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True dual exhaust is it possible ??? by pontiacfierokid1985
Started on: 01-11-2011 11:09 PM
Replies: 193 (5744 views)
Last post by: Hairold on 07-19-2013 01:00 PM
dobey
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Report this Post02-03-2013 04:52 PM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 82-T/A [At Work]:
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:


Your post (and inclusion of that video) seemed to suggest one could get such a sound out of doing true duals, though. I thought it would be good to clarify it won't, as if that's the sound the OP is trying to go for, and thinks true duals will get him there, he'll be very upset after spending $$$ to have true duals made up for his Fiero, and having it sound horrible.

The same with that Taiwanese Fiero. It's a tune custom exhaust setup, and while it sounds great, plain true duals won't get one there.

It may not be what you're trying to say, but your post still implies that true duals will get a sound similar to that. I don't know what sound or performance the OP was hoping to get out of true duals, but that sound won't be the result if it's done.
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Report this Post02-04-2013 02:03 PM Click Here to See the Profile for FieroGT42Click Here to Email FieroGT42Send a Private Message to FieroGT42Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by MadDanceSkillz:
He also thinks that duals on a 4 cylinder are a good idea though, so don't listen to him


True duals on a Subaru or Saab Sonett 4 cyl would be an excellent idea.
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Report this Post02-04-2013 03:22 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by FieroGT42:

True duals on a... Saab Sonett 4 cyl would be an excellent idea.


Listen to the beautiful sound of this Sonett V4 engine... with true duals.



Need to put dual exhaust on the '84 duke now!

[This message has been edited by Patrick (edited 02-04-2013).]

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82-T/A [At Work]
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Report this Post02-04-2013 05:39 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by dobey:


Your post (and inclusion of that video) seemed to suggest one could get such a sound out of doing true duals, though. I thought it would be good to clarify it won't, as if that's the sound the OP is trying to go for, and thinks true duals will get him there, he'll be very upset after spending $$$ to have true duals made up for his Fiero, and having it sound horrible.

The same with that Taiwanese Fiero. It's a tune custom exhaust setup, and while it sounds great, plain true duals won't get one there.

It may not be what you're trying to say, but your post still implies that true duals will get a sound similar to that. I don't know what sound or performance the OP was hoping to get out of true duals, but that sound won't be the result if it's done.


If I could easily find a smiley that had a slap forehead, I would post it.

I'm pretty sure everyone here knew that a new exhaust system wouldn't make their V6 Fiero sound like a Lamborghini Countache.
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Report this Post02-04-2013 06:06 PM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 82-T/A [At Work]:
If I could easily find a smiley that had a slap forehead, I would post it.

I'm pretty sure everyone here knew that a new exhaust system wouldn't make their V6 Fiero sound like a Lamborghini Countache.


This one?

But look through the history of exhaust related posts on the forum, and you would be surprised.
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Report this Post02-05-2013 12:20 PM Click Here to See the Profile for Marvin McInnisClick Here to visit Marvin McInnis's HomePageSend a Private Message to Marvin McInnisEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by pontiacfierokid1985:

Is it possible to make a true dual exhaust on the fiero I'll do whatever is possible to make it happen ...



Why? What is your objective? You've never told us that, and it will affect the answer. Given enough time and money, almost anything is possible ... but the results may not justify the effort.


 
quote
Originally posted by FFIEROFRED:

1. don't forget about the 02 senser. It has to read both banks



Exactly! Done properly, independent dual exhaust systems will require two separate O2 sensors ... and an ECM (plus programming) capable of handling them. FWIW, the trend in modern OEM engine fuel system design is headed toward one O2 sensor per cylinder, for optimum mixture control and minimum exhaust emissions.

[This message has been edited by Marvin McInnis (edited 02-05-2013).]

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Report this Post02-05-2013 01:07 PM Click Here to See the Profile for KentoClick Here to Email KentoSend a Private Message to KentoEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
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Originally posted by Marvin McInnis:
. FWIW, the trend in modern engine fuel system design is headed toward one O2 sensor per cylinder, for optimum mixture control and minimum exhaust emissions.



WOW!! Talk about an Octopus of wiring. Imagine having 4, 6, or even 8 A/F gauges on your dash!!!!

That would be a way to get the most efficient mixture all the time.

