Hi Guys

Was reading up on how X and H Crossover Exhaust Pipes on a Small Block Chevy not only create more power and torque, but also change the sound of the typical American V8 to that of more exotic sounding v12 by smoothing out the exhaust pulses and equalizing exhaust gases?
(some good discussions on the subject-found online)
http://forums.hybridz.org/i...osting/page__st__520
http://www.kitcentral.com/i...ile=viewtopic&t=8351

I know the engine bay of the Fiero is already tight with a v8 Archie kit mounted horizontally..... but was curious IF anyone ever accomplished bringing both header downpipes together to create an X or H type setup?

Would love to creat something along these lines for the SBC 350 using Sanderson CC2 block hugger headers that I'm putting into a Lambo replica.
Thanks
Dave M.

In my opinion in a Fiero I think it is not worth the hassle at least for HP. I have seen some done but is more a crossing than a nice flowing X. Also it will not make it sound any different than a V8. Real Lambos I have seen usually sound loud and nasty. A strong V8 I think goes perfect with it. If you want V12 then check the Fiero V12 swap from a BMW somewhere here. As a contrast here is an example of a true dual no crossing V8 sound at idle (cc10, 2.5" pipes no cats).

Short answer is no.

Longer answer is you need to tune your intake, cam, and exhaust, to fit the sound you want. The Sanderson block huggers aren't going to get you there.

Adding an X or H will equal out the two side so when it exits it sounds "balanced". There is power

gains to be had but not in a fiero, exhaust is to short and little back pressure to begin with. Ray

If you're going to do an X, then you might as well do a single exhaust.

Having the pipes split again after they join is fairly pointless.

..Not practical !! but if you are a glutton for punishment get a narrow X pipe from SUMMIT racing..cut to size
.. tho it would work for 60o V6 with truelo headers & dual exhuast,,these are 20,1/4 long with an overall width of 4 1/2 inch center to center
these X pipes are about $70 TO $80.oo

..Just use the turbo muffler of your choice,check out turbo muffler comparo test done by car craft,hot rod magzine,ect ,this will give you a better gain with less wrench pain.
mount the muffler as far back from headers as possible for best gains

AN X PIPE SET UP QUIETS THE EXHUAST IN MOST CASES

[This message has been edited by uhlanstan (edited 07-15-2011).]

Archie did it on one of his builds

Mine no X pipe


Perfect Union



The idle seems to be better but mines also running an old school carburetor
Mines louder

Research 180 Degree headers. They will give your engine a more exotic sound.

quote Originally posted by Jake_Dragon: Archie did it on one of his builds Perfect Union The idle seems to be better but mines also running an old school carburetor Mines louder

If you mean to say that car has an X-pipe, I'm ont sure that's the right description of what it actually is.



This design does create a point of divergence when the exhaust pulse travels back up through the one pipe leading to the rear bank; such that part of that pressure wave will end up travelling to both banks. That will help out a little, but doesn't quite have the same effect as a full X pipe does on a Camaro or Vette. The dfferent firing order on the LSx engines also helps make it a little easier to get a more exotic sound. That car does sound pretty nice, but I think what the OP wants is a bit more exotic sounding than that.

The stock LS7 also sounds a fair bit more exotic than the other LS motors.



It would be really cool if troyboy's car had the butterfly valve tips, too. But even with them disabled on the stock Z06, it's not especially loud.

Here is my SBC. It has both banks merged into a single 3" pipe right before the single crossflow muffler. With the exhaust merged, it has equal sound out both sides of the exhaust, but at idle still sounds similar to what you hear from Alex4mula's and JakeDragon's true dual exhaust.


While they sound very similar as posted on youtube, they would sound differently in person. In person you can hear the different pulse timing coming from the individual sides on a true dual exhaust (stereo) vs. mine would still be mono. I doubt most exhaust videos/sound clips shown have kept the sound stereo when they were recorded, so a dual exhaust setup and a merged one will sound very similar (excluding volume levels and sound pitch differences due to different mufflers).

While idle sound clips are nice, I also like to hear them ad WOT running through the RPM range:

[This message has been edited by fieroguru (edited 07-15-2011).]

180° headers will get you as close to what you want as you can get with a SBC.
Fitting 180° in a Fiero will be difficult, if not outright impossible, but if it can be done - that's what you need to do.

Here's what 180° headers sound like on a Chevy V8.

quote Originally posted by Formula88: Fitting 180° in a Fiero will be difficult, if not outright impossible, but if it can be done - that's what you need to do.

