JCB’s Hydromax tests in UK ahead of hydrogen land speed record attempt

JCB’s Hydromax has been testing in the UK ahead of its runs on the Bonneville salt flats in August, when it aims to set a new land speed record for hydrogen-powered vehicles.

Just over a month after the project was unveiled, the car has now been built and is currently in the middle of the second week of testing at RAF Wittering in Cambridgeshire.

RACER was in attendance on Tuesday to see the car running with land speed record holder Andy Green OBE at the wheel, where it achieved a speed of 177 mph on a mile-and-a-half stretch of tarmac at the facility.

“We are working up towards 200 miles an hour, which is fast as we comfortably can go here with the acceleration braking distance, and gradually winding the wick up on the engines,” Green said. “We're starting from last week with a car that had never run before – actually having not had both engines running in the car before – through to the end of this week, where we've got a car that reliably and consistently can start accelerate up to the limiting speed for this one and a half mile strip, and then slow down again safely to stop using brakes, steering parachutes, etc, and we most of the way through that.”

During its run, the car was pushed to 45 mph by a V8-powered Land Rover OCTA, at that point the clutches automatically engaged and Green pulled away on his own. Slowing down, an initial light press on the car's fiction brakes – there mostly as a redundancy in case the two parachutes fail – is followed by pulling the parachutes and bringing the car to a halt.

The 32-foot long car is powered by a pair of hydrogen-powered JCB digger engines, fettled to deliver 800 horsepower each, with both mated to a six-speed Xtrac gearbox. Tuesday’s run close to the testing limit of 200 mph came despite the car being fueled with gas to 350 bar pressure – around half what it will be for its record attempts – both engines churning out just 350 horsepower each, and the car only getting into third gear as the team continues to work through an extensive testing checklist. The team, led by motorsport powerhouse Prodrive on the ground, also had to contend with a minor coolant depressurization issue.

“It's been a successful day,” said Ryan Ballard, engineering director at JCB and the Hydromax project’s leader. “Somewhat frustrating initially, obviously, a few little hiccups to get ready on the car, which held us back from testing. However, we've just done our 14th run here at Wittering, we've achieved a speed of 177 miles an hour.

“We did hit third gear yesterday [Monday], but as we hit third gear, we saw a power drop, so it's the first proper pull through third gear.“We're short shifting at the moment. We'll extend that over the next few runs to increase that shift point all over to about 4300 rpm.

“So a brilliant run, everything went to plan despite those hiccups. We’re going to make some more calibration changes, change some of the sampling frequency on some of the sensors to jack that up a bit, change the shift point on the engines, and then get back out.”

Green added, “We're also just refining the change lights, the beep, and all the other indications with the intention I can hit that exactly every single time. 

“So to 3900 rpm in first gear, which is a little over 100 miles an hour, probably 110-115 then change up to second gear, get up to 3900 rpm, change up to third gear,” he said. “When thinking about two big engines, the JCB clutches and the two gearboxes all need to be synchronized to within a few milliseconds to make all that happen, and that's now happening seamlessly. So, another huge result for today.”

The car is aiming to crack the 350 mph achieved by JCB’s last land speed record car, the Dieselmax, which still holds the diesel land speed record 20 years on. Green was the driver on that project too, and feels the team is in much better shape than it was at the same stage last time.

“It's spookily similar in terms of all the DNA that you can see the layouts: twin engines, three JCB clutches, twin Xtrac gearboxes, but although the DNA is incredibly similar, every single part of the car has been re-engineered,” he said. “The only bits that they bought exactly the same part over the catalog are the tire pressure valves. Every other piece of it has been – no, that's not true, same driver – every other piece of it has been changed, which is extraordinary, and yet it feels remarkably similar because of the layout. 

“When we look at the Dieselmax, it was very basic, and it was very limited in what we can do. Now, the technology, the software, the ability to make the car work, it has half the number of switches, and it seems to be able to do an awful lot more.

“It's not the ‘this is impossible’ feeling that we had 20 years ago when we were actually testing the car, because at that stage we still hadn't actually managed to get engines running at 750 horsepower on the dyno,” he said. “We weren't even sure it was possible. They were literally the last engines did the final break in and pass off, put in a box, and it was on the overnight up to the airport to fly up to the States to get it from the car. It was that tight. 

“By comparison, having a couple of weeks to spare feels luxurious, but let's not take that for granted. There's still a lot of work to do, boys and girls over there who are working on the car right now, they’ve had about three hours sleep overnight, because it was a lot to do yesterday and a lot to do today. They know just how much work there is to do. The fact that they are so good at what they do means that we have not just got a fighting chance, we've got a really good chance of doing it.”

Testing of Hydromax will conclude later this week before the car is shipped over to Utah. There, it will take part in Speedweek, with the car running two 600 horsepower engines then, before they’re swapped out for the 800 horsepower units for the FIA land speed record attempt the following week.