We did testing of the filters a few years ago and found that the area of the Apexi filter was too small and combined with the fact it does not have the velocity stack JWT uses caused a drop in power and much richer condition. The average gain with the jwt over the Apexi was about 12 RWHP on stock turbo cars with dual pops. The tests were done with adjusting the A/F correctly for both filters independently. The Apexi always has a richer mixture of the two when swapping back and forth showing it is much more restrictive.
