Fine Tuning a 360 Magnum with a Brawler "Double Pumper"

92b said

When I did this test on the dyno the main circuit started at the same rpm no matter what size bleed I put in it. I even took the bleed clear out and it didn't change when the booster started flowing. It was an easy test to do. Try it sometime on your dyno and report back the results. My test may have been a fluke

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@92b I don't want to revive another thread for your sidebar there.
A. Outstanding experiment.
B. We can see that of the variables changed, the biggest impact effecting the booster start rpm is the load. That makes perfect sense because the main system is driven by air flow.
C. In my opinion your experiment fits well with the published graphs from the old books Tuner and Shrinker shared and posted about. IF the emulsion holes are ballpark correct, then the primary job of the main air bleed is AFR correction at high rpms (higher MAF). Main circuit initiation is, or should be, impacted by the upper e-hole(s) and to some extent a 'kill-bleed'.

So my prefered approach, is idle - off idle, then some degree of drivability, followed by a full load test with WBO2. That could be drag strip, or IMO better, chassis dyno. Chassis dyno has the advantage of better controlling the variables and being able to run 3rd (or 4th gear) through the power peak. Other than drag race focused cars(trucks), we're through the 1/4 mile well below peak HP. When looking for AFR drifting richer or leaner I want to see max load at max rpm. Once MAB is there, I'd leave it unless a majpor change is made to the jetting and/or PVCR. I know Mark Whitner and others prefer to stay in sequence building the tuning of each circuit from idle up but I htink for a lot of us its often more practical to jump ahead to some full throttle tests and at least see if the AFR is staying flat.