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HOWTO: Flat shifting/fuel cut on gear shift in manuals

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Go to "Custom Operating System Configuration"

Select "TPS override for flat shifting" and select any other options you require in the Custom OS (such as dual maps, spark table resize, etc)


Now select "Enable Custom Operating System" from the dropdown menu to enable the custom OS. (2 extra credits required).

This will automatically set all scalars for launch control and flat shifting along with adding the new TPS enable condition.

Now set "TPS Threshold" to roughly 420 (experiment).


This will enable the car to flat shift on full throttle if the following  conditions are met.

RPM > auF2035 (Fuel cut RPM for launch)

Clutch has been depressed

TPS > auF100016 (420 is roughly 80% throttle).

This means you can drive the car around town normally above 2500 with no fuel cut, however if you use full throttle you will get a fuel cut.

OId Manual Method (no TPS activation setpoint and no Custom OS required)

First setup launch control as specified in the above thread.

Now to enable flat shifting we utilise the launch control whilst the car is moving. To do this we set the launch control rpm to something reasonably high but  is still above the lowest rpm you will be shifting at. Eg 3500 rpm should be a good point.

Next set auF11836 (Minimum vehicle speed (mph) for manual vehicles to limit launch rpm to a high number like 200mph. Note that this parameter is only available in the workshop version of the software.


Now when you shift gears and are above 3500 rpm there will be an aggressive fuel cylinder cut above 3500 rpm once the clutch switch is activated. This means you can hold the throttle flat during shifts.

It is recommended to bend the clutch switch bracket so that he clutch switch is not activated until the pedal is at least halfway pressed in. Otherwise there will be a lag between the clutch engaging and the injectors reactivating. If you are not running upgraded diff bushes and a diff hat you could quite quickly destroy the stock bushings.

Once you have the clutch switch adjusted you can play with the rpm setpoint so that you can still daily drive the car without a fuel cut occuring.

On the drag strip this will mean you retain close to full boost on gear shifts. Eg in testing (using a WOT box so not 100% the same system) we have seen a car running 20psi only drop to 16 psi on a gear shift. In contrast if you close the throttle you lose all boost, this will make a big difference on the drag strip.

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