Unique Fiero 2.8 iron exh...

[SappySE107]

Has to be like waste spark, since they fire both cylinders near TDC. 1,4 6,3 2,5 Those are the pairs.

[bob442]

ok, i got 3 different firing orders from all of everyones posts and pictures, and i translated all of the chinese, it basically said some dude owns a small shop, built this car, had it sit for ever, moved, and is now trying to sell it. and the video, he revs the motor and it sounds like the engine load changed, like a bike changed gears....
1-4, 2-5, 3-6
6-1, 2-5, 3-4
6-1, 5-4, 2-3

[87SC/SS]

Looks right to me based on what I've read on this thread so far. Here is an animation of a 60* V6 I found.

http://www.youtube.com/watch?v=s47o3IhKXfU

That would certainly require some creative fabrication on an Fbody.

[bob442]

has this gone anywhere with anyone? i got some next to new long tube headers for materials all cut up, and i'm waiting on flanges. i just found this while looking for a link to forcefirebirds photobucket for header pictures to build off of, but instead i found this ;P
i'm gonna draw something up based off of that lovely paint shop picture, minus the turbo haha

EDIT: is this correct?

[Driver_10]

see, the 1-6 firing order of the 660s makes me wonder why this would even be necessary? exhausts left bank then exhausts right bank alternately the same way the 180* headers dump out exhaust....

am i missing something?

I thought about that, and I think your right.

I mean, a 660 is only going to fire 1 cylinder from either bank per exhaust stroke, right. That means that a set of even-length headers with common length y-pipe and 2-1 merdge should, in theory, produce the same effect assuming that that the two "sister-pulses" approach the 2-1 merdge at the same time.

As long as the pulses from the opposing cylinder banks reach the point of resonation simultaniously, then it shouldnt matter whether or not the separate primaries are seperately linked since the pusles are naturaly taking a similar path.

I would also assume then that the use of a "helmholz" style resonator (like a classic glass-pack) would further eliminate those nasty, stagnating frequencies (AKA r-r-r-rasp!) and give a nice melow exhaust tone at all points in the rpm band.

(I hope that Im not missing something)

[Jonpro03]

I want to do it. Does each of the paired cylinders have to have the same length before it's collector?

[Driver_10]

i got a SIMILAR(yet less pronounced) effect with dropping the factory muffler and throwing on a long glasspack, but it would be something i'd lust after, knowing it's going to be out of my budget for quite some time.

Actually, I have always wondered why 660's produce a somewhat similar sound when turbo'd? I think that a turbo
+ resonator would rid you of any rasp, although I dont think that it would sound nearly as good as a 180 degree header system. + turbo.

[robertisaar]

i got a SIMILAR(yet less pronounced) effect with dropping the factory muffler and throwing on a long glasspack, but it would be something i'd lust after, knowing it's going to be out of my budget for quite some time.

[Driver_10]

Whoops... I guess I got my cylinder pairing wrong. I kinda drew a similar picture on a sheet of paper while reading.

That would sound sexy as hell.

[Driver_10]

Lol. Blades come in for the new band saw tomorrow, trust me the itch is killing me.

Well, these headers I am talking is a 6-3-1 system, like the first video. What the intended purpose is to pair two cyls at TDC to help evacuate the opposing cylinder, thus creating the sound of three flat planes on a crank.

Hey john, correct me if Im wrong, but that would mean pairing 6-1, 2-5, and 3-4, (I hope that I got that right) Wouldnt that require 3 separate 2-1 collectors?

[robertisaar]

LOL, that is exhaust hell.

[Jonpro03]

[Superdave]

so i was thinking about it a bit more....

combine 1-4, 2-5 and 3-6 cylinders together for this 180* effect? then to a 3-1 collector? damn these are gonna be complicated...

Yep, that's the idea.

[robertisaar]

so i was thinking about it a bit more....

combine 1-4, 2-5 and 3-6 cylinders together for this 180* effect? then to a 3-1 collector? damn these are gonna be complicated...

[robertisaar]

LOL, with a V8, i guess there's actually 6 Y's but i see the point.

i see 6-1 headers for straight 6 motors.... and they look fairly straightfoward.

i'm interested in results here.

i have a hard time seeing all of this fitting nicely in a FWD application though... but i imagine it is possible with enough tweaking and prototyping.