Hey everyone, I have a 2002 Ram 1500 with the 360ci engine (5.9L gas), with a PowerAID TBI spacer and an AIRAID CAI. Looking to go from single exit to true dual exhaust. Have flowmaster on it with 3 IN all the way from cats. Anyone have suggestions on whether I should use 3in or 2.5in pipes for the new exhaust?? What would be better power wise?? or fuel economy wise?? Not to worried about the gas mileage though, I only get 12mpg as it is. Thanks. (sorry I accidentally posted this twice, this is the one I wanted to post)

 

single 3" into muffler and 2.5" duals out is perfectly suitable for your application.

..and it's technically not considered a True dual as that is 2 separate pipes from the headers to the back. Any Y-pipe contradicts a "True" dual set-up.

 

yea i was about to say.. cus i got a the same truck (year,enigne etc) alos keep in mine that if you do decide to go TRUE dual than your gonna have to do something about that lonely 02 sensor.

 

if you are going to do a "true dual", two mufflers, i would not go bigger than 2 1/2 because you still need some back pressure. even if you were doing a si/do i would still use 2 1/2. 3" would be good for s si/si.

 

Negative. Back pressure isn't good. Velocity is good.

Pipes that are too big kill velocity, which in turn kills the scavenging of spent exhaust gasses from the cyls, which reduces the amount of burn, which results in less power.


I'd recommend a single 3" all the way back, an edelbrock air gap intake manifold (I keep hearing reports of major fuel economy and power gains) and a good cold air intake. You've already got one, but does it draw cold air, or just underhood air? The throttle body spacer might as well be a crystal ball, imho they're junk.

 

Thanks for your suggestions. I was wondering about that. I still want to go true dual (2 mufflers), so heres another way. How about using 2 1/2in pipes with a crossover, be it an X or an H?? Or would there be power loss?? I'm new to the truck business, I used to have an 03 Mustang GT with H-pipe crossover and noticed power gains, though maybe its not the same with a truck.

 

ive heard of people doing X pipes, just remember that we only have 2 02 senor on one cat. i dont know if taking one side away from it will reduce the oxygen flow thus throwing of the sensor into "not enough air". unless ur talking about cat-back dual?

 

True..... but how about changing out the 02 sensor and running one on each side along with two high-flow cats??? I thinks this may solve the problem, I cant delete the cats, as it is illegal in some states including the one I live in.

 

i have true duals with 2.5" pipes amd 3.5" tips, no mufflers with an x-pipe. sounds great. I do have a hemi though so i have dual cats from the factory.

 

Just bought an 07 4.7 Ram. What's the loudest Flowmaster? And should I replace the Y-pipe? Thanks