke. There's a reason they used Cray supercomputers to design this car, even back in the late 80s. Nearly every FMIC is reversing the way the intake manifold was designed and makes it no longer a cross flow manifold. I don't buy this theory at all. We are dealing with compressible flow here. I have a problem with this statement: The reason for this is that when the exhaust exits one side it then pushes the turbo that is feeding the opposite side since it has the intake valve open to fill the cylinder for the next compression stroke. This makes it sound as if the exhaust valve opening on one side of the engine drives that turbo and creates a pressure pulse to coincide with the intake valve opening on the opposite bank (I believe it was Greg that said something to this effect). It would be impossible to time the exhaust event on one bank to have ANY effect on the opposite bank because there is so much volume in the intake tract, MANY feet of piping, and the restriction of the IC's themselves that will easily dampen any pressure pulses if they were to exist. Due to the inertia of the turbo itself and the fact that the exhaust pulses at high engine rpm occur so rapidly, the exhaust will be felt by the turbo as a steady flow to the turbine (much like a pulse width modulated circuit) rather than individual pulses. Because of this, I have my doubts that any measureable pulses would be found at at the compressor outlet, let alone several feet away at the intake valve. :Now, talk to anyone on the "FMICs are worth it on Z32s" camp and they will either A) gloss right over this FACT I don't believe that to be FACT...that is pure speculation IMHO. However, I do believe side mounts are superior, due to better pressure drop across the core vs the long narrow cores of most FMIC's.
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14:31:40 01/28/05
