Umm...that's not how turbos work, at least not on your setup. You aren't running staged turbos. You are running two parallel turbos, 1 on each bank of the V8. If you are making 20 psi in the intake manifold, that means each turbo is making 20 psi - NOT 10 psi. If you stage the turbos - meaning one feeds the next turbo, then that turbo feeds the intake, THEN you can have two 10 psi turbos making a total 20 psi.
But in your case, both your turbos are pushing 20 psi. And how are you measuring psi? One of the huge downfalls of remote mount turbos and why most folks don't run them is because they are too far from the heat. Heat = Happy, Spooly Turbo. They end up being too laggy unless you are running smaller turbos. If you really are getting 14 psi - then I'd be surprised. I think you said the car wasn't intercooled. No offense, but no way are you running 14 psi with no intercooler, your IAT's have got to be through the roof. Are you running meth or something? 5, maybe 6 psi (or perhaps 7 psi, maybe that's where you got the 14 psi from) you might be able to get away without using an intercooler, if your cold pipes really are that long, then it's possible they are losing some heat on the way to the intake. I'm not so sure about your boost pressure.
Honestly, you'd make more power if you hung the turbos up front in the engine bay. You are losing tons of heat on the way to the turbos.