Fiesta 1.6 EcoBoost Makes 500bhp

The only Mk8 Fiesta in the world running a four-cylinder 1.6 EcoBoost. 503bhp, built in-house at Pumaspeed.

Ford decided the Mk8 Fiesta would never have a four-cylinder petrol engine. We disagreed, bought a salvage car, and put a 1.6 EcoBoost in it. It now makes 503bhp on 2 bar of boost and holds a Dragy record for 100–200km/h in under seven seconds.

Figures recorded on the Pumaspeed dyno. 440bhp on medium boost is the setting the car runs as a daily driver.

Ford said no four-cylinder. We said watch this.

When Ford announced the 2018 Mk8 Fiesta range would be three-cylinder only — 1.0T and 1.5T, no petrol four anywhere in the line-up — a lot of our customers took it badly, and with good reason. Plenty of them had already spent serious money on the 1.6 EcoBoost: forged bottom ends, hybrid turbochargers, 330–350bhp track cars. That investment suddenly had nowhere to go.

So we bought a brand-new 140bhp 1.0 EcoBoost Mk8 in December 2017 to find out what the new chassis was actually like. It was a revelation. Sharper, better balanced and far better finished inside than any Mk7 or Mk7.5 we had run, and a simple set of Eibach Redline springs transformed it. The platform was superb. The engine was the only thing holding it back.

The obvious answer was to give the best Fiesta chassis Ford has ever built the engine it deserved.

Phase one: 340bhp, an X-47R, and six days to spare

In April 2018 we sourced a second Mk8, a damaged 1.0 from a salvage auction — broken strut, front hub and driveshaft, bent rear axle, panel damage and new bumpers needed at both ends. It was stripped and repaired first so it would run and drive, then the real work began.

The hard part was never the mechanical install. It was the electronics. The Mk8 runs an entirely different CAN bus to the Mk7, so we needed a standalone ECU that could talk to it and keep the standard dash, connectivity and sync all working. Specialist Controls rewrote their SCS Delta ECU to the new Mk8 CAN protocols — and did it in a little over a month so we could make our Ford Fair debut.

The engine itself came from our own Fast Ford-featured 335bhp "Red Rocket" Fiesta track car, dropped in with custom driveshafts and bespoke engine mounts. Designing and building that hardware took about two weeks. Rewiring the four-cylinder harness into the Mk8 loom took considerably longer, and was finished to a genuinely factory standard by Racing Circuits in Leeds.

It fired up six days before the deadline. Three days before its launch it was finished, then driven 140 miles to Silverstone for Ford Fair, taken straight out on track, pushed to the X-47R's 340bhp limit, seen spitting flames more than once, and driven 140 miles home again.

The X-47 family of ST180 hybrid turbochargers — the generation that took this car to 340bhp in its first form. Still the backbone of our 1.6 EcoBoost range today.

Phase two: 503bhp and a reverse-rotation G25-550

340bhp was the start, not the finish. The car you see here now runs a very different engine: our own ductile-linered block, 2-thou undersized Omega pistons, balanced Sainz lightweight rods good for a 8,750–9,000rpm redline, a ported Area 6 head, Stage 2 cams on uprated Piper single valve springs, and a 35%-overflow Bosch direct injection set modified with double seals to keep the OE tip position.

On top of that sits the piece of engineering that makes the whole thing work: our Garrett G25-550 tubular manifold kit with a unique reverse-rotation exhaust housing and a Tial 44mm external wastegate screaming straight to the floor.

The Pumaspeed Garrett G25-550 reverse rotation external wastegate kit. The reversed housing allows far shorter primary runners from the head, which is why a turbo this size still spools like a small one.

Engine management is an SCS Delta GDI standalone built specifically for Mk8 CAN data, calibrated by EFI Parts in Runcorn, and fully integrated into the stock loom. The result is 440bhp on medium boost for daily use, or 503bhp at 29 psi on 22 degrees of ignition when you want all of it.

The full specification

What Fast Ford made of it

Fast Ford ran the car as a feature in November 2019, and put it in the context it belongs in: the long line of fast Fiestas that runs from the XR2 and RS Turbo through the ST150 to the Mk7 ST180. Their verdict was that tearing a brand-new award-winning car apart on the basis that you reckon you can do better is a bold move — and that the result is a trailblazer rather than a curiosity. The first Mk8 road car to run a four-cylinder EcoBoost, and on the evidence, not the last.

Credit: feature in Fast Ford Magazine, November 2019.

Why this matters if you own a 1.6 EcoBoost

This car exists to prove a point: the money you have already put into a 1.6 EcoBoost is not stranded. The engine moves. We have been doing this since 1998 — a 1.7 Puma engine into a Fiesta that year, a 466bhp 4x4 Cosworth conversion in 2001, a Focus RS Mk1 engine into a Mk6 Fiesta — and we can supply new or used engines plus effectively all the hardware needed to drop a fully prepped 300bhp-plus EcoBoost into whatever you are building.

You do not have to go to 503bhp to benefit from what we learned here. The same turbo families, the same fuelling and the same mapping work sit under our off-the-shelf kits.

The parts behind the numbers

Pumaspeed Garrett G25-550 Reverse Rotation External Wastegate Turbo Kit The exact turbo system on this car. Reverse-rotation housing, short primary runners, Tial external wastegate. For serious builds chasing 500bhp. £4,800.00 inc VAT  RRP £4,995.00

Pumaspeed Direct Bolt on G25-550 Turbo Kit – 440+bhp The same G25-550 turbo in a direct bolt-on package for the Mk7 ST180. 440bhp proven on our own dyno, no fabrication needed. £1,499.95 inc VAT  RRP £1,599.00

X48R Fiesta ST180 1.6 EcoBoost Hybrid Turbocharger Bolt-in hybrid for the 1.6 EcoBoost. Big power on the stock manifold, and the sensible step up from a standard turbo. £999.90 inc VAT  RRP £1,059.90

X49RS Fiesta ST180 1.6 EcoBoost Hybrid Turbocharger – 350bhp Our 350bhp hybrid for the ST180, and the current best seller in the range. Proven power graph, bolt-in fitment. £759.90 inc VAT  RRP £875.40

X47 Classic Fiesta ST180 1.6 EcoBoost Hybrid Turbocharger The classic X-47, the turbo family that first took this very car to 340bhp. Still the entry point into proper 1.6 EcoBoost power. £799.90 inc VAT  RRP £809.90

Build yours

Whether you want a bolt-in hybrid, a full G25-550 kit, or a complete EcoBoost engine swap into something that never had one, we have done it before and we hold the parts.

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