THE RETURN OF THE TURBO
To many, turbocharged F1 engines conjure images of outrageous 1980s excess. But the new-for-2014 units are an altogether more sophisticated breed
Four years ago, just after Sebastian Vettel won his rst title, F1 announced that engine regulations were changing – not with a tweak, but with a wholesale trashing of the established order. There was talk of direct injection and bigger, better KERS. But what stood out was a blast from F1’s past. F1 was going turbo.
The deadline slipped back a year and the engine sprouted two extra cylinders, but the new power units nally arrived for 2014. New words and phrases entered paddock parlance: energy store, power electronics, MGUs H and K. Oddly, there’s been little discussion of the turbo. It has slipped out of public perception – never an allegation levelled at its 1980s predecessor.
“If they had the turbo car with the blown exhaust, nothing would have changed,” reects Lotus’s Romain Grosjean. “You don’t really feel it’s a turbo car unless, when you make your start, you hear the turbo going up in rpm. The torque delivery is nice – but there are no real changes.”
Red Bull driver Daniel Ricciardo adds: “The way the power comes in is different to 2013. Obviously the car has lost downforce, but the biggest difference is what it does on the throttle. It’s got more torque and you’re able to have wheelspin later on. With the V8s it was power from the get-go. You could have wheelspin very early in the corner, whereas it seems you can have wheelspin with the turbo halfway through fourth gear and longer through the gear ratios.
“Whether that’s the turbo engine or ERS, I have no idea. It’s a bit confusing – I just drive it!”
That last comment alone is enough to delineate the respective eras: no driver from the 1980s ever expressed doubt about what their turbo was – or was not – doing. Turbochargers dominated the landscape. They were allconsuming monsters supplying brutal amounts of barely controllable power that pushed drivers and cars to their limits. The memory of that turbo era is what red enthusiasm for the sequel.
“You got put into this missile that had 1,350bhp, and you just couldn’t change gear fast enough,” recalls Derek Warwick of his adventures with a BMW qualifying-spec M12 turbo engine in the back of his 1986 Brabham BT55. “Anything you’d learnt in practice, you
threw out the window. It wasn’t about handling, it was about power. I recall watching Riccardo Patrese, my team-mate, with clouds of black soot coming out of the back of his car because we were feeding so much fuel into the turbo.”
The modern turbo exists on a diet rather more Spartan than that of its red-meat predecessor. These powerplants don’t have the pop-off valves of yore – they’re constrained by the 100kg maximum race fuel limit and, more pertinently, the 100kg/h maximum fuel-flow rate. The target of the modern turbo is to improve efficiency rather than increase power. “We’ll never run at 5bar because, at 12,000rpm, it’s going to bring far too much air into the engine for the maximum fuel flow,” explains Renault Sport F1’s head of track operations, Rémi Taffin.
The other big difference between then and now is the issue of lag – the modern cars have the MGU-H device to sidestep the issue by spinning up the turbocharger on demand.
“The turbine wheel has been designed to be exceptionally efficient at recovering energy out of the exhaust stream, whereas previously it was just spinning up the compressor,” says Andy Cowell, managing director of Mercedes AMG High Performance Powertrains. “Today we’re driving the compressor but we’re also driving the MGU-H and the more energy there is from the turbine to drive that, the better your electrical compound load is, and therefore the better the total thermal efficiency of the power unit is and the faster your race car will be. There’s a huge amount of effort in the efficiency of that wheel and not so much effort gone into the inertia of the assembly. Large inertia turbo assemblies mean high lag, but we’ve got an electric machine and that just means speed control is not a problem with F1 turbochargers today.” This makes Warwick laugh. “When modern drivers discuss their cars, it’s amazing how much the technology has advanced – they don’t talk about throttle-lag. We used to define lag with the minute hand, not with the second hand. They were all-or-nothing, no progression whatsoever. There were tracks where you’d have to be at on the throttle as you turned into a chicane. You’d go right, then a bit left and – bang! – the power would kick in. It was horrendous. You could judge it, but with one foot on the clutch pedal and the other on the brake you couldn’t get back on the throttle until your braking was completed. It would have been dead easy with three feet…”
Over the course of eight seasons, Warwick’s turbo education took him from the Toleman-Hart I4 turbo to the Renault V6 twin turbo and, nally, the daddy of them all, the BMW M12/13 in both its factory and Megatron spec. All turbos, he says, were not the same.
“With Brian Hart, we had one great massive Garrett turbo stuck almost on the gearbox. Renault had more money: it was almost a pleasure to drive. We had good horsepower and qualifying engines – but it wasn’t until 1986, that I really experienced the power of the turbocharger, driving the four-cylinder single turbo BMW,” he says. “We had 1,350hp for qualifying, one-lap qualifying tyres and an engine that was good for maybe 24 miles. BMW would strip off the waste-gate and replace it with a blanking plate. You had masses of power. After qualifying, you’d throw the engine in the bin.”
