I'm sure this topic has been covered time and time again however there seems to be some debate over it.

I really would like a real world strait answer on what typically you can expect.

I'm thinking about swapping the small little piping coming from stock exhaust manifolds; and Y pipe to all the same size piping. I think the stock piping from Y pipe to cat and cat back is 2.25

What could I expect as far as performance Low End/High end and daily driving if I change it.

Would i loose low end acceleration.. would i gain?

Just looking for a down to earth honest answer.. to make the best choice possible.

I'm really looking for quicker acceleration (Quicker RPM increase from Idle to 3K through all gears when accelerating)

Truck Details in my info.

 

Typically by increasing the diameter of the pipe, you lose low end and gain high end power. While there is obviously a lot more to it than that, that's generally the case.

 

years ago i had chrysler 300 J with a max wedge engine. i took it to a really good muffler shop. the pipes was big, cant remember how big. the guy said if you reduce the pipe size at the last 2-3 inches by 20-30%. it reduced loudness by a LOT, with no reduction in power. and it really worked

 

Well that's cool; I dont mind it being loud.. just want faster response Idle-3k

So what is the best solution to help out the lower end of the RPM range other than Cams and forced induction

 

So my best bet to not mess with pipe size and just replace the y pipe? Would that not drop back pressure as well being that is what we are messing with is the +/- of back pressure against the motor?

I would think increasing just a tad bit would allow it to flow quicker,better and give better response.

I just dont want to loose low end and gain high end. And the truck feel like a 4 banger from a stop and take even longer to ramp up to 3k

I just want a little better acceleration and to have the b@lls when i stomp on the gas and not act like I'm driving a 6 cly on the highway. My 302 never felt like it was lacking power.. this 318 feels that way (unless I'm shifting manually and hammering the pedal )

 

if the bottom end response is important just keep he duration, lift low. the cam grinder expert is your friend. IF, a BIG IF you drive ONLY in town go to a 4.1 rear gear. i have a 2001 dak 3.9 V-6 was getting 9 mpg. changed to a 4.1 , mpg goes to 14.1. i cant say you would get that. mine did that cause it let the trans to shift to overdrive 1400 rpm, at 35 mph cursing. you might get that by adjusting the trans rod, but i dont know.

 

Yeah my issue is I'm a 4x4 and i dont want to sacrifice the offroad abilities; just trying to put a little more pep in her step when i push the gas.. I think i'm asking too much of the ol' girl. :P

 

a little more cam will do it. but you must keep lift about .430-,460 , and duration to 268 duration. i had a engine with that spec, in a 1965 chrysler 300 L 413 ci. a new yorker had the same engine but less lift and duration. mine had 20 more HP, and VERY drivable. i got the same mpg. but all that is old school stuff. but the same idea will still work.

 

Get some good headers and run a true duals 2.5" catless exhaust. That and a cai and your golden.

 

Catless I'd love unless i do it so it so i can take on and off for emissions. :X

People including exhaust shop told me running duals will decrease my low RPM.. And that's the range i'm trying to improve.

I read an article the other day saying if you open up the short pipe right off your manf. it will cause the exhaust to slow down doing exactly opposite being it cools off cooler and looses its speed.

Would the same thing apply to headers and Y pipe; even if i kept single system and same size* piping i have now off the headers to the y pipe?

At the end of the day my end result I do not want to hurt the lower RPM.. I want to help it increase faster.. rather I'm pushing it light throttle or WOT.. Just trying to help out the 4x4 on the road.

But I also dont want to break the bank.