In this weeks episode of Tech Tips we will be explaining how to set up the Auxiliary injector map on our LT-16c and LT-32c ECU’s.
The main reason for having an Auxiliary injector map is so you can add additional injectors to your engine & activate them in “stages”.
Doing it this way allows you to bring each stage in progressively as the boost level rises, which in turn will make your tune much “smoother”, by switching the injectors on only as they are needed.
On the MicroTech tuning software, the mapping for the primary & secondary injectors (the main load map) goes to a maximum of 41psi. So from 41psi onwards, any additional fuel you want to add must be done using the Auxiliary injectors.
The mapping for the Auxiliary injectors is split into 2 screens. The “Idle” screen & the “5 Bar”screen.
Adding fuel from 0psi to 41psi is done on the idle screen, then from 41psi onwards the adjustments are done in the “5 bar” screen.
The Auxiliary injector mapping “starts” on the idle screen at lower boost levels, then continues onto the “5 bar” screen as the boost level increases.
(Just imagine it as if you got the 5 bar screen & attached it to the end of the idle screen)
Ultimately, what you’re aiming to do with the tune is have your primary, secondary & auxiliary injectors all working at around the same m/s values when you reach peak boost.
On a typical rotary drag race tune, most guys start to bring the auxiliary injectors in at around 17-18psi & gradually increase the numbers as the boost goes up.
The pictures will give you a good idea of how the different screens should look when the tune is finished.
A few important tips for you to remember.
* You MUST have the same m/s value at the 41psi mapping point on the idle screen as you have on the 41psi mapping point on the 5 bar screen. This will ensure the mixtures remain stable & there is a smooth transition between both screens as the boost pressure passes 41psi
* There is nothing in the software that needs to be “switched on” to activate the Aux injectors. The moment the ECU see’s a m/s value in the boost side of the idle screen, it will begin to pulse the injectors once it reaches that mapping point
* Because the load map only has mapping points to 41psi, if the boost goes above 41psi, the primary & secondary injectors will continue to pulse at whatever value is in the 41psi mapping point (regardless of how much higher past 41psi you go).
#injectingthefastest
