I'm using the MSD retard box to automatically retard the motor when I activate the nitrous system. It seems to do the job. That system uses different degree "chips" to set the amount of retard you want. I have seen an adjustable timing control also where you can adjust the timing on the fly from the drivers seat but I haven't tried that one. I know some motor builders that don't recommend that system for fear of inadvertantly dialing in too much advance and hurting the motor.