I didn't really find anything on true exhaust for a V6. I was thinking about getting it done. I know that it isn't that practical and might loose a little power but I heard that it sounds pretty nice. If I did this it would be down the road and after finding out what I would want to do with it. Who has done it and any soundclips? I was thinking about doing it like this guys:

If I get it done it would come out the back and have a 2 in 2 out muffler mounted before the axel. Maybe closer to the axel and may run without cats. I havn't made up my mind yet on what I would like to do. Mostly asking for opinions, kits, or just get a custom job done.

Edit:
Where would be the best place to mount the O2? I was just thinking on a similar place where it is now but it would only read one side. And would like to add that the car already has headers and will be getting a cam and proted iron heads in a few months along with a 3.1 in place of the 2.8. I won't be running nitrous or FI. The car will likely stay NA for a while till I get a beater later on. The exhaust would be 2 1/4 exhaust and use a muffler like this Edelbrock which I understand sounds pretty good:

 

You would lose alot of back pressure, and from what a 2.8 V6 sounds like without an exhaust attached to it, I don't know how good it would actually sound...

 

???
I'm not planning on running open exhaust. I know that sounds horrible.

 

It will sound esentially the same with that muffler, and true duals.

 

Actually they sound pretty mean. I have glasspacks on mine and it rumbles like a v8. Only thing that gives it away is when I get above 3k and it sounds like it's turning a billion rpm.

A properly designed exhaust system will always boost power by helping the engine scavenge more efficiently. 2 1/4" tubing would be a little on the large side, but it would give a nice low exhaust note. A 2-in 2-out muffler won't benefit the exhaust the way a crossover pipe would, besides you can get a pair of thrush glasspacks or mufflers for less than the edelbrock. There's a whole crapload of math involved that I can't find right now that helps you determine the proper tubing diameter and length for a specified rpm band, but some of the basics are that both sides should be equal length, have an x pipe or crossover about 1/2 way down the exhaust and tuned to give proper exhaust velocity at the torq or hp peak, whichever you preffer.

 

I don't want glasspacks. I have a Magnaflow 2 1/2" on there now and it doesn't sound that bad. I know 2 1/4 might be pushing it. So 2" would be better? And I thought that a crossover pipe did nothing for V6s since the engine is naturally balanced or somehting like that. Glasspacks just don't do it for me personally, too much rasp. I want to stick with something like the Magnaflow, a straight through design. Flowmaster maybe for the sound. You got a soundclip?

 

For pipe size, I've seen a guide that gives HP vs Diameter. You can also look up info in the GM Performance book. I can look when I get home, but it tells you recommended header runner length, diam, and collector size.

Since the V6 is so small, i doubt you could outflow a single 3" pipe. If I ever get around to doing it, I'd like to see headers, with a calculated collector (Y-pipe) that join at the h-pipe area, with a single out. The area's of greatest concern in an exhaust system are:

header diam
header length
collector size
collector length to h/x crossover or tip

It seems that the pipe after the h/x crossover is of little concern, so long as it doesn't contribute to backpressure. You mainly want to setup good resonance, which happens in the header runners and then again between the collector and the tip.

READ ME

 

My head just exploded. I'm not going to get that involved into setting up the exhaust. I just want a good setup. I want to stick to something like what I posted above. What would you do for my car since you seem to know alot about exhaust? I would like to do something affordable. I would like to go with something like a Magnaflow muffler, they sound pretty good and are pretty unrestrictive.

 

What is your current setup? Mine is stock manifolds and y-pipe. I've tried a couple different cat-back setups. My current setup is a 3" mandrel that joins onto the 2.5" y-pipe. It was ghetto fab'ed up after i got tired of the 2.5" sidepipe. Niether have made much of a difference, as I have figured.

I consider anything behind the cat to be mearly for sound. Especially if you have a full length exhaust setup. Just make sure that its big enough (not too big like mine) and has mandrel bends. Then find a muffler to give you the sound you want.

If you are looking for power gains, grab an equal length header setup, and fix the nasty stock y-pipe. The stock V6 y-pipe passenger side seriously tee's into the driver side pipe. I guess that would be more of a t-pipe than a y-pipe! Anyway, lengthing the arms on the "y-pipe" and adding headers would be great.

 

You will loose alot of HP...

...because the 2.8L motor just does not have the volume of hot air to push all the way back that far in dual exhaust tubes. A V8 is 5.7L in general. Cut that in half and one side of the duals is equivilant to our entire V6 exhasut gases 'Almost" because we also do not have the CFM per displacement they have either.