------------------

****************************************

88 Formula CJB Arrived Finally. #689 of 1252
Time to start Working TONY!
There are Two kinds of Fiero's : Notchies and Donors!

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Report this Post06-12-2013 08:26 PM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
Where angels fear to tread ... When I commenced the quest to upgrade the engine to 3.4 660 and 4T60 tranny, I wanted to see if there was a better exhaust setup than the stock available. After alot of browsing, I felt I'd like to try a true dual equal length system. The short of it is, I bought Arns85GT headers with intent to use them. However, the trunk side would not fit with the 4T60 so elected to start from scratch. With tubing and collector and V-ring/clamp parts from Columbia River Mandrel Bending and Magnaflow mufflers, two helpers and I fabricated the exhaust system the first weekend of June. They are now at Finish Line Coatings for ceramic coating. Will they be as hoped? Only time will tell. Photos here: http://craigphoto.smugmug.c...2571895831&k=LQ7Rfvh
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Report this Post06-13-2013 03:55 PM Click Here to See the Profile for CarverTooClick Here to Email CarverTooSend a Private Message to CarverTooEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Asterix:

Where angels fear to tread ... When I commenced the quest to upgrade the engine to 3.4 660 and 4T60 tranny, I wanted to see if there was a better exhaust setup than the stock available. After alot of browsing, I felt I'd like to try a true dual equal length system. The short of it is, I bought Arns85GT headers with intent to use them. However, the trunk side would not fit with the 4T60 so elected to start from scratch. With tubing and collector and V-ring/clamp parts from Columbia River Mandrel Bending and Magnaflow mufflers, two helpers and I fabricated the exhaust system the first weekend of June. They are now at Finish Line Coatings for ceramic coating. Will they be as hoped? Only time will tell. Photos here: http://craigphoto.smugmug.c...2571895831&k=LQ7Rfvh


Beautiful work! What are you doing about the O2 sensor(s)?
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Report this Post06-14-2013 01:38 AM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
Fiero 660 has provision for only one sensor, would require extensive electronics mods to add a second one. Engine builder said, because of "consistency" of new parts from one side to the other, one should be fine. It is going into the collector just ahead of the muffler on the firewall side.
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Report this Post06-14-2013 09:01 AM Click Here to See the Profile for Arns85GTClick Here to Email Arns85GTSend a Private Message to Arns85GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Asterix:

http://craigphoto.smugmug.c...2571895831&k=LQ7Rfvh


What a great job! I hope you can find a stick shift Fiero for the other set. You obviously have taken my idea to a whole new level. Well done.

Here is my current system. Just a little different, and not true duals.



------------------

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Report this Post06-14-2013 11:11 AM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Arns85GT:


What a great job! I hope you can find a stick shift Fiero for the other set. You obviously have taken my idea to a whole new level. Well done.

Here is my current system. Just a little different, and not true duals.




Wow what is that manifold from?
Also why not Y bend the joint instead of a T?
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Arns85GT
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Report this Post06-14-2013 03:10 PM Click Here to See the Profile for Arns85GTClick Here to Email Arns85GTSend a Private Message to Arns85GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
The manifolds are stock '92 deVilles.

I didn't Y due to two reasons.

First, the Y is harder to fab up than what I did and I needed every inch of space to get my CATs in and still do a nice bend to the mufflers.

Second, the T is actually pretty free flowing. It divides the sound but does not detract from the flow.

It is constructed like this



You see there is no net loss of area, and the flow naturally splits. Hope this explains a ltitle.

Arn

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Darth Fiero
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Report this Post06-14-2013 03:40 PM Click Here to See the Profile for Darth FieroClick Here to visit Darth Fiero's HomePageClick Here to Email Darth FieroSend a Private Message to Darth FieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
A few years ago I did some exhaust work on a friend's 1957 Chevy that had a Ramjet PFI 350 SBC in. When he originally had the car built, he used long tube headers and had a shop fab up true dual exhaust out of 2.5" stainless pipe running to two Borla mufflers. There was quite a long run of straight pipe between the headers and the mufflers. The shop did NOT install an X or H pipe between the two exhaust banks so they were not tied together at all.

The car ran ok with this exhaust configuration but it sounded like it had cherry bombs for mufflers (raspy/snapping sound) and it lacked low end and some mid-range performance (at least that was what it felt like to me when I drove it). I convinced my friend we should at least install an H-pipe if nothing else. He did not really have the room to run a nice X pipe due to the lack of space under the car with the transmission he was using. So I installed an H-pipe for him.

