[SysCrusher]

My bad, removing that restriction in a typical 3/8" system would not bring it anywhere close to a system using 1/2" barbs with 7/16" tubing. I havn't got a decent calc to use to get it perfect and worth qouting here.

What I came up with so correct me if anyone likes to. This is not counting the block's or rads, Just the tubing, hose bards and or quick connects at 3lpm.

The typical 1/2 system with 4ft of tubing has a pressure loss of .0031 bar.
Replace the barbs with quick connects and it's 0.0013 bar.
With 7/16 tubing it's .00435 bar.

Your not losing much using the 7/16" tubing.

The typical 3/8" system with 4ft of tubing has a pressure loss of .01715 bar.
Without the hose barbs and replaced with quick connects it's .0147 bar.

So there's the difference that I came up with. I havn't done anything with bigger pumps, say around 6lpm yet or replacing the hose barbs in place of quick connects in the 1/2" system. With a 1/4" system, it's pretty dramatic.