100 cfm more with anular and downleg boosters can't beat AFR

Thanks for posting that Mattax.

Ahh.....Shrinker, I wish he was still around to answer all my questions. I tell you what I did do and it helped me understand what he was always trying to get us to understand but we were to dense to grasp. I dug up every thread Bruce ever posted on I could find and categorized every topic he discussed with associated key words with in threads and grouped them together under their relevant topics. When you review all the info you begin to get an idea on what he considers important and you begin to understand why. Also as you go you pick up stuff from other extremely knowledgeable guys like Tuner and pieces of the puzzle come together.

Case in point Bruce posted this about engine tone:


This is a 417 cube Cleveland through the mufflers. The engine makes over 780hp with a 1042CFM SmartCarby on it. It is regular street driven, its not a race car. It makes 300hp at the wheels in top gear at 60kph( 37mph our speed limit). It runs at 40kph (25mph)in top gear (manual not auto) without snatching and pulls away with WOT. It passes noise laws and passes emissions. The engine was first built with a Dominator on it and it didn't have this sound, it was dull and bassy. It made similar power but had less response, used far more fuel and couldn't pass emissions.
Listen to the sound how it changes from the burnout and the RPM before the launch and compare it to the sound as it goes down track. You can hear the other car, its a dull bass sound (conventional). The sound in the burnout and pre launch is smooth and snappy, the sound during the run is sharp and supersonic. We have chassis dynoed it with pipes on pipes off etc it makes no difference it kills your ears.
During the run the sound is a sharp hard crack, Its got this crack at basically all revs when under serious load. That is the sound of supersonic flow when the valve opens. Engines that make that sound (you have to correctly identify it compared to an exhaust resonance) are usually really good efficient engines. They make high power from little fuel. Engines that sound dull and more bassy are making high levels of CO with high levels of unburnt HC and some unused O2 in the exhaust. Basically they could be better.

And then I found this from Tuner recently and the pieces come together:

Blair's chapter on mufflers and the mathematics in it (the math in the book is available in a software program from SAE) is very useful if you are at all interested in the future of motor sports in general and track public relations, the general public's opinion of hot rod cars. I know some people would rather be loud than fast, but there is no good reason to be loud, and this is particularly so when it is possible to use the sound energy to increase the power output instead of aggravate people. He explains how the mufflers can be band-pass filters and how to use acoustics to cancel the peaks of select frequencies which a particular engine emits. Sound energy lost out the tailpipe is energy that could be used in the engine for something useful. Within Blair's work is solutions to design of systems, intake and exhaust, which utilize the acoustic energy and gas dynamics to improve engine efficiency. For instance, the speed of sound, hence the reflected wave, is different in CO2, CO, H2O, etc, and in a running engine all those exist in varying quantities in (what we usually think of as merely) air flow, when in fact it is not simply air, it is a varying mixture of gasses, each with significantly different characteristics

They say we stand on the shoulders of giants and we most certainly do, but to get up to those shoulders is a long and arduous climb. I'm still climbing but I hope to someday enjoy the view from all that hard work. Anyway sorry to divert from the topic at hand.