Upon starting up the engine with the new H-pipe installed, we immediately could tell a difference in the exhaust note. It was much smoother and had lost the rasp/snap that was common before. Upon driving the car, we discovered the low RPM performance had increased greatly and it also picked up some mid-range performance as well. Top end performance seemed to be unaffected and was still as good as it was before. Not only was the rasp note gone, but it just sounded stronger. Can't say whether or not it got any quieter or louder - it just sounded altogether different.

The important thing is that performance increased without losing it anywhere and he also reported back to me that the car gained some fuel economy in the process as well.

It should be noted that the headers he was using did NOT have equal length tubes nor made using any special design for the SBC he had.

As far as the topic at hand is concerned, you aren't going to get ANY performance gains by running true-duals without any kind of connecting X or H pipe unless you have a very good set of headers and exhaust system that has been properly designed and engineered for the engine you are using. Now, having said that, the stock Fiero 2.8 exhaust system leaves a lot to be desired. Everything from the stock manifolds to the y-pipe to the muffler are pretty much undersized and highly restrictive even for the stock 2.8. But the stock manifolds are the biggest restriction and should be the first thing you change out if you are going to be making any modifications whatsoever.

Concerning any engine swap, true duals will give you pretty much no benefit at all since it isn't practical to run the set of specially designed headers you need for whatever engine you are using. The Fiero's engine bay just does not give you the room to do this. Therefore, you should run a system that ties both banks together at some point (best to use an X pipe) or if necessary, both and be Y'd together to run thru 1 pipe - but make sure you use large enough tubing, mandrel bends, and low restriction components (mufflers, cats, etc) if you want maximum performance.





(And yes, after I took this picture I did convince my friend to let me build him a custom induction system out of polished stainless and mount the air filter out in front of the core support so the engine could breathe cold air as opposed to heated radiator air as it did with the air filter mounted directly to the throttle body. The addition of the cold air induction system increased performance everywhere - especially in the upper RPMs).

-ryan

------------------
OVERKILL IS UNDERRATED

Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

[This message has been edited by Darth Fiero (edited 06-14-2013).]

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Arns85GT
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Report this Post06-14-2013 05:40 PM Click Here to See the Profile for Arns85GTClick Here to Email Arns85GTSend a Private Message to Arns85GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
If it is a sequentially fired v6 like the Fiero, true duals give you a very nice kick in the pants in the working low range, as well as high end breathing.

The secret is to make the primaries 32" to 36" depending on the engine specs and all equal length into the appropriate collector.

There is no cross over needed. Unlike the V8's which have kind of a scrambled firing sequence and need a different setup.

BTW a long run of pipe from the headers to the muffler is a real good way to cross up the exhaust pulses. This can be largely eliminated with a good H or X system.

Arn
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Report this Post06-14-2013 09:48 PM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
Arn, thanks for the clarification/support for what we fabricated. Having run your comments past several who are savvy about the difference between sequential (like the 660) and V8 engines (and before I settled on doing the "true duals"), I got "thumbs up" to continue the quest. After the fabrication was done, I showed the headers to a friend who has set records at Bonneville and he concurred they were done correctly. As for intake, I had the throttle body and intake runner opened up. Time will tell and, good or bad, I will post the results (no fish stories because I don't fish ... ).

[This message has been edited by Asterix (edited 06-14-2013).]

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Report this Post06-15-2013 10:29 AM Click Here to See the Profile for aaronkochClick Here to Email aaronkochSend a Private Message to aaronkochEdit/Delete MessageReply w/QuoteDirect Link to This Post
Asterix, not sure where in the US you live, but Damian (Donesky Racing) in the Vancouver, WA area is currently building these:





Pure, equal length, true dual, tuned primary exhaust love.


------------------


Build thread for my 88 + 3800NA swap

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Report this Post06-15-2013 02:58 PM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
That is me in the photo. Johnny Spiva (www.polybushings.com) and I fabricated these and Damien did the majority of the final welding. The parts are currently at Finish Line Coatings (Russ Meeks, RM Engineering) in Milwaukie, Oregon, for ceramic coating. FWIW, Russ was our Tech Editor when I was Editor of Street Rod Magazine so I've know him for over 40 years. Damien is doing the engine build for me. I might also mention that Spiva suggested to use 1.5" foam pipe insulation to help mock up the primary pipes. I bought a length and cut a piece to 34" and that scheme worked perfectly for working out where each primary needed to be routed.

