Don't bum out because this post was originally concerned with
FOMOCO products, it's got some decent non-brand-specific information
regarding crossover equalization in dual-exhaust applications.
No, I don't know whether Dr. Gas sells stuff for Chrysler products.
Forwarded without permission...
Ron
> There was an article in the June or July version of Mustangs Monthly
> that talks about these in the context of a late model 5.0L install.
>
> To quote from the article:
>
> "[The sound of a Dr. Gas crossover being heard in Winston Cup races
> this year] is reminiscent of the Ford GT-40 and the vintage Formula
> 1 V-8 Cosworth - a unique sound developed with a 180-degree exhaust
> system.
>
> "Why was the 180-degree exhaust system necessary anyway? The reason
> engine tuners used 180-degree exhaust systems was to eliminate firing
> order pressure differences between the right and left cylinder banks.
> [A] V8 four-cycle engine, during a power cycle, [will have] two
> cylinders on the same bank fire within the same 90 degrees of
> crankshaft rotation."
>
> The author goes on to explain that this creates an imbalance between
> the two banks, and, under certain circumstances, it creates a "reversion
> effect" wherein an exhaust pressure wave is reflected back into the
> manifold and collides with the exhaust gases coming from the next
> exhaust stroke. A balance tube will help in low and mid-RPM conditions
> to reduce this effect, but it will not work at high RPMs. Other designs
> which work at high RPMs fail to resynchronize the pulse and pressure
> spikes in an engine system. Supposedly, the "synchronizing crossover"
> that is employed in the Dr. Gas system "evenly splits, smoothes [sic],
> and synchronizes exhaust pressure waves at all engine speeds...
> Additionally, secondary scavenging will continue to take place."
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:07:32 EDT