Is it possible to make a true dual exhaust on the fiero I'll do whatever is possible to make it happen a buddy told me to cut out the trunk well to give more space for the exhaust pipes I plan on using the stock exhaust for the right side so pretty much just gotta make a custom bends for the left side. I got 2 summit glasspacks that plan on using for the build for dirt cheap they have a 2 inch in diameter and a 2 in outer diameter also got a cat delete pipe.
[This message has been edited by pontiacfierokid1985 (edited 01-11-2011).]
Uh...having 2 completely different exhaust setups for each header isn't good.
There is absolutely no reason to have true duals in your Fiero IMO...make sure your engine will actually benefit first. True duals are almost always a good thing, but seldom enough of a good thing to be worth doing.
If you have a stock engine, then there really is no need whatsoever, and it might actually HURT performance.
Back when I meddled in software development, I commented several times that "You could probably install Linux on a blender, but that doesn't mean there's any reason to install Linux on a blender."
Now, if you have a boosted engine, a high revving V8, or some other monstrosity in your engine bay, it might (Emphasis on might) be worth it.
[This message has been edited by MadDanceSkillz (edited 01-11-2011).]
Well it is a stock 2.8 at the moment I'm just waiting for the clutch to burn completely out then that's when I'm gonna do my 3800 sc swap but I wanted to put a true dual on that setup if it is even possible cause I know that the 3800 is alot bigger an all looks like a really tight fit an all but I know it can be done the 3800 swap at least lol
Well it is a stock 2.8 at the moment I'm just waiting for the clutch to burn completely out then that's when I'm gonna do my 3800 sc swap but I wanted to put a true dual on that setup if it is even possible cause I know that the 3800 is alot bigger an all looks like a really tight fit an all but I know it can be done the 3800 swap at least lol
No reason to do duals on a 2.8l or 3800SC.
Duals are becoming synomous with cold air intakes for HP increase, seems like. My uncle is paying about 600 bucks to have duals put on his 93 Prelude with a Vtec, is convinced he's going to "pick up 30 ponies". He also thinks that duals on a 4 cylinder are a good idea though, so don't listen to him
I have built a couple different exhausts for a 3800 SC Fiero. The first was a very free flowing 3" system. Although it was not a Dual setup, it flowed very well - in fact too well. Now if you were building a 3800 SC with a lot of boost (smallest pulley) and had a bunch of mods to the heads, cam, intake, etc. Or a big turbo then yes - you would want it to flow. With the mild mods we have on this one though, it actually benefited by chokng it down a little. The latest setup is directly from the factory manifold dump into a stock Fiero 2.8 muffler then out to the standard dual tips. WIth the setup we gained noticable bottom end grunt and have seriously yet to find the top end of the car due to the car getting unstable at around 127 mph via a GPS unit. The 2.8 will not benifit from anything more than stock. The only gain would be sound? Maybe? It might sound worse. In fact I would bet you would loose some performance. Plus the cost to do it is a waste. Money better spent on other things.
I could see an improvement for the stock 2.8 since it does not need a cross pipe to scavenge and equalize uneven pulses if the piping were correctly sized
[This message has been edited by Erik (edited 01-12-2011).]
I could see an improvement for the stock 2.8 since it does not need a cross pipe to scavenge and equalize uneven pulses if the piping were correctly sized
I doubt that you will any improvement over stock with duals,; whereas the exhaust eyetem from the down pipe aft id not a problem. The headers and Y pipe are another story altogether. The stock setup is an awful design from ever aspect aside from how it looks and the fact that it is low enough to fit under near any hood GM cared to stuff it, and therein lies the reason to why it sucks.
I did allot of research into v6 exhaust design, and I found out that any sequentially timed 6 cylinder engine needs the primary pipes equal length. It then needs a collector which is 15x the swept area of a cylinder. In effect, the engines will run best with 32-36" pipes, and no further exhaust. The scavenging is the most important element so you need anywhere from a 1.25" pipe to a 1.5" pipe.
For this reason, Francis T is correct. past the headers it doesn't really matter what you have once you've achieved the 15x formula.