Keep it single and you will have beeter performance-OR- Shorten the overall length of the exhaust to the rear and let it escape quicker in a shorter path.

 

I got a good exhaust on there now. Its Pacesetter headers, their 2 1/4 y-pipe to a 2 1/2 inch Magnaflow highflow cat to mellow out the sound a little, then 2 1/2 pipe all the way to a universal Magnaflow muffler, single exit. It flow plenty, I was just thinking about getting dual exhaust for the sound. I haven't heard anybody's setup before. I know a couple of people have done it. I would keep my headers and a 2 1/4 dual exhaust since the collectors on the headers are 2 1/4. I just havn't quit decided on exiting out the back or getting one of those boom tube tips to exit out the passenger side. I know that it is a little more expensive but I just like the idea of a side exit exhaust and it will have plenty of ground clearance.

 

I will strongly suggest you to save your money because "in MY OPINION" (this means you can do as you wish, but you are asking in a public forum for advice) you are going to be 100% disappointed with the results.

1) More weigh- slower car
2) Restricted flow- slower car
3) I do not have anywhere near the ground clearance for side dumps- If my car were 4" higher I still would hit them regularly going over speedbumps and driveways and the headaches it would incur having to constantly deal with leak repairs.
4) You wallet will be lighter so maybe you could at least run faster.

Trust me, trust me, trust me, Save your money. Ift will sound like crap at any substantial rpm above 2500. All this sacrific just to try and 'sound ' better at idle.

Again- this is just my opinion so rrespect the fact you asked and I answer as honestly as I could.

 

Right on. Sounds like you have everything going well then. The idea behind exhaust is to:
1) flow
and
2) setup reflecting waves for scavenging

Headers are the primary focus for scavenging. But some gain is to be had with doing collectors and full exhaust right. If you were to design it before hand, design to make it flow first, then adjust lengths to fit the RPM you built the flow around. Also construction technique can increase reflecting waves. Anytime you change the pipe diameter by 30% or more, you send a wave back towards the engine. Thats how x or h pipes work.

The problems with too large of an exhaust are low exhaust velocity. Low velocity means it will cool faster changing reflecting wave propogation as well as creating backpressure since the air in the pipe is denser. Also larger pipes will move the resonance down to increase low RPM tuning.

If I were you, I'd make a really nice y-pipe with the "y" at a point approx 40-50" away from the header collectors. Then go 2.5-3" out the back.

 

Thats also why I am asking the question, for opinions. There hasn't been much discussion on it that I have found. The boom tube tip is like 1" high and maybe something like 6" long. If there is no benefit then I won't do it. Everyone has reasons for their opinions on what would be beneficial. I don't expect to spend lots of money on this. If I go with the side exit then I already have half the piping.
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So basically run duals to say just before the axel then a single pipe over the axel.

 

my couz has a slowstang with a 6 he has true duals with flow 40's and a "H" pipe, it sounds GOOD for a V6 and i normaly dont like V6's with an loud exhaust

 

A friend of mine has a 3.8 'stang with Flowmaster duals and it sounds really good. Its doesn't have the rumble of an 8 but for a 6 it sounds damn good. I know mine won't sound as good as his.

 

50" from where the runners meet. That would be about mid chassis. The idea is the runner has 1 exhaust pulse every revolution. Its also important that they are the same length. Since its an even firing engine, the collector gets 3 pulses every revolution. When both sides join, you get all 6 every revolution. But since every time the pipes join you get more exhaust, they need to be a larger diameter. When you increase diameter you need to increase length to maintain the same frequency. The same can be said of speaker box ports. It wouldn't take much to do the math. But a good "rule of thumb" book would get you in the ballpark. Are your headers equal length? If they aren't, there would be less to gain by going through all this.

 

I'm not sure if they are equal length. They are pretty close though I believe. I'll see if I can find out. I'm pretty sure that the headers are almost equal length. Each primary might be a little longer than the other but not by much.

Edit: It appears that I was wrong. The headers are not equal length, I thought they were.

 

If they are not equal length and tuned to your hp peak (which they probably are not) you will loose whatever scavenging gains a tuned exhaust would afford you. Forget about tuning for cylinder pulses or resonance or anything like that because it requires a full on tuned exhaust system to be effective and it's overkill on your project. Figuring out the right diameter and length to give proper exhaust velocity is 1/2 the battle, if you do that you'll be ahead of 90% of the 'muffler shop specials' out there.

