SEMA 2015: Performance Distributors’ Adjustable D.U.I. Distributor


The Cross-fire cap allows each spark plug wire to exit on the proper side of the engine.

Steve Davis and the folks at Performance Distributors have been at the ignition game for decades; it’s just ‘what they do.’ Their Davis Unified Ignition (D.U.I.) combines a high-energy coil with a precision-curved distributor that works exceptionally well. But there is always room for product improvement, and that’s exactly what they have on display this year at the SEMA Show.

“We’ve upgraded our deluxe Chevy street-strip distributor with an adjustable slip-collar for situations where blocks have been decked, or heads have been milled, so you’re not bottoming the distributor out on the oil pump,” says company representative Brian Caruth.

They’ve also added a polymer gear to the distributor assembly. No more worrying about whether you have the right gear, and wondering what kind of gear goes with what kind of camshaft — the polymer composite solves those worries.

(Left) Polymer gear design is compatible with all camshafts. (Right) The adjustable slip-collar.

One thing to note is that the polymer does not wear like a bronze gear, but it does wear slightly; over time it will be smart insurance to replace it every so often — depending upon usage — to ensure the camshaft timing doesn’t vary.

It’s also important to note that every D.U.I. distributor is custom-curved for the application. The company will ask for your cam specifications, compression ratio, and other pertinent details so they can create the ideal curve for your modification level.

“The D.U.I. uses a 50,000-volt coil which is rated for 7,000 rpm, and includes a high-dwell module to increase spark duration. This allows us to open spark plug gaps to .055-inch and improve the flame kernel,” says Caruth.

The company’s Crossfire cap is designed to simplify wire routing, as the left-side wires exit on the left, and the right-side wires on the right. No more crossing wires — or ignition signals.

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Jason Reiss

Jason draws on over 15 years of experience in the automotive publishing industry, and collaborates with many of the industry's movers and shakers to create compelling technical articles and high-quality race coverage.
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