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Rod has really worked hard to improve the system, and to answer some of the criticisms about warm air intake at take-off power etc. Here is a series of emails he sent me as the system evolved. Click on any picture for a blow-up.

John, I now have a 3" alum tube extension in lieu of the turbo hose. It is flared to fit the front of the ram air valve. A hole is cut in the top of the aluminum tube just ahead of the ram air valve and a fiberglass duct is incorporated to cover it and supply cool air the filter. This solves the cool air source for the filter. Now I have a system that has a separate cool filtered air, separate ram air and separate heated air in the event that a bird strike occurs. Still using the spring loaded air door as a safety device in the event of total inlet blockage.

I will keep you posted on the progress and let you know the dimensions for the system using the RU-2510 and RU-2520 filters. John, forgot to mention that the canister I sent you has been modified . I have increased the diameter by 1/4" to provide more side clearance for the 540 cu.in. motors. I have also made arrangements to have a machined alt air door kit that is to be put in with #8 screws rather than being riveted in. This will make the kit easier to put together and service the spring in event of failure.
Rod

John, a few pics on the latest version.. This system will allow fresh filtered air when the valve is closed and not rely on the warm inside air from the lower cowl. This system prevents any loss of fresh ram air pressure and still uses the cool outside air available in a full time filtered air system that most aircraft use. In the event of ice or bird strike and the total inlet closure then the spring loaded alternate air door opens and allows the warm inside air to enter. I have a spring loaded billet door with integrated hinges for the alt air and it screws into the canister with #6 screws for ease of maintenance. Post on your web if you want as I am still working on my own site.

The latest mod provides ram air pressure, even when the valve is closed (i.e. through the filter). When the valve is open, the air bypasses the filter.

POOR MAN’S SUPERCHARGER

Give your favorite toy that extra inch. @ Altitude

PERFORMANCE

Actual results are verified on my own RV8 resulting in 1 in. increase in MP @ 200mph.

The GPS airspeed on a Harmon Rocket with this system went from 220kts to 227kts.

A ½ gph fuel flow savings was observed saving approximately $2.00/hr

DESIGN

This system is designed primarily for fuel injection motors using the forward facing sump. John Huft was nice enough to share an idea with me using a ram air valve attached to the front of a K&N filter. I discovered that it was too efficient and resulted in a reverse air flow into the bottom cowl when the ram air valve was activated and the filter pressurized. This problem was resolved using a canister around the filter to contain the extra boost pressure. The canister also includes a spring activated door that opens into the warm inner cowl air. Further testing provided good results but the “warm” filtered air caused a slight MP loss requiring an outside air source for cooler air. Taking the design a step further resulted in an aluminum extension with a bypass hole that supplied outside air to the filter when the ram air valve was closed. Now outside air is used for both the ram air and the filtered air. This is now a complete “self contained ram air/filtered air” system ready to bolt on.

This system is installed on a RV8A using a stock cowl and a vertical fuel injector with an optional 90deg elbow. This replaces Van’s filter box and is a direct hook up with no modification to the lower cowl.

The cost for the forward mounting kit is $650 and $75 for the optional 90deg. adaptor

Rod Bower Aviation

N180RB@aol.com

559-972-6291