I kinda agree with Dave. Shunts didn't imprve performace much if at all on my builds. I have two PSO cars built exactly the same with the exception one has shunts. They are pretty much the same in performance. An old racer one told me shunts are ony good to hold the pick up shoes to the chassis so they don't go flying off into the abiss with the shoe springs during a crash.
Another perspective here is consistency in the electrical path. Without shunts the electrical path is through the pick up hinge and spring which can "potentially" change as the car goes down the track or as it gets dirty. The shunt makes a positive connection that doesn't change. It just removes that as a concern. We are dealing with .0001 timing increments after all. Sometimes that is literally the difference in a race. I install shunts every time they are allowed. Just my two cents.....
A good example of what Jeff is talking about is Jag’s DR1 chassis’’s. They seem to have a poor ( or at least inconsistent ) connection between the shoes and brush holder. I can’t get those things to run descent without shunts. Those cars only get run in classes that permits shunts.
Actively enjoying my second, or is it third childhood?