1974 Dart 440 tuning help

roccodart440 said

What RPM's would you be seeing these increased numbers? What RPM are you starting these pulls at? Obviously the numbers you are seeing improved are under the curve, since timing would be all in by peak HP RPM, maybe not at peak TQ RPM.

Usually on a dyno I start my pulls between 2500 and 3000 and end them 250-500 past peak HP. I'm curious wat you are doing

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I start at about the same as you do, but when testing for timing I don't usually make a pull when doing it.

When sorting out timing curves I start at 2500 (maybe a skosh lower depending on what it is) and load the engine to different vacuum and throttle positions and let that tell me what the timing needs to be.

I have a 3 stage retard at the desk so i get the engine at say 2500 and start loading it down until I get the engine stable and then I add or remove timing until it makes the most vacuum.

Then I move up 500 RPM and do it again. Once you get to max RPM you can see what the curve needs to be at about any RPM and load.

The trick is getting the distributor to match what the engine wants.