|See Xtra Flatshift in our shop|
Tuesday, 24 July 2012
Xtra Flatshift is a pneumatic, closed loop system for controlling sequential gearboxes to provide clutchless up and down shifts. Additionally it provides a gear display and can be programmed to perform automatic upshifts with a different rpm set point for each gear Likewise, downshift rpm limits are separately programmed for each gear to guard against overreving the engine. Besides the pneumatic components, there is a small electronic module which fits entirely inside the XoomBox. All the I/O signals used to control the gearbox are then included in the datalogs created by the XoomBox and can be examined after a run using our XoomCentre software.
If you ever have the chance to drive a race car with a sequential gearbox, it only takes a couple of minutes to realise that the slowest part of the gear change is you! Upshifts without using the clutch aren't too difficult to get the hang of, but once you start trying to push the speed of the shift, most people find it's difficult to get hte timing of lifting the throttle, changing gear and reapplying the throttle just right. I f you don't lift enough, the dogs don't unlock and the gearbox doesn't shift, lift too far and too long and the car will go into engine braking, and again the dogs lock and the shift doesn't happen.
The obvious solution to this is to automate the process, so that's what we set out to do with the Xtra Flat Shift X10der for the XoomBox.
We chose to go for a pneumatic solution because pneumatic actuators are easily adjustable to provide a wide range of effort to suit any gearbox, and the progressive way in which the force arrives is good news for the lifetime of the gearbox.
There are a number of systems like this on the market and there is little doubt that the closed loop systems - ones which measure when the gearshift has completed as opposed to ones which simply time and hope - are the most successful.
For our system, the gear shift is activated by commonly available pneumatic actuators with magnets mounted internally on the piston. We then place magnetic sensors on the outside of the cylinder to detect when the piston has moved to the end of the stroke and the gearchange has completed. This approach is commonly used in a wide range of industrial applications where it has been found to be easy to install/setup and very reliable. Suitable actuators and matching sensors are available in a vast array of shapes and sizes, which means we can offer systems to suit almost any installation.
For upshifts, there is an output provided to tell an external ecu when to cut the engine, or, if you are using the XoomBox's traction control facility, the XoomBox itself can perform the engine cut. For downshifts, we employ another, much smaller, pneumatic actuator mounted typically at the throttle plate(s) to provide a momentary throttle blip to enable the downshift to take place.
All the gearshift parameters are entered using XoomCentre
Watch the video below to see Xtra Flatshift in action
This site was last updated 09/03/10