MoTeC Global Forum

On our Subaru Impreza race car, we have DBW throttle and sequential gearbox. We set up the downshift blip, it works, however the throttle opens 20% during downshifts although we set the DOWNSHIFT DBW POSTION up to 50%.

Any sugestions?

Also, what is a good starting point for DOWNSHIFT DBW duration?

Thanks,
Adonis
www.am-autoexe.com

DBW opening position is limited when TPD = 0

NOTE that TPR will clamped to 2 x TPD + 20 even if the table requests
more. For example at 20% TPD, TPR cannot exceed 60%.

This is a safety feature to ensure that the driver still has reasonable
control of the throttle even if the table calls for an inappropriate
value, perhaps due to a fault sensor connected to the Y axis of the table.

An exception to this rule is when Overrun Boost Enhancement is active
where TPR can be increased to TPD + 50%.

I have used 100 ms- 150 ms on a bike gearbox with 20% Blip position.

Also worth looking at the Down shift RPM limit in the Gear detection setup, this works well with blip to match RPM.

Thanks! So how can I increase the throttle oppening on downshifts? TPD on downshifts is always 0 i suppose. Or if I set up the Down shift RPM limit correctly, will it match the revs and no need for more DBW pisition?

Which other parameters do I have to set up in Gear Shift - Gear Down Shift table? No paddles are used.

How can I set up the Downshift cut duration so the two are sychronised? i.e Ignition Cut then blip then ignition re-activate.

Any advice on how far can I go on the upshift ingition cut delay to make as fast upshifts as possible?

Thanks for everything, this is a new thing for me and I'm trying to set up the car correctly to make full use of the DBW

The downshift blip table is not limited like IDP said, I blip mine to about 35-40%. The limitation is only for the translation table, not any of the functions using the DBW (Anti Lag, Blip, etc).

It could be that you are not allowing it to blip for long enough, I blip for 175msecs. Also, how fast are you logging the channels, if the log rate is slow it may look wrong.

How fast you can go with the cut on upshifts depends on many things, the devil is in the detail. You need to log everything to do with the shift nice and fast to get the best idea. RPM, Ignition Cut, Barrel Position, Up Shift Cut Request all at at least 100Hz.

Might need to send me an email with some logging to mark.mccoy@motec.com.au. What gearbox is it?

Thanks Mark,

The blip duration is indeed short, only 40ms, I will try to increase this next time I hit the track.

The gearbox is KAPS 6 speed sequential http://am-autoexe.com/product-details/331

I'll send you an email with my latest logging and programm.

Thanks again,
Adonis