I am running a HSW wet kit, 100 shot. At high RPM before the shift, I hear a rattle noise. It doesnt seem to be detonation. Bottle pressure was at 800 psi. Could this have something to do with it? Motor sounds fine without nitrous. Any ideas???

 

800psi will make you run rich...
but that doesnt explain the noise

 

800 psi is fine, it you're hearing a rattle at the top end, I would say it is detonation. Have you had your A/F checked or are you running a wide band? I would get that checked, or I suppose you could bump up your fuel pill a size or 2 and see if it goes away..

 

the car was tuned by karteck and it never had an issue until now. I even have 6 degrees pulled out because i was planning on running a 150 shot after i upgrade the fuel system.

come to think of it i just had esc tune just the transmission ie. **** points and converter lock up. i wonder if the tune was reset while they were in there. o no no good.....