I wanted true duals and I have them on the car. (34x1.5" mandrel) I have not dyno'd them yet but I can tell you that the low end torque is enhanced and the engine wants to pull well past 6,000 rpm. I don't have the gonads to see what it can really do because the engine is worn. When the new motor goes in, it will go to the dyno with the headers.
The biggest problem with true duals is the lack of space on the rear bank. I did not want to cut the trunk and I ended up using 3" shorty mufflers as collectors into Spintech 12"x7" mufflers that Spintech fabricated up for me.
If you were willing to cut the trunk, I think a 2-inlet 2-outlet Magnaflow under the trunk would do the job really well.
Remember that 30+" primaries are really loud. Unbelievably loud. Neighbourhood trouble loud. You have to suppress them very well or pick up the heat for them.
One year at the Fiero Factory swap meet there was a Fiero with a V8 (SBC) and true dual exhaust. It sounded really sweet to stand behind it while it was idling. True stereo exhaust sound.
Duals are becoming synomous with cold air intakes for HP increase, seems like. My uncle is paying about 600 bucks to have duals put on his 93 Prelude with a Vtec, is convinced he's going to "pick up 30 ponies". He also thinks that duals on a 4 cylinder are a good idea though, so don't listen to him
I did allot of research into v6 exhaust design, and I found out that any sequentially timed 6 cylinder engine needs the primary pipes equal length. It then needs a collector which is 15x the swept area of a cylinder. In effect, the engines will run best with 32-36" pipes, and no further exhaust. The scavenging is the most important element so you need anywhere from a 1.25" pipe to a 1.5" pipe.
Arn
What research led you to this conclusion?
quote
Originally posted by ericjon262:
even fire motors won't benefit from a crossover pipe.
If used at a specific location to deliberately change the impedance of the system (IE, at the ends of the collectors), I don't see why an X-pipe *wouldn't* benefit an engine with even-fire banks.
------------------ I may have a green bar, but I'm not a nice guy. Deal with it and I'll give you good info.
IMO, it is highly debatable whether or not a true dual exhaust will produce much or any benefit on a V6 engine. If all the pipes are correctly sized the effort and cost will probably not be worth the return. Let me re-phrase this. True dual exhaust in a Fiero is possible but no one has proven that it is any better than a quality properly sized single pipe system.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 11-09-2012).]
IMO, it is highly debatable whether or not a true dual exhaust will produce much or any benefit on a V6 engine. If all the pipes are correctly sized the effort and cost will probably not be worth the return.
If used at a specific location to deliberately change the impedance of the system (IE, at the ends of the collectors), I don't see why an X-pipe *wouldn't* benefit an engine with even-fire banks.
what your describing sounds more like a so called "exhaust termination box". I don't really lump those into the same category as a crossover pipe, as the don't really do the same thing, a crossover is typically installed on a V8 to allow crowding (pressure buildups) to share the opposite bank's pipe. this crowding occurs when cylinders 5+7 and 4+8 on a SBC fire (firing order 18436572) because they are on the same bank multiple pulses arrive at a closer interval than on a even fire motor like the stock V6. on the stock V6, the firing takes place bank to bank at even intervals, so there is no crowding, and thus no need for a crossover or balance pipe.
quote
Originally posted by Will:
Debate is mostly irrelevant without test data.
This is also very true.
------------------ there's a Group on 60degreeV6.com for us 660 Fiero owners!
what your describing sounds more like a so called "exhaust termination box". I don't really lump those into the same category as a crossover pipe, as the don't really do the same thing, a crossover is typically installed on a V8 to allow crowding (pressure buildups) to share the opposite bank's pipe. this crowding occurs when cylinders 5+7 and 4+8 on a SBC fire (firing order 18436572) because they are on the same bank multiple pulses arrive at a closer interval than on a even fire motor like the stock V6. on the stock V6, the firing takes place bank to bank at even intervals, so there is no crowding, and thus no need for a crossover or balance pipe.
In order to do its job, a collector needs to have a specific length. The features that define that length are the merge point of the tubes and something at the other end which provides a change of impedance to cause the pressure pulses to reflect back up the collector and primaries. The collector being open to the atmosphere does this. The collector dumping into a large enough enclosed volume ("termination box") also does it. I've been wondering if the impedance transition associated with an X or merge pipe would be enough to assure that the collector works correctly.
