Residual Valve Question for the brake experts....

[DonohurJav]

Hi all,
Hoping to get an expert opinion on whether or not to use residual valves & what size if needed on my application.
I'm using Wilwoods new Aero 6 & aero4 calipers with piston areas of 4.04 sq.in & 1.98 sq.in respectively. I'm also using CNC brakes' dual master cylinders with balance bar in a 3/4 & 7/8 sizes as recommended by wilwood. I've studied a couple of brake engineering books as well as most of the posts from Tobin and OG, Ron Sutton etc. and still can't quite grasp when and when not to use residual valves. The plan for this car is 80-90 % street and some autocross with the occasional track day mixed in. For the street I realize I wont have a problem, but for autoX and the track days I know that pad knock-back will be a problem as I am not running a full floater rear. I guess my real question is, will running residual valves keep some pressure on the pistons and help with knock-back? My master is going to be on the firewall in the stock location ie. above the calipers, so I wasn't planning on running any residual valves. I am currently plumbing the system from scratch with the usual 3/16 with braided soft line and would like to do it only once, LOL! If residual valves are recommended for knock-back (or other reasons) , what sizes? 2, 5, or 10lb? Thanks in advance for any and all help! I love this site!

Sean