HPT ON HOLDEN

When tuning on the dyno i see that you can get the rpm very low .when using a auto are you loocking the trans out so it does not kick back gears.

or if any one has any help answering this

thanks

With the later model 6 speed auto you can lock the transmission in a gear (I usually use 3rd) and it won't kick down. There will still be some torque convertor slip at low rpm so the displayed rpm on the dyno (which is calculated based on road speed and a ratio) will be inaccurate. For example the dyno might be showing 1750 rpm but the engine rpm is more likely to be something like 2000-2200. As the run progresses and the torque convertor locks up the rpm becomes accurate.

On the older 4l80 transmission it will kick down if you go to full throttle at very low rpm. I will again use 3rd gear but I start the run with around 75-80% throttle and smoothly open the throttle over the first 1000 rpm of the run. A bit of testing will find the point that the trans will kick down and you can learn to avoid this happening.