A true 180 degree header setup on the SBC has been completed at least 1 time (Eric Marsh) in a fiero. I was close to finishing my 180 header mockup for a SBC/Getrag combo, but then wanted to make sure they fit the F40, then I ditched the SBC altogether and went LS4/F40... I still have all the parts on the shelf to finish them someday.
https://www.fiero.nl/forum/A...100421-2-092757.html

The pipes are close coming out the back of a Fiero so its not as noticeable.
My Corvette has side pipes and standing on one side you can really hear the difference.

I have an exhaust setup in my shed that goes from 2 1/2 pipe to 3 inch into a muffler and then out to duel tips. I haven't heard it on a car yet but I may install it just to make my car a little more DD friendly.

For what it's worth, I don't think you need 180 degree headers to get that sound. Though they are the "easier" way to get there.

I've started thinking about the header/exhaust design for my LS4 again, and have been doing a lot of research on exhaust designs, and cam timing. Unfortunately, this is a somewhat hard process, as people who design camshafts don't like sharing the formulae they use, and people who make camshafts, don't like sharing all the details needed for those formulae. Hopefully I can find all the info I need, soon enough.

It's all extremely complex though, which is why I say the 180 degree headers are the easy way out.

quote Originally posted by fieroguru: While idle sound clips are nice, I also like to hear them ad WOT running through the RPM range:

Agree.

quote Originally posted by fieroguru: A true 180 degree header setup on the SBC has been completed at least 1 time (Eric Marsh) in a fiero.

Yup - "difficult, if not impossible."
That certainly looks difficult to me. I'd love to see it installed in person.

You should get these and let me know how they work

http://cgi.ebay.com/ebaymot...fPartsQ5fAccessories

quote Originally posted by Chris Hodson: You should get these and let me know how they work http://cgi.ebay.com/ebaymot...fPartsQ5fAccessories

Way ahead of you (and the picks were in my linked thread above). They will not clear the strut tower and have interference issue with the front/year firewall.

[This message has been edited by fieroguru (edited 07-17-2011).]

Looks like it would clear my drivers side but i think i would really have to modify the passenger side.


Thanks for posting that

No I see now what you guys are talkin about.... and it looks like the only way the 180degree headers would work would be on a longtidunal v8 mounted in Fiero like Chris Hodson.

Here's a 1973 Porsche 914 w/ SBC an 180*headers....
http://www.youtube.com/watch?v=Enr-4xpVbEQ

and the holy grail of 180*header sounds... the ford gt40
http://www.youtube.com/watc...1d_Y&feature=related

Holy Christ! what a sound!

[This message has been edited by n_tensetuning (edited 07-17-2011).]

quote Originally posted by Chris Hodson: If you could, would you measure how far each side stick out from the cylinder head?

Sorry, they got cut up and were used for the 1 5/8" portion of the mockup on the ones I was building.

Yes, now if there was only a ruler where the blue stuff is! Does anyone have 180 degree exhaust parts laying around I could buy. I would have them welded up on my car in a heart beat. Im hoping to have my car ready for the heartland fiero show in davenport this august. Im a flywheel away from dropping in the fresh block and need a plan for the exhaust. So if anyone want to help please do!

Also - sorry if I hijacked this thread I was close to starting one of my own until I saw this one.

Chris Hodson, no worries on highjacking the thread. It falls pretty much along the lines with how I would like my SBC 350 to sound.

Plus I appreciate your input as well as Fieroguru's : D

IF there was enough demand, it sure would be nice for someone to offer/make the 180*headers for transverse applications (v8 archie kits).

I believe there would be a good market for them.

Dave M.

modifying those headers is not for the faint of heart. You pretty much have to do it on the engine and the welding is pretty tricky. Especially around those 4 way collectors. But, you can tack them together, pull them out and get somebody really good to weld them up.

Arn

Thank you for the links, im going to check them out.

I can weld up a storm if I had the pipe to do so Finding the time to work with it is the hard part.

quote Originally posted by n_tensetuning: Chris Was looking thru craigslist and found some cheap 180* headers for you to consider: http://charlotte.craigslist.../pts/2464536544.html http://sanantonio.craigslis.../pts/2476913238.html http://charlotte.craigslist.../pts/2429658106.html Avg price $100 used

These second 2 links don't appear to actually be 180 degree headers, despite their ad titles. The first one is the only one that looks like 180 headers to me. But the last 2 just look like long tube headers, with some odd angles.

quote Originally posted by dobey: These second 2 links don't appear to actually be 180 degree headers, despite their ad titles. The first one is the only one that looks like 180 headers to me. But the last 2 just look like long tube headers, with some odd angles.

I agree the first one is 180 the others aren't. I bet Chris could use them with a little modding

Agreed. Only im in Iowa.