I had asked about the M370 Plenum during the first part of my build and was told that these modified plenums were OK with NA motors but with Hi Boost FI motors they had a tendency to flex and warp under boost.
The reason given was that the modification to the plenums included cutting and removing some of the internal baffles and while allowing for a more direct airflow they also compromised the structural integrity of the design.
How true ??? I dunno - but I stuck with the OEM plenum at least for now.
The car isn't finished yet but is in the final stages ...
Hope to get it on the road and put some miles on it before it's time to put the winter cover on it !!!
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