Originally Posted by smdandb2
One thing that is getting disputed is the stock IC efficiency. Guess what? BMW has a map for this in MSD80/81. They tested it, and mapped it. Looking at multiple points (such as what Nick did) you can generate some equations to figure it out thru various PRs. Maybe BMW was off, but the fact remains there is SOME pressure loss.
But, I just stuck with 2psi drop thru the WHOLE system. Feel free to check my math and do a 3psi drop, its hilarious!
It's math, not rocket science.
One thing you have to remember is that the pressure drop from turbo to intake manifold will NEVER be a constant, but will ALWAYS rise exponentially as a function of airflow. This isn't my opinion, but plain old physics (ie, fact) that cannot be disputed or ignored. I've flowtested many intercoolers and pipes in the design of my BMW turbo kits, and know how to predict, or rather calculate, the pressure drop of a system on the car as a result of the flowbench data.