exhaust note

[vega]

Somewhere in a dark corner of the "internet" lies a video of somebody that somehow crossed the leads from the header pipes so instead of all the primaries going into one collector some go into the other side collector........that produced a very exotic sound.

 

Can someone tell me a little more about his process?

 

180 degree headers are NOT going to fit in my car so I am starting to try and find other options that will make a higher pitched more exotic sound (not rice...). Also if someone were to custom make them for the car, we are talking in the greater thousands.

 

Working with a 327 chev. I love the sound of muscle, the car is not muscle and should not sound that way, or to the best of my ability to quench it.

 

Looking to make it sound like a 348 Ferrari. It has the most balance of deep and high pitch that I have found of all the cars. It uses a 90 degree v8 just like a sbc.

 

http://en.wikipedia.org/wiki/Ferrari_Dino_engine#V8

 

Exhaust clip

Are there any other options I may consider? Lets please stay on topic and factual please.

 

Much appreciated.

Edited April 12, 2012 by vega

[vega]

Empty post

Edited April 12, 2012 by vega

[Josh280z]

no clip

[vega]

I have tried posting it twice and it wont post... youtube search 438 exhaust.

[vega]

Finally got the link to work after 3 tries guys.

[vega]

I just found this on the ferrari forums.

 

"An american V8 with a cross-plane crank doesn't fire alternate banks consistently. The firing order means that you sometimes get successive exhaust pulses into the same manifold. In a dual exhaust, this means inconsistent pressure pulses in the two sides.

 

Look up "beat frequency". When you have two frequencies that are almost -- but not quite -- the same, the difference causes a low frequency pulsation (beat frequency) that gives the american muscle car its distinctive low frequency rumble.

 

The same thing happens in twin engine aircraft when you don't "synchronize" your props -- the rpm difference between the two props makes for a low frequency throb you can feel as an intermittant vibration.

 

With pure alternate bank firing, the Ferrari engines have identical pressure pulse rates into both exhaust manifolds, so the exhausts are "synchronized". After that, it's just a matter of tuning the exhaust paths.

 

So, no, a Ferrari type exhaust on a cross-crank engine will not replicate the Ferrari exhaust note.

 

Some newer GM V8 engines have cross-connections between the exhaust sides to reduce the exhaust "rumble"."

 

I also found that the 348 had a flat plane crank, I thought that it was a cross plane, so my bad there.

 

I would like to know more about the cross-connections that are done on newer cars if you guys know anything about that?

[zero]

There's already a pretty lengthy thread on this.

 

[Edit] Saw you posted in it so you clearly have read it, haha.

Edited April 12, 2012 by zero

[vega]

Yes I am friends with braap on fb as well.

 

I learned today that the smaller primary give more tq and higher pitched sound. The larger the less tq and the deeper the sound. Also H pipe for deeper, x pipe for higher. Lastly chambered style exhaust gives a higher pitched sound as well. The original flowmaster 40 apparently is higher pitched.

 

I haven't found anything else yet.

[vega]

 

v8 m3 - these have a cross plane crankshaft. Love this sound. I was under a 545i today (same engine) they use shorty headers and a x pipe. I don't know what the deal is with the muffler though. I don't know if the ITBs that they run would affect it that much really, because I have heard vettes sound like this.

 

m3 Header

http://www.porscheboost.com//images/imported/2012/01/404364_10150626271018169_103189758168_11-1.jpg

 

Does anyone have any info on this?

[vega]

http://www.corvettegarage.com/product/corsa-touring-exhaust-system-for-c5-and-z06-corvette.html

 

Check the sound bites out

[vega]

"To replicate the Ferrari exhaust note exactly will take 1) Single plane crank with shorty equal length headers and a short overall length exhaust system, (shorter length is higher pitch). 2) 180 degree headers of equal length, as short as possible with the primaries to retain as much high pitch as possible along with as short of overall length. This will get you 90% there. 3) 8 into 1 headers all primaries being equal length, again as short as possible. 4) Some mufflers such as Spintech have a unique of absorbing the tones that give the domestic V8 that old boat drumble giving a more distinct crisp smoother "raaaaaaaap" to the exhaust note with a hint of off beat rumble. Listen to youtube sound clips of c-5 &C6 Vettes with spintechs for an example.

 

Not positive about diameter and it's effect on exhaust note/tone. Pretty sure smaller equates to higher pitch due to higher velocities, if that is indeed the case, finding that balance of small but so small it is restricting.

 

Spintech is a chambered design, I dont recall if they offer a Stainless version, if so Stainless will last much longer than mild steel, 15+ yrs. Not sure how long the mild steel versions would last, 5 years?

 

So shorty equal length headers that as soon as possible go into one collector, an x pipe, and then to a chambered designed muffler. Do muffler lengths and tips change the pitch? Im not sure, I would suspect it would, but only slightly. Most likely would the tone coming from the shell of the muffler/exhaust as it rings from the sound traveling within, most likely noticeable only standing right next to the muffler if..."