Re: Wideband Holley 4150 tuning
Good morning and happy Memorial Day! A little update. Cruising around town with no aggressive throttle, my AFR’s are running between about 11.3 and 12.8. Cruise on the highway, 5th gear (0.64) @70 mph and 2000 rpm, AFR’s are 12.8 - 13.2. Not sure that turning in the idle mixture screws is indicated since I'm still operating on the idle circuit at cruise, but I have a feeling that if I do, the engine is at the cusp of the curb idle speed and or vacuum dropping. If I depress the pedal fully to the floor, the motor has a tendency to heavily bog to the point it likely falls on its face. As a side note, the carburetor is brand new. I switched the stock primary #65 jets for #68s. I haven't changed the secondary jets and I believe they are also #68s. Also, I notice the fuel pressure upon cold start in about 5 psi, but by the time the engine has come up to operating temp, it has fallen to about 3.5 psi. Raising the engine rpm appears to have little or no effect on the fuel pressure. I don’t have another gauge to verify the accuracy of the one connected and its my understanding that a minimum of 5 psi is needed to adequately supply the carb especially under load. Is a drop in fuel pressure as the engine comes up to temp normal? What carb adjustments should I make at this point? I have been reading Mike. That link has alot of great information.
69’ Camaro convt. Metallic grey, Blueprint Engines roller 383 stroker 445hp/465tq. Edelbrock Air Gap intake. Holley Terminator EFI. Hooker stainless headers. Tremec TKO-600 5 speed, 3.55 posi rear, Vintage Air, March Performance, TMI Interiors