This is for the guys thinking about going true dual exhaust, I see a couple guys saying you get x amount of HP increase if you go dual exhaust and then I have read guys say the V6 you will lose HP because unlike the V8 the 6 needs back pressure. I have read this several threads not just the one linked and one guy say not even talking about back pressure said his car was diff slower with the true duals.
I do not know which is true I am new to V6's I would research it before you go true duals if you do not want to lose any HP or TQ.
Seems if this back pressure loss HP & TQ is true it might be wise to go with the Y pipe when going duals and even better not so free flowing mufflers for the duals.
Not trying to start flame just letting you know do the research & make your own decision
quote:
"The comments about backpressure causing losses in torque and HP on the bottom end are coming from owners of older V6 Mustangs that have dynoed before and after exhaust changes and reported the results. Stock V6 motors have reacted poorly to true duals " http://www.mustangforums.com/m_573138/mpage_2/key_back%2Cpressure/tm.htm
I have true duals (not JBA true duals, REAL true duals with no X or H connecting them)
And, I'll be the first to admit that I lost a little power by adding them... Not much, but it does feel a tad more sluggish... Actually, I don't think I 'lost' power, I think it just moved higher up the RPM band.
I'm working on the 'long term plan' and not really interested in the short term gains I could see. I plan on adding a charger (most likely a turbo setup of some kind, still refining that plan), with a turbo, you get all the back pressure you could ever want
I have true duals (not JBA true duals, REAL true duals with no X or H connecting them)
And, I'll be the first to admit that I lost a little power by adding them... Not much, but it does feel a tad more sluggish... Actually, I don't think I 'lost' power, I think it just moved higher up the RPM band.
I'm working on the 'long term plan' and not really interested in the short term gains I could see. I plan on adding a charger (most likely a turbo setup of some kind, still refining that plan), with a turbo, you get all the back pressure you could ever want
Thanks for (honest opinion) posting I am deciding how to set up my exhaust I don't have a lot HP/TQ as it is now and IMO I don't want to lose any more of either. I am thinking of going with a Y pipe another stock V6 muffler little (little fab muff) for left side. I am thinking this should diff keep the BP. You know I have a stick and going through the gears not even hard maybe shifting at 4K you hear the engine rumble up and single exhaust is little loud its a healthy sound not loud but healthy. So with duals it look nice not as loud as after market of course but will have a little louder sound vs single.
I have been also reading up on this V6 I have no plans for any of this right now, but if I ever decide to go power adder the way this engine is designed internally from what I read IMO it would be turbo only not supercharger you are right on.
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Joined: 10/11/2005 From: Southern California Status: offline
i have the JBA true dual exhuast kit and i have not noticed any loss in power compared to when it was stock. i have not ran it on a dyno but if there was any loss, it was not big enough to even notice. if anything, i've felt a slight increase in pep when i take off at green lights. i would love to see dyno results on a h-pipe true dual so that i can know what my car is pushing. the sluggish feel that StupidTodd is feeling could be a loss in TQ, not horsepower. i'm sure it runs like the wind when jamming on the highway.
I have to agree 110% with ya on that , the seat of the pants isn't accurate its an opinion, but for someone to admit after installing dual exhuast thet their car feels slower is pretty honest.
I like to see some 100% proof one way or the other but I have a feeling the BP is needed on the V6, and I do not want to lose through the low RPM range and pick some up when I on the car and then at 4000 or above (i pick some up) when I shift at 5200.
If back pressure is a real issue, then yes going to a Y or H pipe should be just fine. A tune will also help along with a CAI if you are going true duals. Most people go with X, H or Y pipe. These all should be fine on near and long term horse power gains. Going true duals from the cats would be for signifiant power adders, and I would also replace the headers at this time.
You should be fine with a prefab kit.
