Quote:
Originally Posted by swamp2
Despite all of the words above/below my criticism stands. You want to have your cake and eat it too in your sound "analysis".
Sure everyone knows about the "warble". When do we hear that. IMO, mostly at idle only.
It really doesn't matter which bank is firing what matters is that one bank gives two consecutive firings that go into one set of headers and typically into one half of an exhaust system. Thus the warble could be eradicated with clever/non-standard exhaust piping.
Terminology? All common inline engines 4, 6, 8 have an even distribution of firing, they fire every X degrees, period. The same is true for the V6, V8, V12.
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If you can't hear the distinct difference between a cross plane vs flat plane V8 through the rev range there is really no point debating this. And not sure what you mean by that I want to have my cake and eat it? I have just pointed out how the firing sequence of the cross plane V8 creates some issues that neither the I4, I6 or flat plane V8 has. Which creates exactly the sound we are discussing here. The I6 don't have that issue, the I4 neither, nor the flat plane V8. Which is why your analogy about the I6 vs flat plane/cross plane V8 sound makes no sense.
If we do an experiment with sound and use a person beating on a drum as an example:
If he keeps the following beat:
Bam - Bam - Bam - Bam
or
Bam - Bam - Bam - Bam - Bam
or
Bam - Bam - Bam - Bam - Bam - Bam - Bam - Bam
or
Bam - BamBam - Bam - Bam - BamBam - Bam
(if you say the last one out load you will notice that you actuall recreate the "warble" at idle from a cross plane V8
)
Then the first three are more similar as they "only" vary in beat per minute (or number of explosions per revolution). The last one also has the same number of beats (or explosions) per minute as number 3, but 4 of those are out of rhytm with the rest of the explosions (not out of rythm relative to crank rotation, but out of rythm per cylinder bank). That not only happens at idle, but all through the rev range and is audible (not saying that it sounds bad, just that it has to sound different). At idle, due to the low frequency the off beats are more discernable as the "warble". As revs increase the "beats" are closer together so it creates a different character, but it still sounds different from a Ferrari V8.
As you pretty much said yourselves above, whith "clever piping" the warble and distinctive cross plane sound can be eradicated. Which is EXACTLY what I have said numerous times in our discussions. You NEED to have a cross bank exhaust like on the F1X M5/6 and on the original GT40 to get rid of the warble. The "problem" is that you need to cross the exhaust banks before the exhaust tubing meets the collector for each bank. Easy on the S63 with it's inboard exhausts and on the GT40 with it's rear engine layout where you can have the exhaust above the transmission before exiting. Not so easy on a front engine RWD car with a traditional outboard exhaust side on the engine.
And in what you call "terminology" you have answered your own question. For engines like the I4, I6, V12 and flat plane V8, the firing order is not just even per crank degree, they are also even per cylinder bank. The cross plane V8 isn't firing evenly per cylinder bank and unless you direct the uneven exhaust pulse from one bank to the other bank (so that it replaces the uneven exhaust pulse on that bank with an even exhaust pulse, one that is in sequence with crank rotation) BEFORE the collector, then you WILL have a different exhaust sound from what a flat plane crank V8 has.
But now that you also acknowlegde that it takes "clever" (Ford did it in the late '60ies and BMW does it on the S63Tu in the M cars) routing of the exhaust to eradicate the cross plane V8 sound, we actually agree