More photos are at: http://craigphoto.smugmug.c...2571895831&k=LQ7Rfvh

[This message has been edited by Asterix (edited 06-15-2013).]

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Report this Post06-19-2013 07:57 PM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
I picked up the headers and mufflers today after having them ceramic coated at Finish Line Coatings, Milwaukie, Oregon. Added a photo at this link:
http://craigphoto.smugmug.c...2585463946&k=xvR25gr

More photos will follow when these are installed on the engine. And, yay, the aluminum gas tank (via Joe Solerno) was installed yesterday.

[This message has been edited by Asterix (edited 06-19-2013).]

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Will
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Report this Post06-19-2013 10:43 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Arns85GT:

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.


 
quote
Originally posted by Arns85GT:

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.

Arn


 
quote
Originally posted by Arns85GT:

If it is a sequentially fired v6 like the Fiero, true duals give you a very nice kick in the pants in the working low range, as well as high end breathing.

The secret is to make the primaries 32" to 36" depending on the engine specs and all equal length into the appropriate collector.

There is no cross over needed. Unlike the V8's which have kind of a scrambled firing sequence and need a different setup.

BTW a long run of pipe from the headers to the muffler is a real good way to cross up the exhaust pulses. This can be largely eliminated with a good H or X system.

Arn


You keep throwing those numbers around without any basis or justification. You've never mentioned exhaust cam duration or desired tuning RPM, for example.

The purpose of the X-pipe is related to impedance. I'd like to try both configs on an engine with even fire banks. I suspect that when placed at the right location in the system, the X-pipe benefits an engine with even-fire banks as well.
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Report this Post06-20-2013 06:35 AM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
You keep throwing those numbers around without any basis or justification. You've never mentioned exhaust cam duration or desired tuning RPM, for example.

The purpose of the X-pipe is related to impedance. I'd like to try both configs on an engine with even fire banks. I suspect that when placed at the right location in the system, the X-pipe benefits an engine with even-fire banks as well.


Feel free to try whatever you like, and good luck finding a place to put the X-pipe!

As for my installation, based on the info from Arn plus input from a friend that has been building performance engines for over 40 years and who holds several records at Bonneville, I then had TLAR Engineering do the final design. All three agreed there was no need for any H- or X-pipe.
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Report this Post06-20-2013 07:52 AM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
Conventional wisdom is... well... conventional

TLAR's AWD Del Slo project looks interesting, but they're no Burns Stainless.

[This message has been edited by Will (edited 06-20-2013).]

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Report this Post06-20-2013 09:34 AM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well, it may not look like a Harley, or be as fast as one, but it'll at least have the same sort of rumble, if a bit quieter thanks to the mufflers and length of the exhaust.

If you want to sacrifice some efficiency and performance for that sound, it's certainly a choice you can make. But Will is absolutely correct in his statement that there is no justification for the primary lengths or mention of camshaft design, or desired RPM range.
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Report this Post06-20-2013 08:16 PM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
Oh, too funny! Not the same "TLAR Engineering" ... I've been using that "name" as a "joke" for 30 years for when I sketch a design (like a wing on the garage floor with chalk) and say "That Looks About Right" and make it. Had no idea there was a "real" TLAR Engineering. So, no, that TLAR was not who did the "engineering" for my headers. ROFLOL!

As for this build: it commenced over a year ago because I wanted an overdrive trans, then selected the GM 4T60 as recommended by Fieroking. Shorty after, I was introduced to thedrue who is only a few miles from me. After a session or so with him, I elected to do a complete engine/trans/88-cradle build rather than just swap the trans into our stock 86GT. The entire build was planned and spec'd along with the info (including math formulas) I got from Arns85GT about the "true-dual" headers. The engine-spec info was then provided to a company that does custom cams seeking their input, including "best combo of economy and performance"; I got a custom-ground cam from them based on their recommendation. So, IMHO, all the "patter" about "it won't work" and "it needs a crossover" and "equal length doesn't cut it" and the "cam" comments are wholly without merit. Am I right or wrong? Fact is, I don't care because I took the time to consult with people who have "been there done that" before I decided to proceed.

