Thinking true dual would be a problem this day & age. Once you put cross over for = pulses you are pretty much back to stock. Not knowing your vehicle would it require additional O2 sensor? What would the CPU think?

 

Yes it would require another o2 sensor if yours only has 2 and you'd have to redo computer so it can adjust fuel/air mixture on either side of block. Doing this would be a project and like hydra said unless you have a jacked up system, it wouldn't be logical.

 

i wouldnt need to do this if i only did one muffler with dual out though right? ive ony done this on older trucks with no o2 sensors or cats so im not sure

 

Correct, only one post cat is required to properly keep the truck running properly and let you know of any cat problems. All the post cat o2 sensor is there for it to let your engine know that your catalytic converter is performing well. Just make sure if you're doin it yourself that you have a mount in the piping to insert this o2 sensor.

I have seen engines do crazy things if this o2 sensor is missing or there is not enough/too much back pressure so make sure your welds are great and make sure the way you route the exhaust pipes is good for a decent flow.

 

Since it only uses one O2 sensor to control fuel mixture to begin with you could use only one in one side of your duals and it would be fine. The post cat O2 is only there to monitor the cat convertor and you could either build a sim and eliminate it that way or have it tuned out in a mail order tune. I think there could definately be a gain with a good true dual x pipe setup on the durango but you would have to build it right and out of mandrel bends with at least 2.5 inch pipe.

 

Nevermind after quite a search there are almost no good headers for the durango and unless you want to spend big bucks for custom headers or a pretty penny for the Edelbrocks I can't see much of a gain from them because they all have tiny collectors. It would be much simpler and probably net about the same gains to go with a good mandrel bent three inch cat back.

 

For "true dual" you would require two o2 sensors or you could cause disaster. With true dual that means two catalytic convertors and the upstream o2 sensor is also meant to monitor heat and consistency between back pressure and proper flow.

With dual from headers with only 1 o2 sensor, you could have an issue on the #1 cylinder side (the factory o2 sensor is on #2 cylinder side) and it would not show up because on true dual theres no "X" or anything its just straight from header to cat to muffler to exit.

With an "X" I've seen it send some ridiculous back pressure in these rigs and not to mention the exhaust is fighting which sides it's going to exit. IMO if you're going to do a true dual the correct way, do it as I mentioned and not doing an X.

BTW, I am speaking from experience I build a '90 camaro from the ground up and did a true dual the way racers do it and the best all around performance. "True Dual" is just that, true dual where one exhaust does not intersect the other exhaust. If you're going to just do an X might as well save the time, effort, and money and Y at the headers to a common cat convertor that Y back out to dual mufflers.

 

even on my "408" i run a 3inch from headers back, 3inch y-pipe into 3inch single pipe /performance hi-flow cat into stainless walker turbo muffler ....pressure is prefect and sound is hair-raising lol

 

Ya but you got a stroker!


I would just do a 3" CAT back into a single muffler and single 3" out.

If you want the dual look you could always do the single in dual out and run 3" CAT to muffler, then 2 1/2 inch duals out.

Or you could do true duals with a single CAT on each side all in 2 1/2 pipe.



I had a motor bored 30 over, P&P heads, custom intake, 52mm Fastman and blah, blah, blah, and I didn't even need to get headers! I had a 3" CAT back single and that was it. I was thinking of doing headers and almost bought a set of shorty headers, but then I ended up selling it.

Unless you are going into a serious build you are wasting your time and money period! You need to make a desision on what you plan on doing FIRST, then do the exhaust build to take full advantage of the build, not the back-assward thing first.

 

From what I have seen there are no good headers for the durango anyway. The eldebrock tes seem to be the only thing out there with bigger than a 2 inch collector. I might have missed an offering out there but I saw nothing on the market that would be worth the effort of install.