Chris initially contacted us about getting some more power from his MK3 Ford Fiesta.

This MK3 Ford Fiesta already had a Ford 2.0L Silver Top Zetec engine conversion and a set of fast road cams with supporting modifications.

After a brief discussion, it was clear that installing a set of throttle bodies and more aggressive camshafts was the path that Chris wanted to take. With these new modifications, the stock Zetec ECU was no longer going to cut it so it was decided that a new engine management system and engine wiring loom would also be required as part of the project.

Custom Camshaft Timing Northampton Motorsport

Piper Ultimate Road Cams

Upon arrival, the first step was to put the Fiesta on the rolling road to see what the power output was. It produced 149.7BHP and 140.3LB/FT which is already an improvement from what the engine left the factory with.

From there, we pulled the Fiesta into the workshop to get cracking on the build. We started with removing the stock inlet manifold and fast road camshafts. We installed a new set of Piper Ultimate Road Cams, Piper Vernier Pulleys along with a new cambelt kit, water pump and camshaft oil seals. Once the cams were timed up, we then got cracking installing the throttle bodies.

Jenvey Throttle Bodies.

We opted to install a Jenvey Zetec TBP 45mm Throttle Body kit. Clearance between the throttle bodies and the bulk head was always a concern with this build and unsurprising it, the standard Zetec kit did not fit.

We opted to run 90mm throttle bodies (instead of 118mm), shorter Throttle Body Air Horns and a short ITG Sausage Air Filter with a stepped Carbon back plate. This gave us the clearance required without having to make modifications to the bulk head. Adjustments were also required to the original fuel lines, a new set of Bosch Fuel Injectors and Webcon Fuel Pressure Regulator.

With this part of the job now complete, we got into the engine management.

Zetec Throttle Body Kits Northampton Motorsport
Bespoke Engine Wiring Look by Northampton Motorsport

Bespoke Engine Wiring Loom.

The original engine loom was removed and a pin assignment was designed. We always document our wiring diagrams for ease for any potential future work. Once the assignment was complete, a bespoke engine harness was produced. We opted to use an ECUMaster EMU Classic Engine management system. This ECU was chosen as it’s packed with features such as Widband lambda Control, Knock Control as well as being very competitively priced. It is ideal solution for a fast road 4 cylinder engine. Once the harness was created and installed, it was fire up time! As this was not the first Silver Top Zetec engine that we have tuned, we used a previous map to design a base map to get us started. All of the engine sensors are then calibrated and she fired up with a few usual adjustments to the fuelling. We then installed the Mk3 Ford Fiesta on the rolling road to calibrate the ECU.

Rolling Road Calibration.

After mapping, the engine produced 185.3BHP and 155lb/ft at the flywheel. This is an increase of 35bhp for the previous fast road setup and 55BHP from stock. To the right, you can see the difference between the fast road setup and the Ultimate road cams and throttle bodies.

Zetec Rolling Road Comparison

Here at Northampton Motorsport, we have been carrying out conversions like this since the early 2000’s. We have experience with most car manufactures, Engine Management Systems and Throttle Bodies. If you would like more information or a tailored estimate for your vehicle, please get in touch.

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