I do, however, regret that I failed to realize I shoulda-coulda gotten three Harley V-twins, modified the cases so a single crankshaft could be used, then mate that to a DAF continuously-variable trans. Life has it's hazards!

[This message has been edited by Asterix (edited 06-20-2013).]

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Report this Post06-20-2013 10:12 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
"Works" and "Works best" are very different ideas.
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Report this Post06-21-2013 12:59 AM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
Will, I've long held to a "maxim" ... "If you think something is wrong, don't do it." So, if you don't like what I've done, don't do it. To paraphrase your comment: an "opinion" and a "worthless opinion" are very different ...

[This message has been edited by Asterix (edited 06-21-2013).]

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Report this Post06-21-2013 09:52 AM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Asterix:
So, IMHO, all the "patter" about "it won't work" and "it needs a crossover" and "equal length doesn't cut it" and the "cam" comments are wholly without merit. Am I right or wrong? Fact is, I don't care because I took the time to consult with people who have "been there done that" before I decided to proceed.


You are wrong. The comments are with plenty of merit. Making the assumption that only the people you talked to have "been there done that" however, is without merit. The only interesting thing about an equal length true dual system in a Fiero, is that someone managed to make it fit. Your disagreement with facts, doesn't suddenly make those facts into opinions. Nor does your condescending of them.

I don't know why you chose (or were coerced into) a true dual setup for your car. It's really not relevant to the thread. The topic of the thread is "is it possible to do true duals in a Fiero?" and the answer is obviously yes.

And don't say "I don't care" because it's quite obvious you do care. You spent time and money to build that system, and your feelings are hurt if anyone tells you it's wrong, or not the best system you could build for your engine. You're taking the time to defend your choice, and those whom you consulted, by replying to the thread. So you obviously do care. But don't take it personally, as you seem to be, when someone tells you something else would be better for the car.

You've decided to do something a certain way. You disagree with others saying it's not the best. We get it. Leave it be, or partake in the conversation as to why it's not, and learn something, rather than trying to insult those you disagree with by attempting to condescend them.
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Report this Post06-21-2013 04:07 PM Click Here to See the Profile for aaronkochClick Here to Email aaronkochSend a Private Message to aaronkochEdit/Delete MessageReply w/QuoteDirect Link to This Post
Asterix,

I believe it will work beautifully, and the even pulses will sound heavenly. I got so much crap from "experts" when I elected to use flipped f-body manifolds on my 3800 swap to make it sound like a 60 degree v6 you wouldn't believe it. Math usually works, and in my case it did, as it will in yours. Even if it could slightly benefit from a crossover (I'm not convinced it would), what would the difference be on an even-pulse fired motor? About 1-2HP tops? In my book the glorious sound would outweigh that anyway.
I hope you make it to fiero fest this year in Richland, I really want to hear your ride!

Dobey, how's your swap coming along?

------------------


Build thread for my 88 + 3800NA swap

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Report this Post06-21-2013 05:38 PM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
aaronkoch:
Thanks for the kind comments. I can certainly identify with your "so much crap" experience. Unless something unforeseen prevents, I will be in Richland, had a great time there the last two years.

dobey:
 
quote
I don't know why you chose (or were coerced into) a true dual setup for your car. It's really not relevant to the thread. The topic of the thread is "is it possible to do true duals in a Fiero?" and the answer is obviously yes.


Nobody coerced me into doing anything. I chose to seek an alternative because the stock Fiero exhaust system is restrictive and would be especially so on the 3.4. The alternatives I found were either no longer available or offered no improvement over the stock system. My quest led me to this thread and, after consulting with several people, I elected to "go for it." And, since this thread is "is it possible ..." and that I chose to proceed, what we fabricated is directly and specifically relevant to this thread. I kinda sorta thought the intent of any thread was to provide facts and data about a subject, in this case being "true duals." So, how is what we built and why we built it not relevant to the thread? Please be specific.

 
quote
You've decided to do something a certain way. You disagree with others saying it's not the best. We get it. Leave it be, or partake in the conversation as to why it's not, and learn something, rather than trying to insult those you disagree with by attempting to condescend them.


