secondarries

[Hib Halverson]

Originally Posted by Pete

As everybody knows my secondaries have been out for about 10 years.

My understanding as to why chevy put secondaries was emissions and gas guzler tax.(snip)

Exhaust emissions and beating guzzler had nothing to do with the existence of the port throttles. In fact, guzzler was never and issue with the LT5.

The secondary port throttles exist soley to improve low speed torque and throttle response.

Another point i would like to make is the C6 ZO6 with the exhaust flappers most replace them. (snip)

Actually, most C6ers with cars having NPP do not "...replace them". Admittely, some folks do swap an aftermarket exhaust for the stock dual-mode system, but more C6 people retain the NPP system but add an device ("Mile2Wild", "Exhaust Commander" and similar products) which allows them to manually control the exhaust bypasses.