"crowding" isn't what requires the termination box, but crowding *does* affect the diameter of collector that works best... A V8 will work best with a certain collector size with per-bank headers, but will work best with a smaller collector with 180 degree headers, because the collectors don't have to deal with the sequential cylinders on each bank.
[This message has been edited by Will (edited 11-09-2012).]
well to answer the op question yes it can be done. joesfiero on the forum has true duels in hif 3800sc swap. i know JimmyS new build car is going to have them too. now whether or not they are worth it i have no idea.
only reason they have duals and a crossover be it an "H" or an "X" is space.. not many cars can house a 3.5"-4" pipe under the car.. true duals with no crossover sound sweet.. no changing that.. but from a power standpoint.. a single pipe that got an ideal crosssection is better than duals allmost every time..
oh and a 3-4" pipe is mighty loud
[This message has been edited by E.Furgal (edited 11-09-2012).]
Originally posted by E.Furgal: only reason they have duals and a crossover be it an "H" or an "X" is space.. not many cars can house a 3.5"-4" pipe under the car.. true duals with no crossover sound sweet.. no changing that.. but from a power standpoint.. a single pipe that got an ideal crosssection is better than duals allmost every time..
oh and a 3-4" pipe is mighty loud
That is nonsense. The reason the new Vettes have the X pipe is because they don't have 180 degree headers, because of space. It has nothing to do with 3.5-4" pipe; especially at the length the exhaust is. Having too large a diameter of exhaust pipe is just as bad as having too small an exhaust pipe, and in some cases, actually worse. Too large a pipe won't be able to maintain the exhaust temp and pressures all the way down the line, which are needed to properly evacuate the gases.
An optimal exhaust set up will be tuned to match the demands of the engine based on RPM range, camshaft design, heads, and firing pulses. Putting bigger pipes on isn't always a good idea.
There are no "true dual exhaust" anymore. Not since they discovered that putting a cross pipe in the middle of the system gives better performance.
yup, my Corvette has an X pipe, I can't say that I know anyone with a C5 or C6 with dual exhaust, there is certainly room for dual, after all, the exhaust is dual everywhere EXCEPT the X pipe
[This message has been edited by ZaraSpOOk (edited 11-10-2012).]
i have true duels on my 4.9, when i pulle dthe engine from the eldorado it never had a crossover to begin with so i ws left with little choice (as at the time i didnt know they have one) so i made duel exhaust and what a pain in the butt. trying to fit the pipe under the oil pan on the passenger side and then getting the pipe to fit with the muffler just behind the trunk on the drivers side..... if i had to id never do it that way again.
Having too large a diameter of exhaust pipe is just as bad as having too small an exhaust pipe, and in some cases, actually worse. Too large a pipe won't be able to maintain the exhaust temp and pressures all the way down the line, which are needed to properly evacuate the gases.
This only applies up to the end of the collector... If the collector is properly terminated, then the only thing the rest of the exhaust has to do is not restrict the outflow from the termination, be it box, X-pipe or something else.
ZR1 and ZO6 Corvettes use the same cat-back exhaust, despite a difference of 140 HP...
Mostly correct. What matters is the length of the primaries to the collector. In a v6 sequential engine the primaries should be equal length, not longer than 36". The collector is another story. There are a number of types. Essentially though, the v6 would operate just fine without a tail pipe, collector or resonator, provided those primaries were correct. So the point is to make sure that when the gases hit the collector, there is no impediment for the gases to exit. Generally though, you need to keep the gases hot, because hot gases move faster than cold, and, you need to ensure the pulses don't slow down. So there is good cause to consider the tail pipe side well. I totally agree a single can be as efficient as true duals. My problem was designing a Y system using 32" primaries. It was to big a headache for me so I just went to true duals.
Well designed, correctly sized collectors are always beneficial.
The whole point of terminating the colectors is to decouple the rest of the system to allow the collectors to work optimally. which means as if they were dumping to open air. Downstream of the termination, there shouldn't enough pulse or velocity energy to be worth worrying about, as the whole point of the header system is to use as much of the exhaust energy as possible to scavenge and kick start the pulse/velocity system on the intake side.
