I'm planning on infusing some sandwich panels that will be 1 outer skin of 200gsm carbon 5mm perforated PVC core and 1 inner skin of 200gsm carbon. Will it negatively influence my infusion if I only put peelply on the inner skin (bag side) where I plan on doing secondary bonding? The whole thing would have a layer of P3 film and flow medium on top of it.

I don't think having a peel ply or not will make much or any difference to the infusion speed.

With just 200gm fibre on the mold side you need to be sure there are enough holes and/or grooves to let the mold side flow ok.

Is your core drilled or grooved in any way?

The core I'm getting is not perforated but I'll do it myself on my CNC. It seems like industry standard is 50mm centers which would add around 6gms/m2 it seems like bumping this up to 25mm centers would be a good idea as the 24gms/m2 seems like a small hit verse having wet out issues. I'll run a few test pieces later this week.

unless you are going to mill out non standard grooves, just buy the core pre-drilled. It's not worth the time on the CNC.

To some extent my core choice reflects what is easy to get in Portugal. Also, as I have the CNC machine it's not a big deal to have it drill holes.