[Dark_5.0]

Originally Posted by Dark_5.0

That would be detonation.

Retard the timing about 3or 4 degrees. You can run stock timing with a small shot but 100 shot and up you need to retard it for sure.

I believe the rule of thumb is 2 degrees for every 50 shot of nitrous.

I highly reccomend you pull all of your plugs and make sure you didnt melt the electrode off any of them.

Its also important to run a .035 or so plug gap with the larger shots of nitrous with a colder plug. I am sure you know this but just making sure.

BTW: What engine are you running and whats done to it that makes you shift at 6800rpm?