Originally Posted by TampaSSEi95
actually i wasnt planing on messing with the timing because i have no way of doin it. i only have a 55 shot and its wet so i shouldnt lean out on it i also have ngk tr55`* in so im good on that part and alot of new sensors had a problem for a while couldnt quite figure it out but i finally got it it was the egr valve so i just got rid of it
If your wet shot has seperate fuel jets, then get a spare couple that are a few numeric sizes larger than the one recommended. (i.e. bigger fuel jet gets tried out first, then work back down toward the smaller, leaner fuel jet.)
One approach to altering the ignition timing is the same way the PCM commands it. (Pin A on the coil pack is the EST signal from the ECM to the coil module.)
GM, in their infinate wisdom, kept the signalling the same as on the HEI ignitions that predated the coil packs (it'* kinda a "super" HEI module)
With that, you should be able to insert one of the aftermarket timing retard units into the ignition wiring between the ECM and the coil pack. They all work the same, taking the timing signal from the ECM and modifying it before it reaches the ignition module. The way the modules work (I'll use Crane Cams TRC-1 as an example) you dial the amount of timing retard you want. An input lead from the nitrous switch turns the module on when the nitrous solenoids are being opened, and the module starts altering the signal from the ECM to the ignition module under the coils...dumping the timing by the number of degrees you dialed in.