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Campbell X-PIPE™

PO Box 8857

Alta Loma, CA 91701

PHONE: (nine zero nine) 821-2199


Campbell X-PIPE™ Acoustic Super Charger® Exhaust

                                 What is it?

Please take a moment to understand why the Acoustic Super Charger® powered Campbell X-PIPE ™ exhaust is such a powerful and profitable invention. The Campbell X-PIPE™ exhaust is the most cost effective and simplest way to make real horsepower on any engine.

Background. To better understand the Campbell X-PIPE™ exhaust, first look at the extremely successful 4into1. The 1940 era 4into1 was "tuned" (timed) by joining multiple equal length head pipes into a single, larger diameter collector to communicate and maintain momentarily, a periodically produced scavenge (suction) pulse generated by the high velocity exhaust gasses alternately exiting each head pipe. The collector allows this scavenge to 1. reduce atmospheric pressure in the non-exiting pipes, and 2. exist slightly longer within the exiting pipe to help extract residual exhaust gasses from that cylinder. When introduced, the 4into1 was a remarkable improvement over the log manifold used on the poor flowing flat head engines of the day.

However, 4into1 limitations became apparent over the years as engines, but not 4into1s, evolved;

1. 4into1 tuning is static and limited. Modern engines lose low rpm torque. The fixed head pipe length creates a minimum rpm torque range because atmospheric air has time to push hot exhaust gasses back into the head pipe between exhaust pulses, filling the cylinder and even the intake manifold, reducing power.

2. The power band drops off at high rpm. Exhaust pulses are slowed down and stack up as they enter the larger collector cross sectional area, creating excessive back pressure. (As a result of these constraints (1 & 2), a highly tuned 4into1 will usually have a very narrow power band.)

3. As engine cylinder head design improves air flow, scavenge becomes over-scavenge (as unburned air/fuel from the intake manifold can more easily loop through intake and exhaust valves during overlap, to be sucked out the tail pipe as unburned air/fuel; HC emissions).

4. Air/fuel mixture varies radically depending upon rpm; at low and high rpm, the mixture has full strength, but at the tuned rpm over-scavenge removes unburned air/fuel, weakening the mixture and reducing dynamic cylinder pressure.

5. *High compression pistons are used to improve reduced dynamic cylinder pressures at tuned rpms.

6. *High octane fuel is used to prevent detonation during un-tuned periods of normal dynamic cylinder pressure.

7. Special cam shafts are used to improve the high rpm power. Long duration exhaust cams open the exhaust valves earlier, cutting into the power stroke, to dump additional combustion energy into the head pipes (robbing combustion energy from the power stroke) to increase exhaust gas pressure to overcome top end back pressure. Because the power stroke event duration is decreased, the engine loses thermodynamic efficiency.

Enter the Campbell X-PIPE™ exhaust! It changed everything. 1. Tuning is not based upon head pipe length and can be dynamic. 2. The power band is much broader because scavenge is not lost at low rpm and back pressure is not produced at high rpm. 3. A high performance engine will not be over-scavenged because the Campbell X-PIPE™® Acoustic Super Charger® exhaust does not need to create and maintain suction to work. 4. Without over-scavenge, engine mixture does not vary between too rich and too lean and back to too rich as rpm increases. 5. High compression pistons are not needed because dynamic cylinder pressure is not lost. 6. High octane fuel is not needed because high compression pistons are not needed. 7. Special 4into1 cam shafts are not needed because additional exhaust duration is unneeded and wasteful.

(* Although not needed, these items can be added to the Campbell X-PIPE™ exhaust for improved performance.)

So, where does the HP come from, with the Campbell X-PIPE™ exhaust? The engine is more thermodynamically efficient (it generates a greater dynamic cylinder pressure while using a longer, more efficient power stroke), it is more fuel efficient (due to reduced over-scavenge) and it works with fewer engine modifications. As a bonus, since the Campbell X-PIPE™ exhaust can work with a short duration exhaust cam (allowing a longer power stroke) exhaust gas temperatures (EGTs) are cooler. Cooler EGTs can allow the tuner to lean the mixture to make even more power, on less fuel!

