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180 degree headers? by RilesOfSmiles
Started on: 07-14-2013 03:54 PM
Replies: 5 (455 views)
Last post by: dobey on 07-14-2013 06:19 PM
RilesOfSmiles
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Report this Post07-14-2013 03:54 PM Click Here to See the Profile for RilesOfSmilesClick Here to Email RilesOfSmilesSend a Private Message to RilesOfSmilesEdit/Delete MessageReply w/QuoteDirect Link to This Post
Anyone know where to get some for a 2.8? I'm looking for that exotic sound that would go so perfectly with the Fiero. Assuming of course it would even sound good.
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Report this Post07-14-2013 04:02 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
180 degree headers are for V8's where they have unequal firing pulses on each bank (when looking at each bank separately). They allow you to intermix the primaries between the banks to end up with 2 collectors with equally timed pulses that are 90 degrees out of phase with each other.

The 60 degree V6 already has equal firing pulses on each bank, so all you need to do is make equal length headers. Once done, there would be 120 degree phase shift between the pulses at the collectors, but perfect uniformity in the timing of all exhaust pulses.

[This message has been edited by fieroguru (edited 07-14-2013).]

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RilesOfSmiles
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Report this Post07-14-2013 04:05 PM Click Here to See the Profile for RilesOfSmilesClick Here to Email RilesOfSmilesSend a Private Message to RilesOfSmilesEdit/Delete MessageReply w/QuoteDirect Link to This Post
Equal length headers? WANT.
Is it possible to buy them? I have the exhaust system crafting skills of an infant.
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IMSA GT
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Report this Post07-14-2013 04:05 PM Click Here to See the Profile for IMSA GTClick Here to Email IMSA GTSend a Private Message to IMSA GTEdit/Delete MessageReply w/QuoteDirect Link to This Post

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Blacktree
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Report this Post07-14-2013 05:18 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
Repeat after me: 180-degree headers are only for odd-fire V8's. Their purpose is to even out the oddly-spaced firing pulses in a V8 engine (so each header gets an exhaust pulse every 180 degrees of crankshaft rotation). First of all, the 60-degree V6 is an even firing engine. So no funky header setup is needed. And secondly, on a V6 engine, each exhaust manifold gets an exhaust pulse every 240 degrees of crankshaft rotation (not 180 degrees, 240 degrees).

Sorry to gripe, but every time someone asks about 180-degree headers for a V6, someone posts the funky exhaust on that Fiero in Taiwan and says "here ya go!" No, those are not 180-degree headers. It's a funky multiple-Y setup.

That said, the Trueleo guys used to make "almost equal length" headers for the 2.8 V6. I did before/after dyno tests with their headers, and they show a noticeable improvement, even compared to ported manifolds with an aftermarket Y-pipe. Unfortunately, they had to stop production, due to medical issues. But hopefully, they'll be back in business soon.
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dobey
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Report this Post07-14-2013 06:19 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 RilesOfSmiles:
Equal length headers? WANT.
Is it possible to buy them? I have the exhaust system crafting skills of an infant.


Find shop that makes custom headers, and do it well. Pay them lots of money. Done.

Or just buy the "sprint" manifolds and y-pipe from The Fiero Store. Combine it with the Pacesetter cat-back system they have, or a Spintech muffler with a cat-back system from West Coast Fieros, and call it a day.
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