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Old 10-08-2006, 12:32 AM
ChevyHighPerformance ChevyHighPerformance is offline
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Join Date: Jul 2005
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Default Re: Any feel like having a tuning discussion?

Just an update. With the new increase in low end torque, I modified the auto tranny shift speed table. This table shows at what MPH and throttle position you want the tranny to upshift or downshift for each gear. I lowered the MPH at which the tranny up shifts and I moved out where the tranny down shifts - I added more hysteresis. So when you are doing 60 MPH and you press on the throttle slightly the tranny doesn't down shift to 3rd right away. I get into 4th gear much quicker now and the acceleration in 4th is fine for small-medium grades. If I need more acceleration, I just blip the throttle more and the tranny will downshift. The stock shift tables can cause you to downshift (4th to 3rd) if you increase the throttle by as little as ~12%.

For low throttle positions I upshift quicker for better (hopefully) MPG. When you need the acceleration the new shift table doesn't hold you back.
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