I have a few things I'd like to try to get sorted out, some not exactly Viper related, but similar. Like many, I love the nice crackle and pop of my exhaust when coasting down and have looked into the subject a fair amount. I've read every explanation from lean to rich to no cats and beyond. From what I can tell, it seems both rich and lean conditions can cause it. This makes sense to me as either way could potentially leave fuel unburned in the cylinder (either too much to burn or not enough to start combustion in the first place). Some claim the popping is bad for the exhaust and will ruin the cats and mufflers in cars, though this was a factory feature in the earlier gens and doesn't seem to have caused any major havoc. Others claim some of the methods of achieving the pop are actually beneficial and help to cool the engine down (not quite sure how on this one, need more info). Also along these lines are both the small bursts of flame (typically between shifts), and even flat out afterburner style consistent blue flames as seen in cars like the new P1 and Aventador. Obviously this can't be too detrimental to anything or I highly doubt cars so ludicrously expensive would let something like this happen. The main question I have on this is how they acheive a constant flame like that? Typically these are mid/rear engine cars, so the exhaust is pretty short and I can see this have a contributing factor, but is it possible on a longer system? The no cat argument also seems to be invalid here as I'm fairly sure the stock P1s and Aventadors are required to have them, so there must be something more to it than just dumping fuel in the exhaust. Both my mother and I are fans of the race car appeal of entertaining exhaust, but I'm curious what all it takes to pull it off. On a similar note, but not quite as Viper related, I have a 5.7 Hemi I transplanted into a 67 Dart with an aftermarket ECM. I'd love to try to put a similar crackle and pop into the exhaust if I can as I have come to like the racier nature of the sound. Would any tuners out there be willing to divuldge some of their exhaust popping secrets? I've read the somewhat obvious ones of dumping fuel in the exhaust and lighting the spark off late, but I could see this causing bad things eventually. Seeing as Dodge found ways to do it to stock cars without hurting them, I'm curious what the least dangerous method is of tuning this in.