You won't loose hp going to a dual exhaust- the notion is absurd. Regardless of how much or how little 'hot air' an engine is pumping out into single or dual tubes it will still exit the tailpipe all the same, although exhaust velocity may decrease if too large a tube is used. The only way you'd loose power is if it were poorly designed.

 

Pacesetters are not equal length. Their only concern was ease of manufacturing and fitting the engine bay.

I have a custom made smog legal set that was attempted to be made equal length and even mine are not. It was not phsically possible in a 3rd gen engine bay going into a y-pipe.
My # 5 is 1 1/4" shorter than the 5 other primaries. all the others are equal length. (#5 is the back one on the pass side of motor)
http://www.cardomain.com/member_page...752_4_full.jpg

Our firing order + samller displacement is what make duals sound like crap opposed to the 90* V6's of Ford and GM.

 

You would have to run rediculously small dia tubing as it works its was all the way back to the rear of the car with 1.4L of exhaust gases. THe tubbing cools much greater rate than the entire 2.8L in a larger tube going the same routings distance. It would never make it- You WIL DEFINATELY lose big power.
Care to say this is wrong again, I will get and list Dyno results of testing I have done on our exhaust routing on the spec truck crew cheif on- Did I mention I am a NASCAR crewcheif. I do know first hand wht I am talking about.

 

I would like to see those. Nobody said you didn't know what you were talking about. All the guys who have posted know more than I do so I just read and form my own opinion.

 

Duracell Bunny- Show me the dyno results. On a nascar vehicle that's sensitive to a single hp I can understand huge power losses but it's not going to make that huge a change on a street driven vehicle that's not going 200 mph for hours on end.

Oh, and as for the o2 sensor if it's a single wire unit mount it the same distance from the cat as it was on the original setup unless you won't have them, in which case mount it about that distance from the head. If it's a 3 wire unit you can put it just about anywhere it's not heated by the head. It won't be able to read both banks if it isn't mounted on a crossover pipe, but as long as both banks aren't wildly off from one another (which they won't be with fuel injection) it should be fine.

 

I will bring the charts home and post some results and pictures. We keep the info at the owners house about 50miles from mine up in LA. I am an hour away (in low traffic) in Orange County so they are not immediately availiable.

People do not realise the importance of exhaust routing. THe smaller the HP, the more criticsal percentage wise it shows. SO on the contray to your last post, it does NOT show as much on a car putting out 800 hp as it does on a car putting out 330 hp, and it really shows on a car putting out a memre 150 hp at best like these little 60* V6's. A five HP loss is on 120 rwhp is a 4% loss. A 5 HP loss on an 800hp is still less noticable at a 0.75% loss of HP. Now 3.25% difference does not seem much, but let me tell you when it is married to a 3000+lb car it is a huge difference.

On a single dump 4" 62" long we made about 6 less HP than a 3 1/2" dump and 54" long. THe gasses on this 330 HP motor were cooling and slowing too much in just that short of a distance that we were loosing power.

The camaro exhaust routing is about 15 feet long after the primaries. Food for thought.
My routing on my Camaro is cut down by about 2 feet and made a noticable diffference on "my car" with my modification. I have one pretty damn quick 2.8 auto V6 "when compared to a factory bone stock 2.8 V6 Auto or stick.

 

You saw my custom header up in a earlier post. Here is a shot of the tail pipe section I have extensively reworked with several different trials and errors. THis rotuing is as most direct to the rear exit as possible and the muffler choices were also curcial in the overall flow. I have use a combuination of about 8 different mufflers and resonators on this car tayloring it to get the best feel and sound. I have probablyu done more experimenting in this department with the V6 camaro than anyone else ever on these boards.
http://www.cardomain.com/member_page...2_137_full.jpg

When I first put the current set of headers on the car, it feel on its face at about 4800 rpms from the performance so called Catback setup I was running before i had headers. It ran up to about 5400 without the headers smoothly, and then just that change hit a bit more power buit also hit a block wall at 4800. I then started screwing with it again and go it ticking much better just through tail pipe routing and muffler positionings. I picked up noticibly more power on both bottom and top ends and extended my power band range- just on exhaust experimentation.

I also run about 48psi fuel pressure through a billet 62mm throttle body. Stock TB's are 52mm, stock fuel pressure is about 38 idle and about 43 running.

Edit: ps- I am somewhat and oldtimer around this website. I have been around it for about 6 years I think. Seems every six months we get a whole new set of faces and names around here and the same subjects and debates come right back around.
My dinner break is over, gotta get back out to work on a current project in the garage. I'll check back later for any responses.

