Hi im new to this site and i have a question I have a 1999 dodge dakota 5.2L . And i was wondering wich exhaust setup would be louder the one i have now or the one im thinking about doing. right now i have a 2half inch stright pipe all the way back with no muff or cat, with a 4inch tip. and it blats now, but i was wondering if it would be louder with 2inch true dool with no cat or mufflers. Please help

 

all a muffler will do is muffle the sound or change the tone. straight pipes are pretty much as loud as it will get. you can go duals an that may help make it "louder". i dont see why you would want to make it any louder than it is now. that sh*t gets annoying pretty quick.

 

its not to bad to me i love it. I live im maine so very bodys truck up here is like that.

 

yeah but when you ahve to drive any long distance, you will hate life. also it will kill your gas mileage. (murder it, trust me on this)

 

Im just wondering wich one would be louder thats all. And for my gas mileage i get anywear from 16 to 17 its not bad at all. way better than my old 99 3.9L . But all i want to no is wich one would be louder and blat more. thanks

 

no what i am saying is that not only will you be harder on it (to hear the "roar") but if you have true straights, you lose your backpressure. loss of backpressure equates to the exhaust running past the oxygen sensors too quickly, messing the computer up, telling it that the engine is running too lean and therefore the computer (which controls the amount of gas injected) will always dump the most fuel it can into each combustion cycle. i have a 4.7 with an aftermarket 1 in 2 out muffler with my stock cat. my buddy has a 4.7 (durango but still) with a straight pipe (no cat) into a T that comes straight out the back of his truck. i can get 15-17 mpg or so while no matter how nice he is on it he is getting between 10-12 mpg. this is due to the sensor **** up therefore killing your mileage.

hope that helps. hell if you want a true straight, be my guest, i'm just trying to give you some information about your options.

cheers. welcome to the forum

 

Okay thanks alot!

 

This is actually wrong/right at the same time. Let me explain...

Having straight pipe will decrease BP yes, but any free flowing exhaust can trip codes via pcm on our trucks, even with a high flow cat some trucks has thrown codes, the way the o2 sensors work has nothing to do on how fast the exhaust moves past the sensor, the o2s sensors are there to read the exhaust content and make sure your "cat" is working properlly. The 1st o2s before the cat figure out if the exhuast is to lean or rich and send data to pcm to correct it, if needed. The rear o2 after the cat is only there to make sure the cat is working properly (cleaning the exhuast) if you get any type of free flow exhaust or cat less exhuast the rear o2 must be rigged to not throw codes.. the rear o2 will NOT make your motor run rich or lean, its the 1st one.

One way to rig the o2s on our trucks is to just zip tie it to the frame rail, as long as the rear o2 reads SOMTHING diffrent from the first o2 it will not through codes and you will be able to pass inspections since most people dont use sniffers anymore and only OBDII or OBDIII readers which just read the pcm codes and pass or fail it, depending on check engine lights.

Another way it to get a o2 simulator for the rear o2, just plugs in and sends a certain .0v to the pcm making it seem like you have a cat.

as for loosing gas mileage, yes it can happen, but not as bad as he makes it seem, having NO BP at all is pretty bad and useally decreases your low end torque, but since these 5.2s and 5.9s of ours create so much at low rpms, you wont notice much diffrence.

Although somtimes having the just right BP for say just removing the cat can give you an increase in MPG. This is simular to why cars over seas without emissions control like the yaris can get 40+ yet over here in the U.S after adding all the emmision crap it gets little over 32 or so.

a 5.9 durango getting 10-12mpg city doesn't surprise me and is about right for the 5.9.. My truck city gets about 11-12mpg and about 13-14mpg highway running at correct A/F Ratios. While i open it up i avg around 8-10mpg.. its great, WOT bypasses the o2s and pcm runs in Open Loop dumping fuel like no other... gota love mopar.


o and to answer the question about exhuast, you have about 2 ways to make it louder..

1. Cut the pipes shorter instead of running them all the way back and have them DUMPED/TURNDOWNS before the Axle.. this will create more resonance that can set off car alarms and rumble the ground and be heard better all around the truck instead of right behind it.

2. Open headers.. loudest ever.. I ran open headers for about 2 days (the weekend) since my exhuast shop was closed and had to wait to put on the rest of it, so i was having some fun. There was no backpressure, i have vacumm gauges in my truck and with no BP my truck would only have about 7 instead of the normal 25, it was to loud and just idleing by cars set the alarms off.. i do not recommend this, but its your truck and your life...

 

Okay thanks a lot for the input. But i just want to no between the 2 wich one would be louder? My trucks loud now but not this loud !http://www.youtube.com/watch?v=nlAhp2zqe30

 

true duals will be the louder of the 2 that you asked about

i have an actual exaust dumped before the rear tire, it sets off car alarms still,
it was louder for some time, no cat and a rice rocket muffler, i liked the sound...but i'll never go back, nothing like your exaust shaking your own truck and cars 2 lanes away when you go under a bridge,
i did run open headers for about 3 minutes. fück that, no low end at all,
(i did have the pipe to the cat with the resonator still, no choice)

i have the 2.5l so when i say no low end i mean NO FÜCKING LOW END