Exhaust Questions

[ajpthng]

As most of you know I'm wanting to put an exhaust system on the Dodge, I've seen several set ups for dual exhaust and many different opinions on the best set up. I thought I would post it up here and see what kind of answers I get. My truck has 2 cats then a Y pipe and 3 mufflers and many bends before it exits the back of the truck, it has potental for a true dual because of this setup. If I were to go true dual what would be best, straight back, staight back with an H or straight back with an X? Or should I leave the Y pipe and run a single in dual out or a single in single out?

What would you do and why? What would be best and why?

[99TJ]

I'd say run a true dual with an X, most hotroders seem to think its the best setup. I ran just a straight dual set up on my 82 shevy. I would have prefered an X or H, with the 450HP it had woulda been nice, but never got that far

[78calico]

An X or H pipe would ideally be directly after the manifolds or header collectors to work to it's potential. There is probably not a cross tube at this position because of the cat set-up. I'd be interested to hear Kelly's take on this. Making the Y an X and running duals from there would probably be your best bet IMO.

[ajpthng]

To give everyone a better idea of how the exhaust looks on my Dodge here are a few pic's.






This is an aftermarket set up but you can see where the Y crosses over from one side to the other. That would be the location of the X of H if I were to go with True Dual, I would also be adding a heat sheild of heat tape to keep it cool going that close to the gas tank.

[akdsmer]

If I was going to change the stock configuration (which I don't think I would) I would run a "super single", that being a larger diameter single pipe back from the cats. This would be quieter due to the two resonance chambers helping to cancel each other's noise. This would also be quieter, cheaper and fit better. I must be getting old, because I'm tired of loud exhausts, especially on the trail when I want the window/top down so I can enjoy nature. Those that share the trail with you would also appreciate it. Yes, my Mustang will be duals, H pipe and rather loud, but that's a musclecar. It's SUPPOSE to be loud and annoying.

Most dyno tests don't show much difference in X or H pipes, plus almost all the few ponies are at the high end. X pipes are expensive, or if you make them, a small pain in the arse. If going to duals, just stick a pipe in between the two at some convenient point and roll with it. If you need to drop your et's by .01 so that you can "be in the 11's (or whatever bracket your in)" then maybe the extra work for the X pipe might be worth it.

Search Hot Rod...or was it Mustangs and Fast Fords :confused: in the last year to find an interesting dyno test to determine the lack of improvement. Keep it stock, put your money into Huaneng Power International Inc. (HNP) and see what happens in the next 3 to 5 years.

[akram]

Like Kelly said, one large diameter exhaust is better than duals. There is a reason you see most diesels with one instead of duals. But it also depends on what you want to accomplish. If you want the sound duals is the answer with a cross pipe some where. Get rid of the last "muffler" it is worthless. And remember, exhaltion process still requries inhalation.

[akdsmer]

remember, exhaltion process still requries inhalation.

Clinton would disagree with you on that one.

[mousee]

After doing several duels on trucks now I can truly say that they can be a pita to do right on most stock setups. The biggest problems I see most people do is going too big on the pipe diameter. For torque (were a four by should live) you want exhaust velocity. A single will perform well and can be made to sound good too. Three inch single with a flowmaster super 44 sounds baddass. I wouldn't recommend exiting in front of the tyre either I have seen the corrosive results of this in Fairbanks. Ever try to remove a wheel thats been behind an exhaust stream to long?

There have been several customers that we did duals and they came back later to get an H put in for better sound and have noticed a seat of the pants differance. Now this may be that they have just built it up in their minds but...

If it was mine I would run some nice long tube headers, new cats,flowmaster super 44's, and 2.5"(v8) duals all the way back and exit at a forty five out the rear corner. I would H it over about six inches behind the collectors. But that's just me...

[99TJ]

Like Kelly said, one large diameter exhaust is better than duals. There is a reason you see most diesels with one instead of duals. But it also depends on what you want to accomplish. If you want the sound duals is the answer with a cross pipe some where. Get rid of the last "muffler" it is worthless. And remember, exhaltion process still requries inhalation.

would that fact be that cummins diesels are a straight 6 and only has one exhaust manifold anyway? Can't say for the v8 diesels but I would say they run a single pipe for the same reason that gas v8's run a single, its cheaper and easier to run for the factory..just my $.02

And I will also add that, I have read somewhere, might have been hot rod or soemthing back in the days I was all about HP, that the best way to run an H pipe is to run the vechicle for a while, till the pipes get hot, then you find the 2 hottest parts of each pipe, and then connect those two points with the H pipe, there was something about that being the spot with the most pressure, and the H will relieve the, forgive my english, most presssureful area of both pipes, giving you the most increased HP, that most are looking for by doing the X or H pipe...I'll stop m rambling now

[akram]

Going up in size of the exhaust pipe on a single exhasut you are increasing how fast, and how much at one time, of gas the vehicle will expell. Now with duals you are doing the same thing but usually with two smaller exhasut pipes. It is also usally cheaper to do just a single. The bends and such play a big role in it also. There is a limit on the size. Once you hit a certain size tubing it's pointless to go bigger and then there is the debate of back pressure.

[68bronco]

dont glass packs add back pressure? i have 2in pipes dual runnin straight out the back with packs and no muffler in my bronco, it sounds nice but i want somethin quieter for the trails also i have heard of systems that are actualy two setups hooked together with relay switches to you can run quiet and loud performance exhaust like you can switch back and fourth when you need it

[akdsmer]

I don't want to be misunderstood-an H pipe or X pipe increases power, just recent dyno testing seems to indicate the X-pipe doesn't do nearly as much as originally thought, plus the expense of an x-pipe kit, which is $80 in Jegs, doesn't make it a worthwhile expense over an H pipe.

Keep in mind that modern OBDII systems (on vehicles with EGR) need some backpressure or you may get EGR flow codes. Try to get that diagnosed for $30.00...

[SHoppe715]

...systems that are actualy two setups hooked together with relay switches to you can run quiet and loud performance exhaust like you can switch back and fourth when you need it

You mean cutouts that can be opened up to be basically open headers and then closed to run on the street? Some are just caps that you remove by hand and there are some $$y ones that open and close with a dash-mounted switch.

[68bronco]

the dash mounted switch is the one i heard about my friend wanted one for his 98 firebird i was thinking of designing something like that using cables

[akdsmer]

Jegs part number 720-5424 $47.99 cable operated exhaust cut-out for 2" id exhaust.

The electric version is 815-ec250sk for a 2.5" id exhaust. A nice tidy $460.00

[sevenslats]

^^^^^
I see someone's been doing research on this already.

[68bronco]

those electric ones are cool but for the system we are talking about you would need two valves for each pipe to close off one and open the other and if you run dual your looking at twice as much money but i want to build one just for fun

[Mr Anderson]

Heres an idea for an exhaust

http://static.howstuffworks.com/gif/truck.jpg

Not very good for noise though.

[sevenslats]

You know tom loves that. It's got his rims!
:troutslap: