Side Pipe SPL

[Machiavelli]

Iconic AC Cobra chassis, my little pipe dream can be done (800 BHP pushing 1025Kg)
http://partywave.deviantart.com/art/...ssis-135866249

[Richard Hudgins]

Gentlemen,

The chassis was designed for a 302 block. That block is 1 inch shorter than the 351 block. There was plenty of room for the primaries with that configuration. (And plenty of power as well)

The turn that has to be made (351 based) to clear the chassis is not as restrictive as one might think. But I am not about to get into a discussion about flows and sonic reflective pulses in multi-radii bent pipes.

Particularly since we are dealing with supersonic flow and heated boundary layer effects that make even seasoned acoustic engineers run and hide.

Suffice to say this. A couple of 351 block based engines have been dynoed with the standard JBL headers and with headers from Stahl, Hedman, and JBA. The percentage difference in power between the makes of header has been surprisingly low. 1>2% has been the normal spread. (The JBL design was not the best performer but it was in the middle of the grouping.)

Also one minor thing.

Comparing the JBL chassis to the Iconic is insulting to the vehicles creators.

You guys figure out which designer is peeved by the comparison.

[Machiavelli]

Hi Richard,
I imagine the Iconic engineers are quite peeved, their $500K roadster is being compared to the very affordable JBL which has a better chassis, and looks that drive the women wild!

[Rare Iron]

Originally Posted by Machiavelli

Eric (Rare Iron),
Your chambered flow-thru exhaust makes sense, specifically when dealing with the sound reflection aspect of your "stamped" outer muffler shell to block the leakage from the inner 3" (or 2.5") diameter inner tube. I have also looked at everything on your website, all pictures show a head-on view of this "stamped" muffler concept. Just curious, because sound radiates 360within any chamber, and the annoying higher frequencies like to bounce on metallic surfaces, do you also stamp the opposite sides of your "powersticks" (not visible in the photos)? If not, why not? From where I sit, as long as you maintain that inner 3" (or 2.5") diameter clean flow-thru path, you have double the capacity to block those unwanted higher frequencies by stamping both sides? (Maybe they need to be staggered in some way, but you get the idea)

Machiavelli, the Powerstick muffler is a chambered muffler - Cobrapacks are smooth & not chambered (you probably already know this). The crimps in the outer shell of the chambered mufflers create a soundwave anomaly which "tune" the exhaust - they give the exhaust a very unique sound. I'm not sure what you are asking about my crimp design. I crimp them at 12:00 & 6:00 positions, with relief areas at 9:00 & 3:00. Other chambered designs crimp at all 4 positions. My design pattern gives mine a different sound, as well as my perforation pattern in my cores. All combine to make them what they are.

[vector1]

no comparison here, and i would have preferred a 302 based engine.

[Machiavelli]

Thanks Eric, the crimps at 12:00 & 6:00 positions answered the question.