Because an engine dyno can hold an engine at any particular load and RPM, it allows Jeff to systematically go through the engine's entire operational range to optimize both A/F ratio and timing for any condition the engine will ever see. Once this is done, Jeff can then move on to accelerator enrichment settings. But in order to properly set the cold start and run parameters, the engine needs to return to stone cold again. If you can't leave your engine on the dyno that long, these items are easily tweaked in the car. We picked up about 20 hp on the top end with a max of 503 hp at 6200 rpm, and we lost about 15-20 hp down low but this is about what you might expect from switching from a dual to a single plane manifold.