CM848 switch on the fly

[whiplash]

Anyone know if the switch on the fly works with the CM848 2005stock.hpt for hptuners? i see the parameter in the tune but im trying to find a switch to utilize it and cant seem to find the physical switch.

[RGHTBrainDesign]

Where are you seeing a switch in the tune?

The 0-4 Tables are all supposed to be conditions based on elevation.

That being said, let's figure it out!

I have a Banks Economind that I use to blend in with a basemap of what I have tuned in the truck. Won't want to go over Level 3 Towing or Level 4 Street (stacking tunes), but its switch on the fly that way.

What this has enabled me to do is ramp CP3 rate higher or keep base max timing around 21* so if I end up needing a bit more umph, it's there.

To my understanding, the Banks Economind does CP3 Pressure + Main Pulsewidth Table and STOCK Timing. Banks Six Gun does TIMING, CP3 Pressure, and Main Pulsewidth Table. So if you are stacking and building your own timing maps, I'd think Economind is safer.

This lands you a shift on the fly switch and a great way to monitor all your sensors to know how you're doing.

[Jim P 2.0]

There is no SOTF available for your model year. What you can do is rescale tables and a rotary switch to control the signal going to the ecm from the baro sensor to mimic altitude changes to switch between operating modes to in a sense have SOTF. Pretty much the same that is done for the CCV SOTF on the 6.7L's. Not quite the best way to do things, a hard coded SOTF would be best as it would not be messing with variables used by air density, etc in the logic of the engine management of the calibrations. Stacking is super old school from the before the days of custom tuning.

[B00STJUNKY]

There is no SOTF available for your model year. What you can do is rescale tables and a rotary switch to control the signal going to the ecm from the baro sensor to mimic altitude changes to switch between operating modes to in a sense have SOTF. Pretty much the same that is done for the CCV SOTF on the 6.7L's. Not quite the best way to do things, a hard coded SOTF would be best as it would not be messing with variables used by air density, etc in the logic of the engine management of the calibrations. Stacking is super old school from the before the days of custom tuning.

Can confirm that this is a way that it can currently be implemented. But, as Jim suggested, it's not entirely ideal. One thing I recently discovered as I was trying to implement different pressure curves for the injection pump that would work in tandem with timing and commanded mm3 tables tailored to the respective pressure targets, it seems that the rail pressure tables don't follow when switching between the different air density setpoints. I need to do further testing to verify whether the pressure tables simply don't switch at all (which is what it seemed like I was seeing), or if they're potentially mislabeled, and I was just getting unexpected pressure curves for the respective setpoints I was expecting based on switching between the different density tables as they're currently labeled.

The rotary switch was something I built on my own, doing some work to determine the necessary resistance to equal a specific voltage that would then be interpreted as a barometer pressure reading. Then, the table that defines what measured/calculated air density correlates to the available density tables for the various parameters was reworked to allow for a certain amount of range and/or error within the calculations I made for those target voltage (density) setpoints.

The end product isn't quite as refined as something I'd be comfortable with marketing and producing for end users. But it has been installed in the truck for a few years, now, and has been working as intended to switch between (most of) the various density tables in the calibration.

[Noah]

Can confirm that this is a way that it can currently be implemented. But, as Jim suggested, it's not entirely ideal. One thing I recently discovered as I was trying to implement different pressure curves for the injection pump that would work in tandem with timing and commanded mm3 tables tailored to the respective pressure targets, it seems that the rail pressure tables don't follow when switching between the different air density setpoints. I need to do further testing to verify whether the pressure tables simply don't switch at all (which is what it seemed like I was seeing), or if they're potentially mislabeled, and I was just getting unexpected pressure curves for the respective setpoints I was expecting based on switching between the different density tables as they're currently labeled.

The rotary switch was something I built on my own, doing some work to determine the necessary resistance to equal a specific voltage that would then be interpreted as a barometer pressure reading. Then, the table that defines what measured/calculated air density correlates to the available density tables for the various parameters was reworked to allow for a certain amount of range and/or error within the calculations I made for those target voltage (density) setpoints.

The end product isn't quite as refined as something I'd be comfortable with marketing and producing for end users. But it has been installed in the truck for a few years, now, and has been working as intended to switch between (most of) the various density tables in the calibration.

Do you have details on the resistors you used and if you hooked into the baro sensor? I have wanted to try messing with this for a while. Feel free to message me some details on how you set this up. Thanks

[Jim P 2.0]

It has to alter the voltage back to the ecm from the baro sensor, no choice on that one. If it doesn’t you are not altering anything to tell the ecm to switch tables. Don’t need resistors or know resistor values. Plenty of outfits make a 5 position rotary switch that you will need to use as the baro sensor. There will be tables and parameters you will need to alter to not cause errors and to make it properly switch between tables based on the voltage the ecm sees from the switch

[B00STJUNKY]

It has to alter the voltage back to the ecm from the baro sensor, no choice on that one. If it doesn?t you are not altering anything to tell the ecm to switch tables. Don?t need resistors or know resistor values. Plenty of outfits make a 5 position rotary switch that you will need to use as the baro sensor. There will be tables and parameters you will need to alter to not cause errors and to make it properly switch between tables based on the voltage the ecm sees from the switch

Yeah, I wasn't, and am still not entirely sure what was or is commonly available on the market in terms of rotary switches, and their respective resistance settings per switch position. It makes it difficult to predict what kind of barometer readings would result from what's commonly available on the market.

I wanted to keep the baro range as tight as possible so as to minimize any undesirable effects from adjusting that interpreted range really far from a plausible reading. I also fixed the ambient temperature to read 70* F by using a resistor in that circuit, since seasonal ambient temperature ranges have enough influence that they could very easily skew interpreted air density enough to push my desired air-density table selection from one set of expected tables into another (again, due to the fairly tight range I have set up with my air-density select table).

Like you've mentioned, and I am happy to echo - it's far from ideal. But I'm working with what I've got.

[Jim P 2.0]

Rather than having to put in resistors, etc. the sensor scaling tables can just be set to only show one temperature no matter what. When I mentioned resistance of the rotary switch positions doesn’t really matter, the reason it doesn’t really matter is because when you pass 5v though it back to the ecm you only need to note the voltage of each position the ecm sees and rework the baro scaling table so you have an upper and lower voltage boundary of each position in a baro range that doesn’t trigger faults, states, etc associated with low baro readings, plus there are other tables that need to be adjusted as well

[B00STJUNKY]

Rather than having to put in resistors, etc. the sensor scaling tables can just be set to only show one temperature no matter what. When I mentioned resistance of the rotary switch positions doesn’t really matter, the reason it doesn’t really matter is because when you pass 5v though it back to the ecm you only need to note the voltage of each position the ecm sees and rework the baro scaling table so you have an upper and lower voltage boundary of each position in a baro range that doesn’t trigger faults, states, etc associated with low baro readings, plus there are other tables that need to be adjusted as well

Gotcha. That would be a nice way to do it (rescaling sensor transfer functions for baro and ambient temp).

I looked through my calibration just now, and wasn't seeing those transfer functions tables available for either baro or ambient temp. I did see them for boost pressure sensor, and rail pressure sensor.

Is that something you've added to your interface through user defined parameters?