Little JB4 update for you meth heads with some detailed directions on how to connect your progressive meth mapping. Very simple to do and a nice upgrade over the JB3 setup!
I had a chance to play with it a little this weekend and its a blast to drive
Quote:
With the JB4 we've setup a dedicated analog input specifically for methanol control. This allows a flow sensor, like the CMGS/VC2 we support, to inform the JB4 exactly how much methanol is flowing at any given moment. This flow information is included as a logging channel called "meth" and mapped in a 0-100% format. For the more advanced users 100% = 2v. The typical output is .1v per 100ml/min giving a full sweep of 0-2000ml/min.
Meth logging:
1) Connect the CMGS/VC2 orange wire to pin #15 on the JB4 DB25 connector. If you are part of the first batch of 100 alpha boards you must also connect a ~20k resistor in the wire to protect from voltage surges as the CMGS/VC2 turns on. The second alpha batch includes this resistor on the board itself. If you're unsure email in a photo of your board to ask.
2) Set your CMGS/VC2 v1.07 or higher parameter #12 (5V output mode - orange wire) to 0. Enabling it to output .1v per 100ml/min of flow. If you are using an alternative flow sensor consult with your flow sensor vendor for the appropriate settings. If you are using a previous version of the CMGS/VC2 you will need to upgrade it to 1.07 or higher to take full advantage of this feature. Firmware v1.07 has been designed specifically for progressive methanol mapping and that feature was not included in their 1.06 and previous firmware. CM offers a mail in firmware update program. Email info@coolingmist.com for details.
3) Using a normal map (1 or 2) do a series of WOT pulls with your meth enabled and observe the meth parameter in the logging software to ensure proper movement. With X scaling set to 100 note the highest percentage observed.
Progressive mapping:
Our alpha progressive mapping systems allows the JB4 to smoothly and precisely raise boost and related tuning as a function of methanol flow. You define how much boost can be increased by and what methanol flow is required before boost will be increased, and the JB4 increases boost as a linear function of methanol flow. If flow exceeds 2000ml/min an overflow failsafe is automatically triggered.
To enable progressive mapping:
1) Under the methanol tab set the "meth additive PSI" to the desired boost increase at full flow. A suggested starting point is 4psi. Note this field is currently not a decimal so you will need to enter 40 for 4psi, 35 for 3.5psi, etc. We will correct this in a future interface release. In addition we plan to add an autotuning function for this field in the future which will determine the appropriate boost increase based on timing and other DME feedback.
2) Boost is added on top of the map 1 boost curve which is 13psi peak. So a value of 40 will provide 17psi peak. Peak boost is also subject to the boost limit set under user adjustment. If the base map plus your methanol additive add up to more than the boost limit you have defined the JB4 will automatically limit the boost target to 1/2psi less than your defined boost limit during operation.
3) Fill in the "meth flow max" with something slightly lower than your maximum methanol flow. For example if you are seeing 40-45 you may want to select 40 here. This represents the point at which the JB4 will assume you are at your maximum flow and deliver the full meth additive boost increase. In the examples below with an M8 nozzle I'm seeing around 40% during max flow which corresponds to approx 800ml/min. The actual meth flow may be higher or lower than the voltage reading unless you carefully calibrate your flow sensor. Something most never do. So don't get too wrapped up in the actual voltage unless troubleshooting a specific problem or it's way off.
4) Progressive methanol mapping is only active when map 3 is selected.
Old school:
For those of you who want an intermediate solution before you can upgrade your pre 1.06 CMGS/VC2, or for those using an alternative that provides only a simple high/low signal, we've made the JB4 backwards compatible. Entering a value of 1 under "meth flow max" will revert to JB3 logic where voltages higher than 2v will add the full boost additive.
Attached are a few logs I took tonight playing around with the settings. The first log is shows adaption testing along with the meth flow in action, second is a series of runs where I disabled the methanol physically half way through the log, and the last is manually reducing the methanol flow using the controller settings and the JB4 changing it's target accordingly.
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