Hey guys, I recently purchased a set of long tube headers, 2 High flow cats for my 01 5.4L SCrew.... I called the exhaust shop and he said that when they run a true "dual" exhaust that they go from each Header back and out w/o any sort of H pipe or x Pipe... Now I am concerned that I am going to loose quite a bit of low end w/o having some sort of set up, am I correct??? I mean most modern cars all have some sort of crossover setup.... the exhaust shop says no... but logic tells me i need it... BTW they are 3" headers which I am going to then reduce down to 2.5" exhaust all the way back. Any info or feedback would be appreciated!
thanks

 

You'll definately want an H or X-pipe.

Why couldn't he put up either?

 

I have true duals with no crossover on mine. Everybody says I should have lost alot of power, if I have it wasn't much. In fact I am pretty sure I gained some, it seems like it breaks the tires loose easier now, and doesn't downshift as much. My brother got his done a couple weeks before mine with the same setup but minus mufflers altogether with similar results, he does alot more highway driving than I do and is getting better milage too. I do alot of in town driving and am still in the stage of wanting to get on it to hear it, so mine has gone down.

Another thing too, after spending alot of money on your truck your mind can do funny things to make things feel better than they are, especially when price is envolved.

 

Well almost every muffler shop here in town is not willing to touch anything that has to do with emissions/cat converters... so I am going to fabricate my own exhaust altogether! But I would think that some sort of x-pipe would be best for it, but if you have had luck not running one then maybe i dont need it?? anyone else care to chime in on this?

 

definetely worth the boost in tq[put the x pipe as close to the collectors as possible-phil

 

OK I drop the cash and got the Dyno tech headers with Hflow cats the y pipe would it give any more power or TQ with X pipe and true duels truck sounds sweet but I want every Once of power Also I have Flowmaster SIDO

 

For any performance exhaust system, some type of crossover connecting the two sides of a dual exhaust system is important because it acts to balance the two banks of the engine. The common H-style crossover is good at balancing sound pulses between the two halves, but does little to promote scavenging because the exhaust gases tend to follow the path of least resistance, which is straight through each pipe rather than taking the 90-degree turn through the H-pipe into the other half of the system. In an X-pipe system, however, where the two sides of the system intersect, the gasses have no choice but to intermingle as they pass through the junction. This promotes improved scavenging effects by smoothing out uneven exhaust pulses from the engine’s firing order. It also helps quiet down the exhaust, resulting in a mellower, less raspy tone. According to Magnaflow, the faster acceleration of the gasses through an X-pipe causes them to flow in a linear fashion parallel to the walls of the tubing rather than tumbling. This “laminar” flowing gas is much quieter than tumbling gas, resulting in an exhaust tone up to 8 decibels quieter than a traditional H-pipe.

 

X pipe all the way !!

 

X pipe

 

H-pipe baby!!!

 

Some shops will put stuff on but won't take it off. I know shops get inspected for cats laying around without paperwork on them as to what was wrong with them and why they were removed. You might ask if you take it off and maybe stick the headers on it if they will take care of it from there.

 

another ??, do you know if the cats have to be the same distance away from the motor on each side?? I ask because I am going to have to run the pipes down the passenger side then dual it off at the rear, thus making the driver side pipes longer for the exhaust to exit, so I want to know if each cat has to have the same distance from the headers.

 

Well I installed the headers last weekend and and they sound amazing!! It was a tedious job taking the old stuff out, putting the new headers on was not as bad as I planned, just a few bolts that were a bitch. I would suggest running an all thread tap before putting in the new bolts just to clean out the threads! Truck is a little faster off the line but really open up at highway speeds! I went ahead and kept the to stock cats, and made an x-pipe (which I recommend as well as a few shops I talked to) then dualed it off using 2 flowmaster 40 series mufflers. Did cut the egr tube and used about 5" of high temp silicone tube, everything lined up perfect! I ended up getting the pacesetter longtubes and made sure to prime and paint them with some 1200 degree engine paint. had to extend the wires for the o2 sensors, and i also used a pair of MIL elimnators on the rear sensors, and no codes! all in all it was a good modification, not easy to do, but not super hard, just time consuming!