AEM 30-6905 Universal Programmable EMS-4 - Manual (Page 183)

Page 183 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
The spark plug gap on forced induction engines should be reduced REGARDLESS of the type
of ignition system. We have read many instruction manuals for aftermarket ignition systems that
recommend that the plug gap be opened up for better flame propagation. Although this
recommendation may have had some merit when vehicles had carburetors, it does not apply to
modern engines with electronic engine management systems. The smaller gap on forced-
induction engines requires less spark energy to arc across the ground and the electrode and