Thinking of exhaust mod

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7duster4

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I have been reading about h-pipes and x-pipes and am very impressed. Especially with the x-pipe design. My Duster currently has full straight duel exhaust that was installed in 2006. I was debating about having an x-pipe welded in the current system. But now I am thinking about doing an h-pipe. My biggest concern is the sound. I have read the x-pipe design quiets down the tone whereas the h-pipe makes it sound more muscular and louder. Is this true? I would assume welding the h-pipe in would be much cheaper. My engine is a mild 318. Right now I am running 318 manifolds but plan on having 340 hp's in the near future. The mufflers are from midas. I forgot the name of them though. But I really like the sound.

So would an h-pipe be an effective mod to my exhaust? I know there are people here who have switch from nothing to one of these designs, what are your thoughts?

All info is appreciated. Thanks.
 
I have a pypes system with the x-pipe . Right now it's hooked up to the stock 175K mile 318 with a set of flowtech headers . I like the way this system works at idle and just cruising around it's pretty mellow but give it some gas and it has a raspy snarl ! It never seems loud but I sure notice how quiet it seems after I shut The car off . Will be interesting to see how it sounds after I drop the new 360 in !
 
Any sort of a crossover, be it an X or H pipe will quiet and mellow the exhaust note. It will also help exhaust system efficiency by letting pressures equalize between the pipes. Don't expect miracles, but the improvement should be noticeable.

If noise is your goal, 40 series Flowmasters should get you there.
 
LOL @ the Cheif. YEP! You aint kidding.

Not every exhaust will bennifit from an X system. The design is very useful in scavaging. (sp?) What Prine was saying by pulling.
I've ran into guys bitchin the lost time at the track after installing a "X" pipe and they promtly went back to true duals.
 
Thanks for everyones feedback.

I stopped by my local midas today to get an approximate estimate. First I asked about welding in an h-pipe. He seemed confused why I would do such a thing. Saying there would be no advantage in flow or increase in horsepower. But if I really wanted it done he would have to look at the car to give an estimate. Said he would have to fabricate something. I thought it would be a simple job, just weld in a 2 1/2 diameter pipe connecting the two near the back of the car. Sounds like I should check someplace else to get a second opinion. I wouldn't think it would cost too much money and take too much time. But I could be wrong. Im sure doing an x-pipe would be much more expensive.

I do understand the x-pipe design flows better. Am I correct in this: X flows better than H. H flows better than nothing?
 
To a degree, yes, combo dependent.
If the engine is low powered, an H will do fine. An X would also be a bennifit, but it's also a cost vs power gain issue and it would be expensive for little gain.

Same idea on very powerful engines. Sometimes, a true dual exhaust with sewer pipe size exhaust pipes is what it needs and performs best with.

The main idea of a X pipe is for scavging. (SP!) If you have stock heads and a single pattern cam, the X will help huge

It's a very combo dependent thing.
 
I haven't had an H-pipe in 20 years, but from what I remember reading in the hot rods mags, isn't the crossover pipe supposed to be smaller than the exhaust, like 3/4 the size?

Oh, and I'd find another muffler shop. IMHO, any muffler guy who hasn't heard of a crossover pipe wouldn't TOUCH my exhaust system.
 
If it's a fair amount cheaper then go with the H-pipe but if the price is right there's no reason not to go with an X-pipe. The sound will decrease a bit but a swap to louder mufflers will help that. Look at modern V8-powered cars, not a single one has "true" duals or even an H-pipe; all of them that have dual exhaust have an X-pipe crossover. Also, the ideal place is supposed to be calculated with the exhaust you have and on most systems is a few inches behind the transmission pan (mostly for easy access to the tranny) but that may not be ideal depending on the engine/header combo.
 
Mopar put an H pipe on the GTX 440 engine,
but not on the 340.

If the factory didn't think it was worth the $$.....??

I think it might help if your at 400 hp plus,
but, otherwise why bother.

I don't have the crossover on my car.

318 with a cam.

http://www.youtube.com/watch?v=Ud8mci4rjFU
 
T

The main idea of a X pipe is for scavging.

SCAVENGING!! Exclamation points are optional.....
Not being judgmental....I still to tell myself it's i before e accept
after c and I'm 50 <cough cough> some years old.

Cavemanmoron...duals looks so cool when it's freezing outside and the steam
is popping out of each side.
 
An exhaust system is a function of flow capability based on the engines needs. Basically, up to 500hp, 2.5" is all thats needed. The critical point is the amount the mufflers flow in CFM. Usually, people put more than enough pipe, then put mufflers on that don't flow as well as the pipes. Generally speaking, straight through style mufflers are the only ones that flow as much as a straight pipe. Dynomax Ultra Flow and Hooker Max Flow are good examples. For your 318, I doubt putting any type of crossover is necessary. Besides, I would venture to guess that any local muffler shop would ruin your exhaust doing so. I have had so many BAD jobs done at exhaust shops, I have a bad taste in my mouth for any of the compression bent systems that get done.
 
I had headers and true 2.5" duals out the back with Dynomax Ultra Flow mufflers. It was so loud at even cruise you had a hard time carrying out a conversation. I had an H-pipe installed (cost me less then $20) and it was night and day difference. It is still plenty loud especially when you get on it, but now you can talk without yelling. A crossover pipe of any kind will reduce the volume some, and help it breathe better, but it certainly isn't needed in all circumstances....just my $0.02
 
I have a 40 series flow masters with an H pipe with dougs headers on my 340. I'm looking to get more out of it and I've heard to straight pipe it or to put header mufflers. I don't want to make the mistake of doing something stupid.
Thanks.
 
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