Ham-handed 2 step launch control

[Gianelli280]

Before I go swapping pins in and out til my fingers bleed, someone tell me if this will work... My aim is to limit spark by using a shift solenoid output of the PCM.

I'm using a th400 so no trans electronics are necessary, which gives me some options at first glance.

I have a roll control switch that I'm using for launch, and I've set that up (by a NO/NC relay from scavenged PRNDL inputs) to toggle the pcm into what it thinks is neutral and 2nd; this can be done for any pair of gears if I'm not mistaken.

My question is, by setting up a 2>3 WOT shift RPM at a desired launch RPM for example, can I use a shift solenoid signal to energize a normally closed relay for spark? If the thing is trying to shift, but only cutting spark, I'd believe this would function as desired. I'm assuming the shift solenoid signal is just 12vdc, which is what I'd like some clarification on, and what kind of dwell should I expect?

I understand this sounds tweeker as F***, but I'm waiting on parts. This is also a low buck build, so if a relay is the only cost, I'd be pumped.

[shinyrust]

how did it turn out?