Who is being insulting[interobang] Who is being condescending[interobang] Consider:

In what way is consulting with those who have "been there, done that" and "have experience" and are "performance engine builders" not relevant to my decision, and in what way is that not "learing something"? Please be specific.

In what way is a Harley V-twin exhaust system relevant to a 60-degree V-6 sequential-fire exhaust system? Please be specific, because these engines are so completely different (other than that they are reciprocating piston four-cycle internal combustion engines) that I question the thought process that brought that comparision to the table.

In what way is the need for H or X crossovers on a V-8 relevant to a 60-degree V-6 sequential-fire engine? Please be specific, because that issue was discussed earlier in the thread several times and was given due consideration when we planned the system we fabricated.

In what way are equal-length primaries not of any use? Please be specific, because there is a long-standing tradition of "bunch of bananas" equal-length extrator exhaust systems being used in performance engines. And directly relevant to equal-length is the length, as follows:

In what way is "primary length" not relevant to the design? Please be specific because the length chosen was based on mathematical formulas (and calculations) provided by Arn. (Also, the mufflers were chosen after consluting, by phone, with techs at MagnaFlow.)

In what way is the fact that the performance cam company was given engine-build specs along with the intended purpose for use of the engine not relevant? Please be specific because you and Will both mentioned "cam" as an issue.

What information in your and Will's posts have included anything, beyond your opinions, that are helpful to this thread or to what we fabricated? Please be specific, because, in my view, you are the ones who are being condescending. As I stated, if you don't like what we did, then don't do it. I note that aaronkoch asked how your swap was coming along . Would you be impressed if I commented that your swap was a bad idea without offering any specifics as to why? Probably not.

Hurt feelings[interobang] Unwarranted presumption on your part! You don't think what I chose to do is a good idea. I get it. Leave it be. And, as for "partake in the conversation as to why ..." is exactly why I've responded as I have, because you and Will have posted opinions that have no specific information, facts, or data to back up what you opine. In literary terminology, such opinions are classified as "glittering generalities." (And, "I don't care" means "I don't give weight to opinions that have no data to back them up.") So, what information have you provided that was helpful to me or this thread? Please be specific, because, in my view, nothing you or Will have said has been helpful or relevant.

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Report this Post06-21-2013 07:18 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
Arn hasn't posted any calculations to THIS thread. He's posted numbers without note to how they were derived... Not having insight into the derivation makes them as useless as political statistics.

You haven't posted dyno numbers, so we have no idea how well your system works. You also have no idea how well your system works compared to anything else. You seem to think that because you did what math you know and the system gets exhaust gas from the ports to the tailpipes, it must be optimal.

I'm the only one in this thread who takes collector length and diameter seriously. If you don't take those variables VERY seriously, I have serious doubts about the effectiveness of your research.
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Report this Post06-21-2013 08:31 PM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Arn hasn't posted any calculations to THIS thread. He's posted numbers without note to how they were derived...

Did you ask him for them? I did via PM and he emailed them to me after which we continued to communicate about the matter via email.

 
quote
Not having insight into the derivation makes them as useless as political statistics.

Insight comes with asking the right people the right questions.

 
quote
You haven't posted dyno numbers, so we have no idea how well your system works.

Duh Oh! Obviously there are no numbers! The build is not finished!

 
quote
You also have no idea how well your system works compared to anything else.

See above.

 
quote
You seem to think that because you did what math you know and the system gets exhaust gas from the ports to the tailpipes, it must be optimal.

What I "seem to think" is that it was worth a try after checking out all the options and consulting with others. And I have said several times (IF you had been paying attention) that I/we would not know until we had opportunity to do the real life testing.

 
quote
I'm the only one in this thread who takes collector length and diameter seriously.

That claim is so false it doesn't deserve a response.

 
quote
If you don't take those variables VERY seriously, I have serious doubts about the effectiveness of your research.

Go ahead and doubt all you want to. If it works or not is not on your dime, it is on mine. And, as I commented to dobey, I consider your comments to be irrelevant because you don't include anything to support your opinions, and condescending and arrogant because you seem to think you are the only one who has any expertise. In fact, I've never questioned your expertise or qualifications; I DO question that you make derogatory comments without any supporting evidence. I conclude you have paid no attention to what I've said (in condensed version), "Here is what we're doing, we think it will work so we are gonna give it a try. We will let you know how it works out." In short, if you want a courteous dialog, then be courteous. Otherwise, "give it a rest."

