View Full Version : preferred exhaust system for 5.7l
Chevy4sure
07-24-2002, 07:24 PM
Soon, I am due to replace the exhaust system on my 5.7L '98 Chevy.
Currently I am running the stock exhaust pipe to the catalytic converter to muffler to single right side exhaust.
Would I increase performance (hp and mpg) by running 2.5 inches pipes from the 3-inch catalytic converter to dual flo-thru mufflers to 2.5 inches pipes out the rear? I realize the sound may "rumble" a little more from quiet I now experience...that's just fine with me.
Additionaly, has anyone added the throttle body extension for improved performance?
Thanks.
bowtieguy
07-25-2002, 07:46 AM
Yes you will see performance increases in mpg and hp with a free flowing exhaust system. However, I would also recommend you look into replacing the stock air filter element with one from K&N. If you increase flow on both sides of that Vortec engine you will see a greater increase. You do not need the entire K&N system, just the replacement filter. It will cost around $50 and comes with a 1,000,000 mile warranty simply clean it and reinstall from time to time depending on driving conditions.
bowtie,
have you run these K&N filters and what has your success been? Do they clean easy? I too am planning on changing my exhaust system on a 96' 5.7 Vortec as my dad did it to his newer one and has had great success....but I like the idea of offering greater flow on the front side as well.
TJ
oldbullhauler
07-25-2002, 02:14 PM
Travis,
Installed a K&N about a year and a half ago on my 97 5.7.
Wouldn't be without one. Mileage and performance are noticably better.
Jeff
bumps2
07-25-2002, 05:37 PM
I have a 95 Chev 5.7 K-1500,,I installed a Flowmaster, two chamber muffler and it helped mileage some but not a great deal. Best though is the sound. Not too loud, just a nice, low rumble. The muffler has a 3 inch inlet and two, 21/2 inch outlets. I reduced my outlet pipes to 2 1/4 inch based upon advice from the shop that installed the mufflers. They said the smaller pipe would last longer because it would run hotter. Installed the muffler and pipes in 1998 and still good as new. Hope this helps