“It was a trial and error,” recalls Jean--
With the single-turbo BMW, we had 1,350bhp for qualifying, one-lap qualifying tyres and an engine that was good for maybe 24 miles… You had masses of power. After qualifying, you’d throw the engine in the bin”
Derek Warwick, Former F1 driver
We used to define lag with the minute hand. There were tracks where you’d have to be flat on the throttle as you turned into a chicane. You’d go right, then a bit left and – bang! – the power would kick in.
Derek Warwick, Former F1 driver
Pierre Menrath, Renault Sport F1 director of testing and development, formerly a member of the Renault trackside team in the pioneering days of turbo. “For a normally aspirated engine, the lines and pipes must be neat, the ow of liquids must be optimum. With a turbo, it just has to work!
“You have to bear in mind that we went from 520-530bhp in 1979 to more than 1,000bhp in the space of ve years. At the end of 1986, we even had a test engine that was capable of developing up to 1,200bhp thanks to the use of new turbochargers, with a new design. They produced exceptional performances – unfortunately, the engine lasted only three laps.”
While modern F1 takes a regular kicking for its extravagances, it’s worth noting the above. Overspending is nothing new; indeed, part of F1’s allure has always been an obstinate insistence on technological excess. The throwaway attitude of the turbo era is a prime example. In contrast, the focus now is on extending engine life and squeezing development.
Those qualifying-spec turbos required an exclusive set of skills from the drivers. Having practised in race spec they would, in effect, go into qualifying cold, learning new braking points, coping with new gear ratios and handling characteristics on the y. It was a ferociously physical experience.
“They were tough cars to drive, very physical,” recalls Warwick. “You had the downforce and needed to make a lot of gear changes, but it was really tough because the power you had in the car was enormous. I liked that aspect of it – but I was always one of the stronger guys out there.
“I remember qualifying at Monza. It was just phenomenal. We had a seven-speed gearbox. We went up 1,500 revs on every gear ratio and we still ran out of revs at the end of the pitlane. I remember doing that qualifying lap with the most
silly grin on my face the whole time.
“The difference between the cars I drove and the cars of today is that physical aspect: the steering was more physical because you were driving one-handed and using the gearshift all the time. There was much more downforce than they have today. I’m not saying driving the modern cars isn’t difficult but it is different. Modern drivers would have coped because great drivers are great drivers in any era and they adapt – though I don’t know that a Max Verstappen-type driver would have jumped into our cars and gone quick straight away.”
While the new turbos are much more drivable than the ’80 turbos, opinion is divided as to whether they’re as drivable as the normally aspirated V8 engines used from 2006 to 2013. Unsurprisingly, given their success, Mercedes are convinced there is an improvement.
“Our job as a group of engineers is to deliver torque to the rear wheels precisely and in a timely manner,” says Cowell. “The electrical machine that recovers energy also enables us to control the speed of that assembly and thus control the boost pressure. Before the start of 2014, there were all those fears of turbo lag and ‘what’s it going to be like to drive?’ but the drivability is better than the aspirated engine because we’ve put a lot of effort into boost control, into fuel system management and therefore the creation of torque on demand.”
Taffin, in contrast, is not so convinced by the current performance of the Renault powerplant. “We haven’t yet reached the level of drivability we had before. It’s a newer engine and it’s more complex. It wasn’t easy before, but we worked for 25 years on the atmospheric engine, so were more on the case. I don’t think there is a long way to go because drivers aren’t complaining about lag. It’s more the consistency of the torque delivery and the different ways of producing that torque that we continue to work on.”
It’s a question of degree, quite different to the brutality of the 1980s equivalent. Warwick preferred the normally aspirated cars he drove once turbos were phased out. “To be honest, I wasn’t disappointed to see the back of them. After Arrows with the Megatron we had the lovely little Arrows V8. It was predictable and a pleasure to drive. All of a sudden you knew when you pressed the throttle, you had the punch.”
For the modern driver, old-school turbos are the stuff of legend, at best experienced by trying a restored classic. “I haven’t driven a turbo race car,” confesses Ricciardo. “The nearest I got is a Ferrari F40 and when I drove it, the amount of lag was the sort of thing you remember reading about as a kid: it winds up and up and then it kicks in. What we have is much more progressive – but I’d love to try an ’80s F1 turbo. Although I’d bring a few spare pairs of underwear…”
So much work has gone into boost control and fuel system management, that lag is not a problem in modern turbo-powered F1 cars
The qualifying BMW engine of Derek Warwick’s Brabham blows due to an excess of power before the 1986 Australian Grand Prix
Renault EF4B (1984)
Renault Energy F1-2104