HIGH FLOW MUFFLERS VS CAT BACK

[LTHL VPR]

Your numbers are not surprising to me. We have a large database of Vipers (around 50) on our in-house Dynojet. In the stock Viper cat-back exhaust system, although it begins with 2 1/2" diameter tubes, it actually shrinks down to 2 1/4" around the differential area. The Borla system uses 3" diameter mufflers and tubes (except the first couple inches that connect your stock system to your Borla mufflers. There is quite a difference in flow.
Keep in mind that your year Viper has a strong cam too.

Take Care. If you have any questions, feel free to give me a call at the shop: 408.562.1000.
-Wayne

 

[Joel]

The OE in sill mufflers reduce to 1 3/4" inside. Thats just awful and must be a major bottleneck in the gas flow, by contrast the standard cats "appear" relatively ok and do a large measure of the silencing.