i wonder if their is a way of making 180 degree headers for v6 fiero . i saw a corvette with this design and it sounded wicked. i know that the 3.8 has the same firing pulse as the v8s , but the 2.8 has a 120 firing pulse . i was wondering if this could be acheived with fiero engine bay being so cramped.

From what I have read "no". Something about the missing two cylinders fire in correspondence with two other cylinders. Is been a while sence I read about it but I believe it was on the 60 degree forum

Vinny

The 2.8 has equal firing pulses on each head/collector already, so there would be little benefit of doing a 180 setup on it. There was a guy in the mall trying to sell a long tube header setup for the 2.8/125C combo, but they were not 180 (nor do they need to be).

180 degree headers are normally done on engines with non-uniform firing pulses on each bank/header collector. By crossing over some of the tubes from bank to bank you can create equal firing pulses at the collectors of each header.

Now as far as space... it just take some creativity! If these will fit on the SBC in a fiero, you can make them fit on the 2.8. Once I finish the F40 swap, I can get back to finishing these:




The guy with the BMW V8 and another guy with a N* have also done 180 headers in a fiero.

[This message has been edited by fieroguru (edited 01-27-2010).]

I dont think you can run 180 degree headers on a 60 degree v6 that has even 120 degree firing impulses. Look at it this way , the even 120 degree firing impulses of the Fiero v6 will do a good job scavenging in a true dual exhaust with headers and sound like most like a Lambo

I was planning a 6 into 1 header for the solo car. Don't know when I'll ever get around to building/finishing it, though, with all the other projects.
~ Paul
aka "Tha Driver"

If you can't take the heat, get out of the nuclear reactor.

Here is the set of log tube headers from the mall:

quote Originally posted by Lilchief: I have one set of custom long tube headers for sale. I bought these in hopes of mating them with a 4T60, well not so lucky and really don't want to butcher them to make work. I got these off a PFFer that said they would work on a Fiero, but didn't know fitment with a 4T60. So I am assuming they'll work with a TH125, 4spd or 5spd. Asking price $275 plus shipping.

Like mentioned above, the purpose of 180-degree headers is to even out the exhaust pulses on an odd-fire V8 (the V8 has an exhaust pulse every 90 degrees of crankshaft rotation, so each header would need to have an exhaust pulse every 180 degrees of crankshaft rotation).

The GM 60-degree V6 is already an even-fire engine. So the exhaust pulses are already evenly spaced out (a 6-cylinder engine has a cylinder fire every 120 degrees of crankshaft rotation, and each exhaust manifold on the 60-degree V6 gets an exhaust pulse every 240 degrees of crankshaft rotation), which gives the same effect as 180-degree headers on a V8.

So to make a long story short, you neither need nor want 180-degree headers on a V6.

[This message has been edited by Blacktree (edited 01-28-2010).]

quote Originally posted by Tha Driver: I was planning a 6 into 1 header for the solo car. Don't know when I'll ever get around to building/finishing it, though, with all the other projects. .

Even in that configuration the even 120 degree firing pulses will scavenge well with the proper collector ..would like to see a pic of a collector for that config. Think of the collector as a 6 shooter and each primary fires in a clockwise or counterclockwise fashion from the previous fired primary for a swirl effect which should scavenge better

[This message has been edited by Erik (edited 01-27-2010).]

Here's an idea. A newer Tri Y 360* header. Y together 1,4 2,5 3,6 then all three into one. Don't know if it would help any in performance or efficiency and would not be easy to build. Just an idea. Oh yea I still have those long tube headers if anyone is interested, fits only with T125

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85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42

[This message has been edited by Lilchief (edited 01-27-2010).]

quote Originally posted by Erik: Even in that configuration the even 120 degree firing pulses will scavenge well with the proper collector ..would like to see a pic of a collector for that config. Think of the collector as a 6 shooter and each primary fires in a clockwise or counterclockwise fashion from the previous fired primary for a swirl effect which should scavenge better

Exactly what I had in mind. Should do well to scavenge the exhaust & get quite a bit more top end power.
~ Paul
aka "Tha Driver"

ok cool all this info is great,i just thought maybe this was the setup the guy from taiwan ( video posted on you tube )might of have used.

quote Originally posted by SinCityfiero: ok cool all this info is great,i just thought maybe this was the setup the guy from taiwan ( video posted on you tube )might of have used.

its hard to say ..its all about the firing order, revs, size of the exhaust, muffler and the intake as well working together to provide a certain sound. The taiwan car does have whatever formula for that sound for sure

[This message has been edited by Erik (edited 01-28-2010).]

I might be wrong, but I thought 180 degree headers were for V8s only.

quote Originally posted by fieroguru: Here is the set of log tube headers from the mall: [QUOTE]Originally posted by Lilchief: I have one set of custom long tube headers for sale. I bought these in hopes of mating them with a 4T60, well not so lucky and really don't want to butcher them to make work. I got these off a PFFer that said they would work on a Fiero, but didn't know fitment with a 4T60. So I am assuming they'll work with a TH125, 4spd or 5spd. Asking price $275 plus shipping.

