"I don’t now why it’s 560 times. But that’s what we had to pass," he smiles.
"You can pass it by tightening the rebound damping so the wheel doesn’t move, but that obviously compromises the handling. Let me tell you what happened to one of our competitors when we put it through the pothole test, all the suspension and steering bent, including the subframe."
Johnson became involved in the Focus RS project at an early stage, but after the basic project definition.
As a result, he was handed a two-wheel drive design with a budget to match.
In the six months set aside to produce a watertight, production plan, however, it became clear that four-wheel drive was essential to match the power output necessary for the required performance. His next challenge was to fight for a budget to make that happen.
"Raj Nair [Ford’s head of engineering] takes the credit for that," says Johnson.
"Even up to the final meeting we weren’t sure we’d get the go-ahead. Our finance man was presenting the numbers, but we were getting questions from everywhere. And I was thinking we’d all be packing up our desks and moving onto something else."
"Then Raj said do it, but don’t ask me for another dollar of budget."
Those words set Johnson’s next three years in motion. So despite being a limited volume car of around 20,000 production models a year, the Focus RS is designed to all Ford’s mainstream engineering targets – hence the pothole test.
The electronic engine calibration – a major part of the programme – was completed for all global markets and handed over to mainstream Ford engineering teams. A huge undertaking in itself.
A vital ride and drive won over that team when Johnson persuaded them to incorporate pops and bangs in the exhaust – normal procedures would calibrate the exhaust noise to be as calming as possible.
Johnson strived for the best for the Focus RS and it worked. His team created a hugely memorable fast Ford and enthusiasts will benefit from that.
That's worth remembering when you next see or hear a Focus RS and it brings a smile to your face.