The Campbell X-PIPE™ exhaust is not a something for nothing device. Rather, it gives you what you thought your 4into1 promised: More Power, Everywhere! In addition, the Campbell X-PIPE™ exhaust gives you a broader power band and greater fuel economy.

Now, you know why!

Campbell X-PIPE Acoustic Super Charger® Exhaust

How does it work?

Finally, the Acoustic Super Charger® exhaust!

Scavenge is followed with modern wave charging.

The future of high efficiency exhaust designs!

Wave charging (using high energy exhaust gases to compress intake air) was first designed and patented for diesel engines around 1916. Many designs and patents have followed over the years as sealing problems, incompatibility with any form of exhaust back pressure (muffler or catalytic converter), and major design changes became necessary to allow its use on gasoline engines (low throttle bypass valving, intercooling, and critical mixture compensation controls) resulted in a less than desirable horsepower adder for the street. Intake charge boosts of up to 40psi were limited to narrow power bands, narrow operating temperature ranges, and off road applications.

Enter the Acoustic Super Charger® exhaust

The Acoustic Super Charger® exhaust uses a two step process to improve performance: 1) scavenge is used to remove burnt gases, & 2) wave charging is used to compress free radicals and fresh air into combustion chambers. Where centrifugal, roots and screw compressors rob crankshaft power, or turbo chargers create back pressure, the Acoustic Super Charger® exhaust reduces back pressure and improves cylinder pressure without loading the crankshaft. Where roots and screw compressors boost low end, or centrifugal and turbo chargers boost only top end, the Acoustic Super Charger® exhaust introduces multiple power bands to boost low, mid range and top end. Where all super and turbo chargers are expensive, heavy and increase engine temperatures, the Acoustic Super Charger® exhaust is inexpensive, adds no weight, and actually reduces engine temperatures.

Low end: Big Block power: Wave charging following scavenge allows hot exhaust gases to push unburned air/fuel back into the engine, filling the combustion chamber with a high energy mixture.

Mid range: BIG Block power: Wave charging following scavenge produces a noticeable benefit at highway and normal operating rpms. Torque increases of up to 40% are common.

Power band enhancement: Power gains of 8% over conventional scavenge systems is common. Scavenge systems are converted to wave charging. Though tuned by means of equal length head pipes, to a particular rpm range, usually about 8,000 rpm, wave charging prevents overscavenge during resonant mode. Precious air/fuel is recycled, increasing dynamic cylinder pressure and decreasing exhaust emissions of unburned air/fuel (HC). No mixture change is necessary for normal operation. The Acoustic Super Charger® effect is so great that optimum power usually results when the mixture is leaned out and the timing advanced 2 – 4 degrees!

Top end: Unending top end: If your engine can take the rpm, the Acoustic Super Charger® exhaust can give you the power you want. Back pressure is reduced: Crossectional area does not have to increase, so there is little slowing of the exhaust pulse. Pulse velocity stays high. The exhaust pulses can get out of the system in time for the next scavenge and wave compression cycle.

Long Duration Cams: Are no longer needed. No need to increase exhaust duration and rob power stroke duration and efficiency. Your engine runs cooler, pulls stronger, lasts longer. No combustion energy is wasted pushing exhaust out of a scavenge exhaust. Normally wasted combustion energy is converted to crankshaft horsepower.

Catalytic Converters: Restrict exhaust flow, increasing back pressure, and reduce scavenge. But, the Acoustic Super Charger® exhaust reduces traditional scavenge induced back pressure and air/fuel overscavenge, thereby compensating for converter back pressure and preventing heat damage to converters. Converters and the Acoustic Super Charger® exhaust can co-exist in a high performance, high efficiency, and emissions legal environment. No need to strip off converters and install MIL eliminators. No reason to risk vehicle seizure for smog violations. Acoustic Super Charger® exhaust is the hassle-free performance answer.

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