 

May I repeat what I said on #23?

Not going 200mph for hours on end, not making 800hp with a nascar engine.

A vehicle moving at 200mph cools the exhaust system MUCH better than one at 30mph and has a much better chance at cooling the exhaust to the point that exhaust velocity would be effected enough to hinder power production. Furthermore power loss would be proportional to power production- not all engines would loose a set 5hp. If a cup engine looses .75% of it's power so would a 2.8 v6 IF they were running under the same conditions. The v6 looses 1.125hp, the cup car loses 6hp. Then again what's to say that the change in tubing length and diameter didn't cause the change in power?

But since his car's on the street the effect on exhaust velocity would be negligible, if present at all.

It's the old argument of apples to oranges.

 

Well, after reviewing what you have, I think it would be best to lay off the duals for now. Especially since you don't have tuned, equal length headers. The added mass would probably slow you down more. Not to mention added complixity. Again, I'd focus on getting a decent y-pipe.

I heard the cool thing to do is to join the branches of the y's by pounding the ends into D shapes, and the stuffing them into a common outlet pipe.

 

I think true duals on a 6 banger is just way to much work and waste of money and all you end up with is all blow no go

 

You do not get it.
A minimal HP lose on a smaller engine is far more noticible WHEN IT IS ON THE SAME WEIGHT CAR than a larger HP loss on a much more powerful engine.
It is far more critical on these struggling little engines in these heavy cars. He will drop about 5 hp and will also add 50+ lbs of weight.

A car doing 200 mph does not necessarily cool better the exhaust. There is far less air rushing under the chassis on a Cup car doing 200 than your Camaro doing 60. apples to oranges.
Also, when air compresses against a surface it heats up

 

Nor do you apparently. He loses a mere 1.125hp due to cooling of the exhaust, versus the gains of having a much less restrictive exhaust system than stock. Cooling makes a negligable difference in overall power. Having dual exaust sets him up for further gains as he continues to modify his engine.

Regardless of what our oppinions may be he wants a dual exhaust system, so we should steer him in the right direction with it.

 

The back half of the exhaust is not as important as the front. To keep exhaust velocity up he could make the pipe smaller and it wouldn't hurt anything. I think he should focus on the headers, y pipe, and the exhaust leading up to the axle. Anything after that doesnt matter as the power of the reflecting waves are negligible.

If you are stuck on duals 2.8RS, it would probably be a better idea to do dual sidepipes. That would keep the exhaust short and save weight. Plus you would avoid any temperature loss arguments. I ran a side pipe with a 30" glasspack with a passenger side dump for a while. It was really loud and annoying. If you did a pipe off each side, at least you'd go deaf in both ears. Lol.

 

I estimate he will lose 5hp, not 1.25.

I also already gave you factual response explaining why the dual is too long routing to the back of the car- You failed to either read that, or if you did, you fail to respond with factual reasoning as to why you think it would in fact work. It will not 3 banks of that engine pushing exhaust gases consiting of about 60 hp 15 ft long in tubing will fall on its face EVEN IF YOU TRY AND REDUCE THE TUBING DIAMETER. Try this- put 15 feet of 1 3/4" tubing on a 600cc streetbike and see how the power drops dramatically. Its about the same flow and HP as those 3 cylinders feed each individual dual exhaust.

Now dispute this with reason.
You can NOT route the exhaust shorter dostance with side dumps on a daily driver without jacking the car so high you look like JoeDirt. You do not have the clearance.

Now this part is my 'opinion' and not necessarily fact- Even if the end results WOULD give a "plus 5 HP" result(which it will not, but lets say for kicks it did) I would still not recommend duals because of the headacre of ground clearance, the extra weight, and the cost to do it are all reasons why you could get that extra 5 HP other ways that I gaurantee the original poster has not done to his car yet. Also, It really is a car that most of you hoinestly should not waste your money trying to make fast. Sell it, cut your losses and buy a V8 becausse obviously you guys are trying to make a rocketship out of a tricycle. I am a rare case here. I have the money to buy pretty much any car within reason I wanted for my wife, I chose to built this car for her with the specific intend of being a very fun daily grocery getter and diffferent from the average minivan driving mom. It is not our "fast car" of the family its actually 4th fastest of 5 vehicle I own but it is the MOST fun to drive.

