Did you do both together , that is remove the mesh plates and fit the HPD at the same time?
If thats the case that would be a huge increase in air flow, and you compensated that with extra boost?
On that thinking removing the mesh and replacing the OE hoses should see some gains as well
http://www.ebay.com.au/itm/NISSAN-PA...00722191&rt=nc
If funds allowed this would save a lot of work and looks very well built