A relay, used as you've described, has demonstrated advantages in the 90-92 cars to i.e.,
"reducing the current in the switchgear" - as it applies to the LT5 starter (in this case). In fact, the 93-95s the switchgear was (in effect) isolated in a fashion similar to what just as you are describing. So, in general theory, your using a relay to isolate large current paths from "switchgear" is a valid endeavor...
generally speaking.
However...
- In this specific application, such a relay would be redundant, due to the use of the "coil driver module" doing the job of you relay mod
- Lead lengths between the DIS and the coils is already very short (by design), thus minimizing line resistance losses in the wiring and other issues*, so there's no practical advantage there
- *Pains are taken to shield the critical wiring from EMI (pulses) in the proximity of where such a relay would have to be placed to have any hope of doing any good; which would expose the relay (and more importantly) the wiring to the DIS to the introduction of EMI...a bad thing at high RPM especially.
- Perhaps (to me, anyway) the main reason not to mod is the fact there is no problem with the factory setup - far as saturating the coils goes**. (Parts that don't exist never fail, and they don't cost much!)
Now, IF we want to address ignition in a truly positive way, going to a CNP like the LS motors use, or COP like Ford uses on some of their performers...is worth a thought; some performance gain might be had there (but a topic for another discussion/thread)
That said, I bow to anyone with actual experience with this mod as applied to the LT5
SPECIFICALLY.
