Avalanche Exhaust System Upgrade

ChevyAGoGo · November 28, 2001

Has anyone upgraded the exhaust system on the Avalanche? If so, what did you go with? Is the input pipe 3 inches and the output pipes 3 inches? Any problems with fit since most outlets on the majority of perf mufflers are 2.5?

gandolphxx · November 28, 2001

I have an AV 2500 - 8.1L - installed Gibson single side + K&N - really nice combination - pepped it up.

Greg · November 28, 2001

I have the Gibson single catback and it's a 3 inch pipe all the way. A local speedshop wanted to put on a Flowmaster 40 with dual 2 1/2 rear pipes.

ChevyAGoGo · December 1, 2001

did you guys do the install yourself? looks like a torch will be needed to remove the pipe frlom the original hangers.

TahoeJeff · December 1, 2001

I installed the Flowmaster 70 on my 2001 Tahoe 5.3 ( your stock exhaust is like mine ) and it sounds great! I just checked my mileage and I am getting .5 mpg better and I have been dogging it most of the time to hear the sound. I should have 1 to 2 mpg more when I start driving normally again. I went with the single 3inch in dual 2.25 straight out the back with 3 inch dia 18 inch slash tips. I have lost no torque (maybe even gained) and have no resonance at all. From 0 to 50 it sounds great ( real low and deep rumble) I can't wait to drive it now! then quites down on highway so much you could not tell it was there. It is a great muffler for this vehicle. I can't beleive how all the shops locally tried to steer me away from the Flows! What a shame, people that take their advice our really missing out! I bought the muffler from Truck Performance and had a local shop do the pipes. I have a total of $ 325.00 for everything.