[/QUOTE]

I'm interested in how he got these to work. I tried to fit something similar with by 4 speed Muncie and I just couldn't get the geometry right. I ended up building long tube headers for true duals to get it done. Any info? Also, was there a custom Y with the set?

Arn

Arn : Those headers will not work with a manual 4 speed. After post that thread I did some more research and found out they only work with the T125c. To my knowledge there was no Y pipe made for them. Doug Chase had these originally and tried them with a 4 speed with no luck. I wanted to use them with a 4T60 and no luck. I trial fitted these with a T125c and seemed to fit quite nicely. Minimal modification to the cable support bracket, had to bend it down a little.

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85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42

Shoten them and weld some collectors and let it rip.

ok so 180 degree headers are for v8 with 90 degree firing pluse. but what if someone applied that same principle of those headers and used them on a 60 degree v6 which cylinders would be paired up in the collectors; also would it sound any different .

A sequential firing v6 takes a completely different set of pipes to a v8 with staggard firing. What I have read from numerous sources is that your want all your primary pipes to be the same length, and that is between 22" and 36" in length

Arn

quote Originally posted by SinCityfiero: ok so 180 degree headers are for v8 with 90 degree firing pluse. but what if someone applied that same principle of those headers and used them on a 60 degree v6 which cylinders would be paired up in the collectors; also would it sound any different .

The 60 degree V6 already has equal exhaust pulses on each bank. With the firing order of 1-2-3-4-5-6 with 1,3,5 and 2,4,6 grouped on each bank - each collector will have equal firing pulses (every 240 degrees of engine rotation) with a conventional header with equal length tubes. You will not be able to pair cylinders from bank to bank to make it any better than it already is, but you could pair them up to CREATE an exhaust pulse imbalance at the collector if you wanted it to sound more lopey vs presicion smooth.

The SBC with the firing order of 1-8-4-3-6-5-7-2 and 1,3,5,7 and 2,4,6,8 grouped on each bank has a cylinder firing every 90 degrees of engine rotation. Notice how cylinders 8 & 4 and 5 & 7 are on the same bank and firing immediately after each other (90 degrees apart). This is causes each bank to have an imbalance in the exhaust pulses and is what gives the SBC its distinctive sound with a true dual exhaust.

The 180 header design for the SBC groups cylinders 1,4,6,7 and 8,3,5,2 to have equally spaced exhaust pulses on each collector (every 180 degrees of engine rotation), while they remain imbalanced on each cylinder bank.

oh see so if I where to use this method it would cause a reverse effect.so if wanted a "precision smooth" exhaust what would the best recomendation.lol precision smooth would a nice pornstar name

quote Originally posted by SinCityfiero: oh see so if I where to use this method it would cause a reverse effect.so if wanted a "precision smooth" exhaust what would the best recomendation.lol precision smooth would a nice pornstar name

You can't get any smoother than the even firing pulses of which the 60 degree v6 already has. For a V8 with a 90 degree crank you must use the 180 degree headers to get the smooth sound that flat plane 180 degree crank v8s have. Cam choice and timing can make a diff in the low RPM range for smooth sound as well.

[This message has been edited by Erik (edited 01-29-2010).]

I actually got my v6 to sound like a v8 at idle. I installed a Moroso muffler in the CAT position. The Moroso has 4 spiral baffle sets. That causes the pulses to change for the v6 and it really sounds like an sbc. I took it off because it was frankly a little too loud.

Arn

quote Originally posted by fieroguru: This is causes each bank to have an imbalance in the exhaust pulses and is what gives the SBC its distinctive sound with a true dual exhaust.

*ANY* V8 with a 90 degree crankshaft.

quote All posts <snip>

I learned something new today

FYI, here's what 180° headers can do for a 90° V8's sound.

Oh god I can't wait till I get my 3500 Fiero back. I want to achieve that nice sound at the lower rpms. It's all in the exhaust tuning. Intake tuning as well. I gotta watch some test run videos of my car now! Link in the signature

doesn't sound quite as good as i was thinking. I need to tune my exhaust. Different muffler for sure. Maybe I was thinking of another 60*v6.... Might have been an old video of the 88 Z24.

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First LX9 Fiero GT, 1987 | My Fiero Fuel Economy | MPG Display for OBD I
Youtube Videos of My GT | modernize your fiero with technology!
If you can't fix it with a hammer, you've got an electrical problem
Fiero's are people too. We pay just as much attention to them, if not more than our loved ones
screw paying those bastards. im not going to become rich by paying for things.....

[This message has been edited by americasfuture2k (edited 03-05-2010).]

When we designed ours, I looked into the tri-Y and thought for a all of one min maybe about 180s, but neither seemed worth the bother. It was a tite fit to just make ours as close to equal lenghts as we did.

The things you want to have with these V6s are good flowing collectors that feed into a big enough Y pipe with good a junction where the right header meets the lelt header. IE, 2" left, 2" right into a 2.5" down pipe. Such will give you great flow and good sound.