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Joined: 8/16/2005 From: San Antonio, TX Status: offline
Trust me, going with a true dual exhaust will not cause a loss in either horsepower or torque. As long as it is done with some thought. All our engines are is big air pumps power is created by moving air in and getting air out, and if you get rid of the air coming out (e.g. less restrictive exhaust) it should serve to create a vacum effect to pull more through the car. This process is the same with any engine regardless of the fact that if is a 6 or an 8. When you talk about losing power, you might be refering to the loss of low end torque. (www.3.8mustang.com) has a good article about exhaust size. It says that anything over 2.5in as far as duel exhaust is too much, because you will loose some low end torque (seat of your pants feel.) However, if you have more Air coming in (e.g. supercharger, turbo, NOS) theoretically you should need to have more air coming out. How do you think those ricers get away with those HUGE exhaust system, because their engines have to rev to make power. And they have half the displacement that we do. For example Honda S2000 (2.0L 247hp and 153 ft/lbs of torque) Can you see the difference? Unless you build a high end screamer, which for us would require redoing the internals, you don't need a huge exhaust system. I personally have the manual and I have a custom dual exhaust (h-pipe) with flowmasters and headers (2.5in exhaust, 1 5/8 in headers). I have the Mustang GT 17's, and I still find it hard to find traction when I take off. Of course a LSD might help. It is actually really loud and drowns out the radio when I have the windows up. I will tell you though. A true duel exhaust (no x or h pipe is not good for your car.) Your engine will actually start to run like two different engines over time. One bank may run lean. Also I am sure it creates a lot more vibration as there is balancing out of the exhaust pulses. If you are running True duels , no h or x-pipe. I would really consider getting one.
If back pressure is a real issue, then yes going to a Y or H pipe should be just fine
Like you said IF the BP is an issue
Wouldn't the Y pipe be better than the H pipe Y=more BP ----H pipe = less BP <------more like true dual exhuast less BP.
I am not doing any other mods I want to install a dual exhuast but I do not want to lose any HP or TQ in my low RPM range, in the future no plans now maybe slight maybe if a decent turbo comes out in year or two and its cost (cheap) effective:)
ORIGINAL: TJ Thanks for (honest opinion) posting ....
No problem, I was fully aware that I would lose a little backpressure when I made this change, and that I would end up losing power because of it. I viewed this as a necessary evil that I must endure until I can get to where I want to be.
quote:
ORIGINAL: Sancho805 the sluggish feel that StupidTodd is feeling could be a loss in TQ, not horsepower. i'm sure it runs like the wind when jamming on the highway.
You are absolutely correct.
quote:
ORIGINAL: TJ I have to agree 110% with ya on that , the pants isn't accurate its an opinion, but for someone to admit after installing dual exhuast thet their car feels slower is pretty honest.
I like to see some 100% proof one way or the other but I have a feeling the BP is needed on the V6, and I do not want to lose through the low RPM range and pick some up when I on the car and then at 4000 or above (i pick some up) when I shift at 5200.
Sorry, didn't get the car on the dyno before and after. Running on a dyno generally costs money, and I have plenty of other mods that I could better spend said money on.
I would say I lost power between 1800-2750, but gained slightly at 4000+.
I agree pants isn't accurate, but it's all I gots to base my opinions off of.
I just do not want to lose any (the liile I have)of my HP or TQ (TQ is more important than HP) going to dual exhuast because its for curb appeal for me and slightly louder exhuast
Keep the stock diameter (or a maximum of 2.5" diameter) but go with a 'tuned' exhaust to get better sound. Going larger is not the way to go if you plan on keeping the car stock.
OK after all the input from everyone a little more research & derf links (thanks), it comes down to this if I have it right the little V6 engine requires back pressure and if you remove back pressure bigger true dual exhuast by getting the exhuast out faster (upset the flow balance)without a good amount of more air coming in (keeping engine stock) bigger cam, bigger heads etc you are lose HP & TQ & in the low end RPM range.
OK after all the input from everyone a little more research & derf links 9 (thanks), it comes down to this if I have it right the little V6 engine requires back pressure and if you remove back pressure bigger true dual exhuast by getting the exhuast out faster (upset the flow balance)without a good amount more air coming bigger cam, bigger heads etc you are lose HP & TQ & in the low end RPM range.
Mostly correct, if you do go dual exhaust you just need to be leary of going with 2.5" on the V6. 2.25 would be the biggest I would recommend. If tuned properly it will still sound hella good. The mufflers can have 2.5" at the tips. You will not lose anything in the power department and have an excellent stepping off point should you decide to do a more intensive mode later on (I.e. turbo or S/C)
< Message edited by Derf00 -- 11/9/2005 4:44:27 PM >
So my next questions to you guys/derf. Do I have the following right?
I will be keeping my engine stock but want dual exhuast curb appeal (its a Mustang) slightly louder sound.
