American Iron ONLY
A Cobra replica (Superformance "Super 427" ) began an upgrade from a 4-barrel carb to a custom Roush Racing fuel injection system. The 402 c.i. engine was choking on a weak fuel delivery system and should really appreciate the Roush engineered, Accel DFI Gen 7 based, update.
Strapped down and ready for a base line test
The base line dyno figures indicated there were "issues" to be addressed. The air-fuel ratio looked like a sine wave. Power and torque were way down and there was a severe lack of fuel supply beyond cruising speeds. (Click here to view dyno sheet)
A pretty face, but that's it.
The engine compartment was about receive a high tech upgrade with a flavor to match the car's period and style.
Plumbing in bad need of an upgrade.
The fuel injection system requires a complete re-plumbing of the fuel system, from tank to injectors.
Low and sleek, but where are we going to mount all the new EFI system components?
The real challenge begins in laying out all the electronics and planning a neat installation. The Cobra is a very compact platform... very lean, with none of the normal hiding places for accessories.
Laying out the harness for the ECU.
The ECU would nest between the dash and the top of the transmission hump.
Out with the old...
...In with the new.
The "Weber style" throttle body and manifold setup is a piece of jewelry, inside and out. A unique chamber was created in the manifold to tap all eight intakes for common use by the idle air control valve and the MAP sensor.
Looking good, but a big job remained.
The ECU nested nicely between the dash and transmission tunnel.
Fuses, relays and the MAP sensor mounted to the firewall.
The wiring harness required customizing to our unique component layout. All connections were soldered and industry-standard connectors were used throughout.
New fuel system mounted securely.
An Accel inline fuel pump, filter, braided feed/return lines, with -AN fittings were mounted. The gas tank needed to be dropped and a bulkhead fitting installed to accept the new return line. The throttle linkage presented a big challenge, converting from a conventional bell crank (short pull carb) to a cable system to support the Roush system's long pull. A custom pedal assembly was fabricated to accommodate the new geometry.
Ready to "roll" on the dyno.
The upgraded Cobra really came alive. Throttle response, cold start and idle were improved greatly. The real satisfaction was in seeing the results of the follow-up dyno pulls. The horsepower curve was a linear rise throughout the pull, torque was nearly "flat across" and the air-fuel ration remained constant across the board. (Click here to view dyno sheet)