[This message has been edited by Asterix (edited 06-21-2013).]

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Report this Post06-21-2013 08:53 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Asterix:

Did you ask him for them?



Read the thread.

 
quote
Originally posted by Asterix:

That claim is so false it doesn't deserve a response.



Arn's talked up primaries but has barely said anything about collectors.

Edit: got mixed up about whose photos are whose.

Edit 2: You don't take collectors seriously. Yours are different lengths: http://craigphoto.smugmug.c...2571895831&k=LQ7Rfvh

[This message has been edited by Will (edited 06-22-2013).]

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Report this Post06-22-2013 09:08 AM Click Here to See the Profile for Arns85GTClick Here to Email Arns85GTSend a Private Message to Arns85GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Will:

Arn hasn't posted any calculations to THIS thread. He's posted numbers without note to how they were derived... Not having insight into the derivation makes them as useless as political statistics.

I'm the only one in this thread who takes collector length and diameter seriously. If you don't take those variables VERY seriously, I have serious doubts about the effectiveness of your research.


You really are trying to make enemies, aren't you? You haven't followed my build threads or you would know that I researched true duals for about a year before I built them. Have you built any for the Fiero? So far as I know, Asterix has taken my work and built on it better and is to be congratulated. The exhaust is designed independent of the intake, with the intention of evacuating the gases the fastest way possible, independent of the intake. The cam and cylinder are taken into account.

The calculations I used were from the book entitled SCIENTIFIC DESIGN OF EXHAUST& INTAKE SYSTEMS third edition. by Philip H Smith FI MechE MSAE, and John C. Morrison BSe PhD MI MechE It can be purchased on Amazon for about $30.

Here are the extracted calculations I used.





I did not deal with the collector, because if you do some reading on V6 racing and performance, you will soon realize that the collector recommended is pretty big. So big that you could, in theory, run the primaries without a collector and make really good power, but really noisy. Those 32" pipes act like trumpets.

The Fiero has very little room, so, with 2.5" pipe I deemed the collector requirements to be satisfied with the tail pipe system.

So, Will, show me you know what your are talking about and not just taking cheap shots.

Arn


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Report this Post06-22-2013 12:55 PM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Asterix:
So, what information have you provided that was helpful to me or this thread? Please be specific, because, in my view, nothing you or Will have said has been helpful or relevant.


Read the whole thread, and not just from the point at which you decided to hijack a thread that has been dead for months. The discussion in the thread already concluded that true dual exhaust was possible and feasible, in certain situations.

If you want to show off your build and discuss the specifics of your build, then start your own thread. And any argument you have made against any statement Will or I have made, is that "some other guy told me it will work." You haven't shown any specific data about your build either. The only thing you've said relevant or helpful to the original point of the thread so far, is your first post that brought this thread back from the dead, saying you were doing a true dual system. Everything else you've posted has just been overly defensive commentary. Stop taking every single word someone writes, so seriously, and personally. It's unhealthy. And practice some reading comprehension, so you don't go expanding a one liner that someone wrote about how your exhaust will sound/perform, into a novella.
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Report this Post06-22-2013 01:13 PM Click Here to See the Profile for aaronkochClick Here to Email aaronkochSend a Private Message to aaronkochEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by dobey:


Read the whole thread, and not just from the point at which you decided to hijack a thread that has been dead for months. The discussion in the thread already concluded that true dual exhaust was possible and feasible, in certain situations.

If you want to show off your build and discuss the specifics of your build, then start your own thread. And any argument you have made against any statement Will or I have made, is that "some other guy told me it will work." You haven't shown any specific data about your build either. The only thing you've said relevant or helpful to the original point of the thread so far, is your first post that brought this thread back from the dead, saying you were doing a true dual system. Everything else you've posted has just been overly defensive commentary. Stop taking every single word someone writes, so seriously, and personally. It's unhealthy. And practice some reading comprehension, so you don't go expanding a one liner that someone wrote about how your exhaust will sound/perform, into a novella.



Actually, it was me that posted the pictures of his build as an example.

