Hi Ronnie,
This is a good first step, but you really need to open up the exhaust by adding a free flow exhaust system with less restrictive mufflers (I suggest 3-inchers on each side). The Corsa Track works really well if you aren't going to add headers, but is too loud when headers are added, in my opinion. When I first put the Corsa Track Exhaust on, I noticed that the exhaust drip (condensation) that I had from the stock system became an aggressive "spray". This took a bunch of heat out of the car and added hp / tq and a much better sound. If you decide not to do the Corsa system their are others. I chose to go without the crossover to reduce heat behind my back. If this is an issue for you, you may want to consider this type of system. If not, a system with a crossover is quieter.
Good luck,
Dan
By the way, a small group of so Cal viper owners is planning to meet at Crystal Cove next Saturday morning Oct 16. If you're available, come on by and talk to some guys who have made some various mods and get their feed back.
