Straight piping a 94 sierra

[CountryBoy93]

Hey guys i am looking into straight piping my 1994 sierra but im not sure what size piping to get. where should i start?

 

[98trck]

I loved it when I lived in Linville Falls NC in the mountains of Avery county I had my truck straight piped just replace the muffler with the biggest diameter pipe You can and use the rest of the exhaust system
yes it is illegal I did it thirty years ago
a friend did get busted for it but he did literally have straight dual pipes out the back

PETE

 

[jdgreen]

If you take your cat and cut the top of it open and clear everything out of it then put a nice flomaster on it with three inch it sounds awesome. If you get busted without a cat though it's a $10000 at least it is in Indiana where I'm from. I wouldn't go bigger than three though.

Brent

 

[miahweedgmc]

pipes

Just a note ...If your running Headers beware of entropy from too large and of an exhaust pipe. I put 3" Flowmasters 50 series and then 3" all the way out on my 71 and it created a condition know as "Entropy" where it altered the resonance and created turbulence in the exhaust system. Sounded terrible, like a bad rapping out of the pipes. Sounded great when I ended the exhaust behind the cab but worse when I took it all the way back. So I needed to reduce the pipes down to keep the exhaust gases from cooling off to quickly until they left the exhaust system or shorten the pipes to get it to sound better.

 

[CountryBoy93]

well i want it straight piped from the headers back. no muffler, no cats lol just straight pipe and tips. or possibly a flowmaster super 10