Proper P01/P59 Hard spark cut LC and rev limter fix

[dubcrazy8392]

Messing with input data sounds like a hacky piggy bag thing that could really throw of spark timing as it cuts in and out.
Maybe there's some way you did it that's perfect though. Obviously, I can't say for sure how sane it is without knowing exactly how the ECU is programmed, or exactly how your code interacts with the stock code.

all this does is mask spark events via the crank sensor signal. there are literally 2 ways to achieve a true spark cut in these ECU's but the pitfall and limiter is the TPU that kills the first method with manipulating the dwell time. The fact that the TPU is in the road for anything ignition related and the fact that it cannot have its micro code reprogrammed is a major roadblock but if you noticed i said micro code that meant to me that the TPU handles only so much of the ignition calculation and it has to pass of any of its heavy lifting to the processor itself and the flash which is where i found at least one instance i could intercept this hand off and manipulate it for a spark cut. the problem im having with it now is its more of a saw tooth type cut, very harsh on/off effect. im working on a way to make it more cylinder selective cut to give more of a stumble effect like you hear in the MSD 2-step box or the lingenfelter launch control box. i think the missing pieces to my equation now are that i need to be able to retard the ignition timing and enrich fuel more. cutting on the regular ignition timing alone could be the major contributor to the saw tooth effect im getting. i've setup and worked with countless variations of launch control in many standalone ECU's and they each have their own approach at how they achieve this. some even have multiple ways of layering different types of cuts over each other. thats mainly in high end units though. over all i just need to get a better feel for how this engine works and go from there.

[AngelMarc]

For retarding, I'd look at AC timing adjustments. Either just hijack it, or duplicate it.