gman7589

iTrader: (1)

i have a 01 z28 and i just put a set of Jet hot long tube headers with a 3 inch collector and my neighbor has a hydralic pipe bender and wire feed welder that he is going to come over and help custom make a true dual three inch exhuast that comes out in front of the back wheels with dyno max mufflers he now says that we should use smaller pipe then 3 inch because there will not be enough back pressure and i will burn up my valves and be buying a new engine for the car with in a month or 2. i did some reading on the forum and found that everyone thinks that this is a myth but no one mentioned if it would happen if you use 3 inch pipe. i am not installing cats on the car. so i was wondering if anyone has a 3 inch custom set up that is working or some info to prove the guy wrong or right.thanks.

4mula

i really havent heard of any ls1 cars burning up valves

slik98z

um if you have the emmisions stuff on still (your A.I.R and Egr) with lt's you can burn up the AIR check valves from the different exhaust pulses caused by the lt's. in order to keep them from doing this you have to make restrictor plates or put in block off plates.
btw 3 inch piping running out the sides...its too thick, you'll scrape alot. use 2.5 inch piping for that purpose alone.