BTW: I like to drive my Norm Asp 87GT with our headers/Y pipe more than my turbo 86GT with our modified headers/Y pipe for the turbo because it sounds much cooler. Turbos act a lil like mufflers. I especailly love to back off the throttle.... rumble rumble pop

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[IMG]




trueleo.com
RSpiderII@aol.com

Just a thought, but how would all individual pipes sound/ perform?
ie: V6 with 6 seperate pipes and mufflers or V8 with 8 pipes and mufflers.

quote Originally posted by Francis T: BTW: I like to drive my Norm Asp 87GT with our headers/Y pipe more than my turbo 86GT with our modified headers/Y pipe for the turbo because it sounds much cooler. Turbos act a lil like mufflers. I especailly love to back off the throttle.... rumble rumble pop

I love that, it's so intoxicating.

It's also very much related to the tuning. My 2.8 with stock exhaust (even the cat is still there) does it on deceleration. The fuelling table is no longer stock though.

The key is running lean mixtures in the high vacuum parts of the fuelling table. Lean enough to cause lean misfires. Then, every once in a while, the unburned air/fuel mixtures pops in the exhaust. It's music!

Of course, the type of exhaust you have can quiet this sound, or allow it to be heard better.

quote Originally posted by ClayTonto: Just a thought, but how would all individual pipes sound/ perform? ie: V6 with 6 seperate pipes and mufflers or V8 with 8 pipes and mufflers.

They would probably sound pretty similar. As for performance, it would likely leave something to be desired.
The purpose of having collectors is so that the vacuum of an exhaust pulse helps scavenge the next pulse.

[This message has been edited by pmbrunelle (edited 03-06-2010).]

What I would like to know is IF any one has built a set of 108* that would dump into the stock fiero exhaust location?? I have a stretched chassis and am looking at different engines. I DO NOT like the sound of the V8, but MAYBE if I could get that exotic sound using the 180' s I may consider the V8. They would have to clear a 4 sp tranny and NOT go above the valve covers in any way.


What say you all??

quote Originally posted by fieroguru: The 2.8 has equal firing pulses on each head/collector already, so there would be little benefit of doing a 180 setup on it. There was a guy in the mall trying to sell a long tube header setup for the 2.8/125C combo, but they were not 180 (nor do they need to be). 180 degree headers are normally done on engines with non-uniform firing pulses on each bank/header collector. By crossing over some of the tubes from bank to bank you can create equal firing pulses at the collectors of each header. Now as far as space... it just take some creativity! If these will fit on the SBC in a fiero, you can make them fit on the 2.8. Once I finish the F40 swap, I can get back to finishing these: The guy with the BMW V8 and another guy with a N* have also done 180 headers in a fiero.

i know this is an old post but do you have any pictures of how you routed the header on the firewall side of that?.......great work by the way. be sure to take a video so we can hear how it sounds.

quote Originally posted by RUNDLC: What I would like to know is IF any one has built a set of 108* that would dump into the stock fiero exhaust location??

Eric Marsh did:
http://www.hotrodder.com/emarsh/

[This message has been edited by fieroguru (edited 11-16-2010).]

A good set of equal lenght headers -or even just headers with smooth kbends and nice collectors into a 2" Y pipe is all you really need to see/feel a big improvement over the stock headers.

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[IMG]




trueleo.com
RSpiderII@aol.com

Fiero Guru,

Could you make up a set of headers for the 2.8/3.4 PR that sounds like this? I am not so much after the performance, but this sound. I have a Mera and this would be the ideal sound coming from its pipes. There are some pics of the system posted on Pennocks but I am not sure of the routing. Some pipes do cross over to the opposite bank and then are grouped. It sounds like each exhaust pulse is being heard in sequence (1,2,3,4,5,6). Is that possible?


http://www.youtube.com/watch?v=mU23N7blxYo

quote Originally posted by Rick 88: Fiero Guru, Could you make up a set of headers for the 2.8/3.4 PR that sounds like this? I am not so much after the performance, but this sound. I have a Mera and this would be the ideal sound coming from its pipes. There are some pics of the system posted on Pennocks but I am not sure of the routing. Some pipes do cross over to the opposite bank and then are grouped. It sounds like each exhaust pulse is being heard in sequence (1,2,3,4,5,6). Is that possible? http://www.youtube.com/watch?v=mU23N7blxYo

There's a couple more threads about that exact car. Apparently someone got in contact with the builder of the exhaust on that car, and he had said he would be willing to make a similar setup for others; but at a price of course. And that car has a lot more to the system than just headers.

These might could be adapted into a V-8 Fiero although I think they would go off to the left too much and into the strut tower.

http://www.schoenfeldheaders.com/180_crossover.htm

quote Originally posted by TXGOOD: These might could be adapted into a V-8 Fiero although I think they would go off to the left too much and into the strut tower. http://www.schoenfeldheaders.com/180_crossover.htm

If you look at the thread link I posted earlier, there are pics of those headers on a fiero drive train and why they will not clear a stock fiero engine bay...