Unique Fiero 2.8 iron exh...

[robertisaar]

rather than 180* of crank rotation, they're more accurately thought of as 180* out of phase.

[ForcedFirebird]

I have a feeling that GravyManager is wanting 240* headers, not 180*. Definitely more involved to make than just 180* equal length.

"180*" headers just means you are pairing TDC cylinders. Works on v6 and v12...

http://www.burnsstainless.com/V-12ExhaustDesign.aspx

I felt I should make an update to my previous post in this thread.

As some of you know I took out a headgasket a few weeks ago. While I had the heads off, I decided to put my other bottom end together, opening up the ring gaps slightly (for boost), and upgrading the fasteners to ARP (Main studs, rod bolts and head studs).

While it was apart I noticed a small pinhole in one header where the primaries mated to the collector, I wrapped the headers and Y-pipe with exhaust wrap, and retarded the base timing by about 10 degrees or so (I still need to pull out my timing light and set it properly).

What I have noticed this time around is that the exhaust note is much more mellow, much closer to the sound I would like to hear from my car. I will have to get some video soon. But still need to buy a good action camera to do so, a phone camera is just not good enough.

[caffeine]

I have a feeling that GravyManager is wanting 240* headers, not 180*. Definitely more involved to make than just 180* equal length.

Not sure how much room you have to work with under the car but a good way to reduce the raspiness is to attenuate the frequency with a 1/4 wave resonator, depending on what range you want to silence.

That is something along with a couple other ideas I have that I want to look at.

[robertisaar]

[34blazer]

In relation to earlier discussion in this thread about equal length left and right headers, into equal length Y-pipe into turbo, that's exactly what I have in my 240Z.

[ATTACH=CONFIG]8524[/ATTACH]
[ATTACH=CONFIG]8525[/ATTACH]
[ATTACH=CONFIG]8526[/ATTACH]
[ATTACH=CONFIG]8527[/ATTACH]
[ATTACH=CONFIG]8528[/ATTACH]

I gotta say it sounds like a pissed off 2 stroke when it gets up on full song.

I don't have any videos yet, other than an idle video in the winter when I had some injectors that didn't work out as well as I would have liked.

I'm actually looking for a way to get the raspiness out of it. I have some ideas, just not sure what I'm going to try first.

Not sure how much room you have to work with under the car but a good way to reduce the raspiness is to attenuate the frequency with a 1/4 wave resonator, depending on what range you want to silence.

In relation to earlier discussion in this thread about equal length left and right headers, into equal length Y-pipe into turbo, that's exactly what I have in my 240Z.







I gotta say it sounds like a pissed off 2 stroke when it gets up on full song.

I don't have any videos yet, other than an idle video in the winter when I had some injectors that didn't work out as well as I would have liked.

I'm actually looking for a way to get the raspiness out of it. I have some ideas, just not sure what I'm going to try first.

[bob442]

Not sure what you want to see, add me on Facebook and I'll send you what you want to know, not active on here anymore. Getting out of the hotrod scene and more into trucks.
Robert warcimaga on Facebook

[GravyManager]

Back from the dead! I joined this site specifically to do research for a future engine swap in my Miata. The 660 v6 has basically all of the attributes I'm looking for. I never knew they could sound this good. I've got PLENTY of room in front of the engine to do something similar once I actually do the swap. Bob, could you possibly re-host your pics? Only a few of them are showing up. Anybody else have their own variation of these things? Or is it just the guy in Taiwan, and Bob?

Thanks in advance.

[bob442]

what are you trying to do John :P

[ForcedFirebird]

What did the pairing end up as? 1-6, 2-5, 3-4?

[02GT_Skyhigh]

Incredible job so far,

Subscribed for the long haul.... keep it up

[Jonpro03]

Bad ass

[Driver_10]

I have just found my new favorite thread.
Man, I cant wait to hear this thing. Vids are an absolute must.