Hi
Is it possible to tune with a vacuum gauge? For example, I have a vacuum gauge hooked up and can see a difference when driving at 70 kmh in forth or fifth gear - 1700 or 1000 RPM respectively.
The primary rods are controlled by vacuum, does that mean I should always go for max vacuum, no matter the RPMs? Or does higher RPMs mean more air moved, and thus more fuel consumed? I'm at a loss.
Engine info:
Engine: Olds 380 stroker 9.5:1, roller cam, Ebrock performer RPM intake, stock 7a heads with 2" intake valves and a bowl blend port job. HEI off a 403 Olds connected to ported vacuum, set to 19 btdc initial timing.
Carb: 17057253 rebuilt for the old engine, a stock '71 Olds 350 8.5:1. Currently has Third Recipe idle system modifications. Slight stumble off idle when cold.