So going with a Y pipe and another stock V6 muffler on the left side (keeping my engine stock) will not affect my back pressure enought to upset the flow balance no loss of HP or TQ.through the RPM range
X pipe with free flowing mufflers on a stock engine you start to upset the flow on a stock engine.
The H pipe would be even more free flowing.
True dual exhuast with free fow mufflers on a stock engine would lose HP & TQ in low RPM range
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Joined: 8/16/2005 From: San Antonio, TX Status: offline
errgh, It seems that no matter what you hear, you still think that you will loose torque and HP. This isn't always true. As long as you are conservative with it. Even the V8's will loose power if you go with too big of an exhaust. Keep in mind that your engine has to move air, that means in and out of the cylinder. A conservative dual exhaust will give you more power than a y-pipe. Ford just didn't want to put it on the V6, because of cost/competative with the GT issues. '
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Joined: 10/11/2005 From: Southern California Status: offline
based on Derf's links (very good, informative info by the way) true dual h-pipe wont disrupt flow pulses in any significant way unless the diameter of the piping is too large. its seems that the kits available (JBA, Magnaflow, Borla) all use 2.5 inch piping which seems appropriate for the 4.0L engine (basing this on the info from the links). "True" dual with no X or H pipe may be a "slightly" different story. i'm still not convinced that backpressure is what makes the V6 stang what it is. seems to me that it was designed more for cost effeciency so that more people can afford to have a stang, LIKE ME!! if that was really the case, i'm sure performance mfrs. would create products to increase backpressure on the '05 & '06 Stangs (just doesnt make sense). besides that, it seems clear that backpressure makes the engine work harder to exhasut gases and take years away from engine life (although it may help in the TQ department). i'm pro-life and want my engine to produce strong performance without it having to work as hard and decrease engine life. still waiting to see some dyno results on a dual H-pipe exhaust!
Posts: 2620
Joined: 10/11/2005 From: Southern California Status: offline
quote:
ORIGINAL: 05redfireV6
errgh, It seems that no matter what you hear, you still think that you will loose torque and HP. This isn't always true. As long as you are conservative with it. Even the V8's will loose power if you go with too big of an exhaust. Keep in mind that your engine has to move air, that means in and out of the cylinder. A conservative dual exhaust will give you more power than a y-pipe. Ford just didn't want to put it on the V6, because of cost/competative with the GT issues. '
i totally agree with you on that one. when it comes down to it, its all about sales and business. if ford put duals on the V6, GT sales would be a heck of a lot lower than they are now. they would look the same but be cheaper even though its a smaller engine. as a result, people would brush off the GT cuz of the price. this is just what i think. anyone else with other knowledge or opinions, please share!
So my next questions to you guys/derf. Do I have the following right?
I will be keeping my engine stock but want dual exhuast curb appeal (its a Mustang) slightly louder sound.
So going with a Y pipe and another stock V6 muffler on the left side (keeping my engine stock) will not affect my back pressure enought to upset the flow balance no loss of HP or TQ.through the RPM range
X pipe with free flowing mufflers on a stock engine you start to upset the flow on a stock engine.
The H pipe would be even more free flowing.
True dual exhuast with free fow mufflers on a stock engine would lose HP & TQ in low RPM range
Not following you on the 'Another Y pipe'. Unless you mean an 'X' pipe. It won't negatively affect your hp or TQ unless you go larger than 2.25" with a stock engine. Not sure on the Free flowing mufflers.
H pipes are typically used for equalization between the exhaust banks. At higher RPM's they don't add anything to the RPM band like the X pipes can.
Most of your backpressure is in the Cats and single exhaust pipe not the muffler(s). I don't know how that's affected with true dual and two free flows though. I would do a search on this board to find out more about exhaust combos that work well with the mustangs. Keep in mind, 2.25" max. diameter and an X pipe are where you want to start.
The mufflers are where you can have the majority of your sound 'tuned' to what you think sounds good. Different Brands will be tuned differently. As long as you have a solid foundation on the rest of the exhaust you're free to swap the mufflers around until you find one with the sound you like.
SO.....If i have a steeda intake and Jetchip on my V6 5-speed, what should i be looking at if i want sound(little louder and more american), performance (maybe a few more horses, i DONT wanna loose any), and looks (gotta have one tail pipe on both sides) or is this "dream" exhaust system just a fantasy of mine, is their an exhaust systems with all those features?
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True dual exhuast V6 = lose HP & TQ ? - 