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Report this Post06-22-2013 04:40 PM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by aaronkoch:
Actually, it was me that posted the pictures of his build as an example.


http://www.fiero.nl/forum/F...ML/113666-2.html#p47

Or not.
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Report this Post06-22-2013 08:11 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Arns85GT:

You really are trying to make enemies, aren't you? You haven't followed my build threads or you would know that I researched true duals for about a year before I built them. Have you built any for the Fiero? So far as I know, Asterix has taken my work and built on it better and is to be congratulated. The exhaust is designed independent of the intake, with the intention of evacuating the gases the fastest way possible, independent of the intake. The cam and cylinder are taken into account.

The calculations I used were from the book entitled SCIENTIFIC DESIGN OF EXHAUST& INTAKE SYSTEMS third edition. by Philip H Smith FI MechE MSAE, and John C. Morrison BSe PhD MI MechE It can be purchased on Amazon for about $30.

Here are the extracted calculations I used.





I did not deal with the collector, because if you do some reading on V6 racing and performance, you will soon realize that the collector recommended is pretty big. So big that you could, in theory, run the primaries without a collector and make really good power, but really noisy. Those 32" pipes act like trumpets.

The Fiero has very little room, so, with 2.5" pipe I deemed the collector requirements to be satisfied with the tail pipe system.

So, Will, show me you know what your are talking about and not just taking cheap shots.

Arn



I asked nicely twice and didn't get a response until I was a dick about it... Hmmm...

I have the book.

What volume are you calculating in the 2nd panel? (I can see it's of a cylinder...)

Which reflection does this primary length use at peak torque RPM?
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Report this Post06-22-2013 08:46 PM Click Here to See the Profile for Arns85GTClick Here to Email Arns85GTSend a Private Message to Arns85GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
Will you were not nice at all and I am not responding to your question. Read the book. I did.

Arn
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Report this Post06-23-2013 12:07 AM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post
Arn: Aaayyyymmmeeeennn, aaayyymmmeeennn, aaayyymmmeeennn, amen, amen, sing it brother!!!
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Report this Post06-23-2013 05:24 AM Click Here to See the Profile for AsterixClick Here to visit Asterix's HomePageSend a Private Message to AsterixEdit/Delete MessageReply w/QuoteDirect Link to This Post

Asterix

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Member since Feb 2006
dobey said:
 
quote
at which you decided to hijack a thread

I did read the whole thread, several times in fact. On what basis do you claim I "hijacked" the thread? Please be specific, because my build was directly related to the thread, and especially so because of Arn's comments and build.

dobey said:
 
quote
Or not.

In fact, aaronkoch was the first one to post photos of the build to this forum. I did not post my photos to this forum, only a link to my website. I conclude the significance of the difference was wasted on you.

dobey said:
 
quote
And practice some reading comprehension, so you don't go expanding a one liner that someone wrote about how your exhaust will sound/perform, into a novella.

Apparently you think comparing the sound of a Harley to what any Fiero 660 might sound like is relevant? Novella? WHAT, you didn't like my "back atcha" about three Harley V-twins and DAF trans that was specifically in response to the irrelevant comment about "Harley" sound? And, considering your condescending and out-of-context comments, and that you have NEVER responded to any "be specific" requests, who are you to point fingers about reading comprehension?

dobey said:
 
quote
If you want to show off your build and discuss the specifics of your build, then start your own thread.

So anyone who posts anything about their build must be a "show off"?! This part of my build was relevant to this thread and was specific to letting Arn know what we had fabricated. As for my "own thread" it probably never occurred to you that I had discussed with thedrue, before I "hijacked" your sacred thread, about collecting all the info/specs about my build, along with numerous photos taken over several months, to post in a thread specific to my build. So instead of asking if I/we were going to do so, you make a rude remark as though I had no right to post about my true dual exhaust build on this true dual exhaust thread.

What I have observed in your and Will's posts is that you PRESUME many things without asking first, rather saying "it won't work" or "your wrong" or "I'm the only one ..." ad nauseam. Just because Arn, or I, or thedru, or anyone else, did not post details, or comment on data, or commence a new thread that expands on a build, does not give you leave to make smarmy and condescending remarks nor to make unwarranted accusations or presumptions. Every one else that has posted on this thread has been courteous except you two. What have you brought to this thread that is of any value? In my opinion, NOTHING. ZERO. NADA.

Arn said (to Will):
 
quote
You really are trying to make enemies, aren't you?

I agree, and also that it applies as well to you, dobey.
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