How do i tell if my car is detonating?

[Trick Pony]

I just got done with my S trim install, and im trying to set my retard box. Im using the recomended setting on the MSD box but am trying to fine tune via the dial. The problem is, ive never experienced detonation, and i dont know if i will be able to hear it. My exaust is very loud as i have headers, an off road H pipe and 40 series flows. Does anyone have any tips?

 

[illwood]

Detonation sounds like someone is shaking a tin can of rocks under your hood. I wonder if anyone is hooking up a knock-sensor to a timing retard for your setup.