2.8RS you of course can do what you choose. I am simply giving back asked advice that I fell is solid first hand info. I will also say strongly that I would bet big money you would be more hapy with the sound and power of an exhaust setup more geared towards what I have then you would like after you spent alot of money fitting duals and then being diapointed. I am not trying to be mean, on the contrary, I am trying to convince you to save your money and not do this dual exhauist mod, I personally think in a month you will regret it after the initial cool factor of just having Duals wears off. Yes it a nice thing to boast about just like having the big stereo , the big rims, and the flashy exhaust tip- looks great sitting still at a car show. Not on a race track , and not for any other performance gain. With this said, if it is just looks and noise levels at idle you seek? then do it, but I warn you how crapy it will sound at 4K going down the road. From inside the car you might think its the snitz, but let someone else drive it and you will see just how pathetic it will sound in the car behind you with those two pea shooters pointing at them.

 

Single passenger sidepipe with glasspack. You can see the tip right in front of the tire and the glasspack near the RS emblem. I agree that it hung low, but i used the stock y-pipe. It could be made to fit higher up. Plus if you cut the tip to be flush with the ground.

For the record, I wasn't happy with it. Scraped speed bumps really bad, was really loud, but was better than my cat gut plugged exhaust at the time.

And its pronounced "Dirt-ay"

 

Let's agree to disagree.

I say higher exhaust velocity (even if only through part of the system) and larger capacity would benefit power and outweigh the downs.

You say it'll loose power and it's not worth his time. Nothing says it has to exit at the rear or out the sides, it could end underneath the car, in the wheelwells, right after the headers or wherever he chooses.

I'm just not convinced that cooling of the exhaust is going to lead to significant performance losses and if that's my opinion so be it.

 

I never said that I really wanted duals. I thought it would be a neat idea. I don't know it I mentioned it earlier but I am putting in a 3.1 with a 260H cam and ported heads/manifolds. If it won't make a difference then I won't do it. I am asking the question to get an idea of what would be the effects, if I did get duals then it would be a few months after the new motor and a nice tune, so it wouldn't really be till the end of the year/early next year till I would get them if I did. If I did get duals and go with sidepipes I would get a quieter muffler, I know it will be loud and sound like poo with glasspacks.

From what I am reading the duals would give me little power if any at all and side pipes would be better. I may not go with it. BTW the y-pipe on the car is from pacesetter so it is an actual y-pipe. What I may do it something like Blue1989RS suggested. Run duals till about mid car then go into a single pipe out the back. I could use a 2 into 1 muffler if they exist. Run 2 1/4" exhaust then into 2 1/2" or 3". So now I think true duals are out after thinking about it. The setup on the car now is great for a stock motor. I just didn't know if I would see more benefits from the cam and heads with duals. This isn't going to be a racecar, just a fun street car that is fun to drive around.

 

Its all good man. Just have fun with it. People can argue all day about what they think you should do. When it comes down to it, you'll do whats convienent or affordable. Be sure to post what you decide on, sounds like you'll do something cool regardless!

 

Their arguing is what made me decide to probably not go with duals. It sounds like that going duals won't give me any benefits. And if they did then they would be very mimimal.

 

I have glasspacks with downturns on either side of the framerails, right under the seats. Sounds mean without being too obnoxious, runs like open headers and has about the same clearance as the cat did. Many companies make 2 into 1 mufflers. Do you plan on running a cat?

 

I have one on my car right now. I got a Magnaflow on a few months ago without a cat and it was loud. I like a louder car but not abnoxious. This was rediculous for me and the rasp was bad. I put the highflow cat on to quiet it down a little and it took alot of the rasp out. Now there isn't much at all. I'm pretty happy with the setup I have right now. I'll change it after the new motor so that it can breathe a little more. I don't know if I will go with cats or not. I'll get the new exhaust put on with the 2 into 1 muffler and decide after a couple of days to decide if I like it or not.

 

It will affect o2 senor placement alot. Is yours a 1 wire or 3 wire sensor? 1 wire you'll want near the cat because they don't have a heating coil, 3 wire do so you want it further away to avoid overheating it and getting incorrect readings.

 

Its one wire. I used to not have a cat for a while. I'll have the shop put it in somewhere where it is now. The thing about finding the right muffler is finding one that is reversable. I know that a Flowmaster is out because they are chambered. I know that a Magnaflow will work but I am wondering about getting a Summit muffler since they are so much cheaper and are pretty much the same thing.

Found an Edelbrock muffler that is the right size and for a good price. Magnaflow has the right size also but only in their polished muffle and is some $225. Too much for me.