If you are trying to increase hp one of the easiest methods is to add timing advance. Dodge has always been protective of the viper engine by pulling timing near peak torque.
You pick up anywhere from 5-10 HP for every degree of timing advance, although it can vary and there is no assurance that you will see consistent linear accumulation of power - i.e. 10 degrees of timing advance doesn't assure you will get 50-100 HP...diminishing returns and you will also be limited by the physical quantity of air being drawn into the engine.
Let's be clear about what we are doing though. By advancing timing are igniting the air:fuel mixture before the piston reaches TDC so in essence it is controlled detonation, with the idea that by igniting the fuel sooner it allows for more of it to be burnt on the power stroke. It is easy to do but it's arguably not an engine-friendly way of gaining power...that being said, the Gen V engine is built with forged pistons and other durable materials it could probably handle the increased cylinder pressures you get with aggressive timing advance.
The PCM also forces the viper engine to run extremely rich at peak rpm, this is also intended to protect the engine from detonation. The theory is that on a hot day at the track the car will not detonate.
This is a pretty common configuration on modern performance cars which is why you often see a puff of smoke shoot out the exhaust when someone is shifting near the engine's redline
The problem is that you are giving away a lot of hp. It is all too easy to add timing and pull fuel on a Gen 1, II and III and get back some of that hp. There is no MAF sensor on the viper engine it is air density control. A lot of tuning was done with both the VEC and SCT, a large part of the tuning is an increase in the timing, in general that requires a higher octane. To go one step further tremendous hp increases can be had in boosted applications, when higher octanes are used used. With my Gen II, I have both 93 octane tunes and 108 octane tunes.
Obviously with forced induction you will benefit from using higher octane fuels since you can force more air into the engine. That's the name of the game, though. The more air you can squeeze into the cylinder the more fuel can be burnt and thus the more power can be made. Advancing timing does not require that the A/F ratio is changed and technically isn't a power gain - it's more of a power recovery, in that you are recovering the power that you already had but lost due to the tuning being biased toward reliability.
On a stock Gen V for daily driving, at this point any octane over 93 is not going to result in any positive gains. For long track events on a a hot day, I would not want anything less than 93.
I can agree with this, but I'd like to note that without resorting to forced induction you are limited by the maximum amount of air that the engine can inhale with each revolution, and therefore how much of said fuel can be burnt. You could do something like run nitro and double your engine power without going to forced induction.
