I am under the impression that a 175 shot on a small block chevrolet is about as big of a shot as you should run with pump gas, due to detonation problems with bigger shots.

Is it safe to run over this, like a 200 shot or more, with pump gas?

Does using a progressive controller increase the amount of nitrous you can run with pump gas?

 

I don't think you "need to" use high octane or race fuel for a 200 shot. Just retard your timing according to manufacturers specs. The race fuel might help prevent detonation though.

 

Well, if you run race gas then you won't have to retard the timing as much... It's been said that you lose almost 20 hp for every degree you retard your timing.. If you want to run faster, I would mix in a little race gas, and not retard the timing as much... Of course, some people like to be super safe, and do both (race gas, and gobs of timing retard.) This does increase safety, but at the same time it hurts performance... I've got a 2nd gen camaro with a 10:1 383 running a 300 shot... I have the ignition pull 6 degrees of timing when the nitrous hits, while running 114 octane race fuel. It doesn't detonate at all. Rule of thumb would say to pull out 12 degrees (2 per 50hp) but with high octane race gas, the detonation tolerance level is WAY higher... Just my .02...

 

I run a 175 shot even with my 6 p.s.i. super charger on 93 pump. I do however pull timing with my m.s.d.