Here what I made up for my 4.9 Swap a number of years ago. I reused most of the Stock Exhaust Pipe for the firewall side. Just picked up 2" pips and U's for what I was short. I started out with about 1 foot of the stock caddy pipes with the O2 bungs in place already, Those are not glasspacks but Performance Mufflers from Jones Exhaust that happen to look like glasspacks. Enjoy the Pic's
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**************************************** 88 Formula CJB Arrived Finally. #689 of 1252 Time to start Working TONY! There are Two kinds of Fiero's : Notchies and Donors!
I think the only reason why you might want true duals is for the sound. I would be willing to bet that it would actually sound pretty cool... but probably not worth the cost. I've always liked true duals because each-side sounds a little bit different... the "burble" is off-synch between the two, and it "sounds" cool. Even with an H-pipe, I've been able to see a difference between the various sides (like on my Crown Victoria).
I think the only reason why you might want true duals is for the sound. I would be willing to bet that it would actually sound pretty cool... but probably not worth the cost. I've always liked true duals because each-side sounds a little bit different... the "burble" is off-synch between the two, and it "sounds" cool. Even with an H-pipe, I've been able to see a difference between the various sides (like on my Crown Victoria).
Well 2 pipes of correct diameter will flow better then one. With the 4.9 I felt that running the Stock 2.8 pipes for each bank would be good Plus at the time I got both mufflers for the same cost as a Flowmaster 70 or 80 that most people run. I loved the sound and will be duplicating this set up on my current swap :P
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**************************************** 88 Formula CJB Arrived Finally. #689 of 1252 Time to start Working TONY! There are Two kinds of Fiero's : Notchies and Donors!
Well 2 pipes of correct diameter will flow better then one. With the 4.9 I felt that running the Stock 2.8 pipes for each bank would be good Plus at the time I got both mufflers for the same cost as a Flowmaster 70 or 80 that most people run. I loved the sound and will be duplicating this set up on my current swap :P
Well, I really just meant in terms of a stock Fiero V6. I think duals on a lot of cars make perfect sense. But there was a lot of posts above saying it would be a waste, so I was simply saying that if he'd want it still, it would be because of the sound... love the sound. There's definitely nothing wrong with having great sound!!! heheh...
Originally posted by 82-T/A [At Work]: Well, I really just meant in terms of a stock Fiero V6. I think duals on a lot of cars make perfect sense. But there was a lot of posts above saying it would be a waste, so I was simply saying that if he'd want it still, it would be because of the sound... love the sound. There's definitely nothing wrong with having great sound!!! heheh...
But you're not going to get the same sound as that Lamborghini, by just dumping each bank out of a separate pipe, with a 2.8 V6. There's a big difference between a low-displacement, high-revving V12, than there is with the far inferior Fiero 2.8. And that Lambo doesn't just have a pipe hanging off each bank either. Here's a picture of the monstrosity of an exhaust system, installed in that Countach you posted the video of:
Getting that sort of sound out of a Fiero 2.8 is a lot more work than simply dumping each bank out through totally separate pipes.
But you're not going to get the same sound as that Lamborghini, by just dumping each bank out of a separate pipe, with a 2.8 V6. There's a big difference between a low-displacement, high-revving V12, than there is with the far inferior Fiero 2.8. And that Lambo doesn't just have a pipe hanging off each bank either. Here's a picture of the monstrosity of an exhaust system, installed in that Countach you posted the video of:
Getting that sort of sound out of a Fiero 2.8 is a lot more work than simply dumping each bank out through totally separate pipes.
I love you man... but I'm pretty sure I wasn't suggesting anywhere that a Fiero 2.8 would produce that kind of sound with dual exhuast.
Maybe this would have been a better video to link to, in order to show enthusiasm for exhuast sound:
IMO, the engine needs to be under load to get a proper idea of what the exhaust system actually sounds like.
There's actually another video of the same car as it's driving away, and you're right... it sounds totally different... VERY cool. It really brings out the harmonics that the 60 degree is capable of.
(At least with a V8.)
