Power Commander Autotune MAP Switching

[Kraythorne]

Does anyone know if it is possible to connect the MAP sensor to the temp input of the PC5 and configure the readings in the same way as the temp settings to prevent autotune trimming when the throttle is closed?

 

If this is possible then I may give it ago and just put a manual autotune switch on the handle bars and turn it on manually when the bike it up to temp.

[MadScientist]

You can use both features - enable autotune once the bike hits about 160 and use the manual switch inputs to disable autotune under closed throttle.  I would say the easiest way to disable autotune under closed throttle is with a vacuum switch.  Here's how I did it:

First I used a vacuum gauge temporarily mounted  onto my dash, tapped into the vacuum lines off the throttle bodies, to determine the vacuum under overrun conditions, I've long since forgotten the actual value.  You have to ride the bike on the road to determine this, it can't be done in the garage.

 

Second, use a handheld vacuum pump to set the switch point on an adjustable vacuum switch to just slightly below the lowest vacuum reading from step 1.  Most adjustable vacuum switches have 3 terminals - one is common (COM) and the others are either normally open (NO) or normally closed (NC).  You want to use the NC side so that when vacuum exceeds our setpoint, the contacts are open.  This will require a test light and a power source; or multimeter.  Just to be clear your are testing continuity between the COM and NC terminals, we are setting the vacuum at which point continuity is broken.

 

Using the same point that you tapped into vacuum in step 1, attach a vacuum line from that point to the vacuum switch.  Wires should connect from the power commander to the COM and NC terminals.  Now when your throttle is closed under overrun, the vacuum increase causes the switch to open and autotune to cease.

 

Just to note you need a vacuum switch with a setpoint range from approximately 10-25 in Hg.

 

This could be done with a MAP/vacuum sensor but you would need to know the operating characteristics of the sensor then send that output into a voltage comparator.  Output from the comparator feeds a relay that does the switching.  Way more complicated and subject to voltage fluctuations of the electrical system of the bike.

[Kraythorne]

So something like the following items ;

 

Adjustable pressure switch

 

Hand held vacuum pump

 

Thinking of using the vacuum gauge from the pump for the initial reading for consistency.

[Kraythorne]

By the way, can you remember what the vacuum hose ID is, so I can purchase some extra hose and a T connector?

[MadScientist]

The switch I have looks very much like this:

https://www.amazon.com/Superior-Universal-Adjustable-Vacuum-Switch/dp/B00BZODN9A/ref=sr_1_1?ie=UTF8&qid=1525878540&sr=8-1&keywords=adjustable+vacuum+switch

 

Might be the same, but has been a few years now.  People use them to set lockup of automotive automatic transmissions.

 

Vacuum pump is perfect.  I actually used the gauge on the vacuum pump to measure engine vacuum on overrun, just taped the whole thing to the dashboard.

 

Sorry, I don't know what the original ID is, but the end measures about .16" so I would guess it was 1/8.  Could be metric too, so like 4mm.  End was a little stretched out from being over a fitting.