Oerlikon Graziano Round Table
Supercars, Electric Vehicles and Innovative Transmission Solutions
On the eve of the Geneva motor show and the launch of the Lamborghini Aventador, Tony Lewin spoke to leading executives from Oerlikon Graziano, the Italian-based specialist transmission supplier and provider of the Aventador’s innovative transmission. Graziano also provides the dual clutch transmission for the McLaren MP4-12C and a new seven-speed AMT for the latest version of Aston Martin’s V8 Vantage. Among the executives around the table were:
- Marcello Lamberto, current CEO
- Paolo Ramadori, managing director, becoming CEO
- Paolo Mantelli, head of automotive transmissions
- Claudio Torrelli, head of product development
- Mike Everitt, managing director of Vocis driveline controls, an associated company of Graziano
McLaren has chosen dual clutch
transmission for its recent MP4-12C supercar, yet Lamborghini has a different
solution and Aston Martin has a single-clutch AMT. Do these represent different
brand philosophies? Which is the optimum solution?
Mike Everitt: I’m not sure there is one right answer. Brand is certainly one thing: what the manufacturer wants the car to feel like is absolutely one of the driving factors behind the technology that he chooses. The Lamborghini essence is very much focused around emotion and being involved around the car in a very visceral way – and the ISR shift technology in that [the Aventador] absolutely delivers that. It’s a fast and quite aggressive shift, and that goes to the heart of what Lamborghini is. This shift can of course also be comfortable, but of course it cannot ever be as comfortable as a DCT.
Is it a question of Lamborghini trying to be different to everybody else?
Mike Everitt: They set many aspirations for the car, not least of which was a substantial reduction in the package space available for the transmission. This new gearbox is considerably smaller than the one it replaces (the Murciélago). One of the main reasons that drove this was interior packaging: they wanted to put the seats much closer together to achieve a smaller frontal area. This actually improves the feeling of space inside the car, even though it’s in fact smaller. The gearbox had to compromise in this and take less space, so that would have made the adoption of a DCT extraordinarily difficult anyway because they are naturally somewhat bigger.
Paolo Mantelli: The layout of this car is very different, as the gearbox is at the front of the (mid-mounted) engine and projects forward between the seats. So Lamborghini turned this packaging constraint into a new challenge and said they would go with an AMT – but it must be the fastest-shifting AMT in the world. For their most exotic car they wanted a step up [over the Gallardo] so they wanted to do something unique, and in a very short time frame. Packaging-wise and shift-time wise, they set us a challenge.
What exactly do the [supercar] customers demand? Is it the fastest shift, and does this vary from brand to brand?
Mike Everitt: It’s definitely different between brands. In terms of what the customer wants and what he needs, they aren’t necessarily the same thing. You don’t need a Ferrari or a Lamborghini, but you do want one. The fact that it can [do a particular thing] does rate fairly high in many people’s buying decisions, even though they may not use that particular feature very often – top speed is the classic example. Knowing you can is psychologically quite important to buyers, and on the occasion that you want to experience that absolute top end of the capability it is hugely impressive to do and the experience is memorable.
Is the Lamborghini ISR actually faster than a DCT?
Paolo Mantelli : It depends on how you define shift time.
Mike Everitt: Yes, it is certainly faster than any other AMT using synchronizers that has ever been on the market. The only way to make it faster would be to change to a dog-clutch system as used in motorsport, but then refinement would be a problem.
So is your solution on the Aston Martin V8 on the milder end of the spectrum?
Paolo Mantelli: Yes, it is more of a grand tourer interpretation of the AMT and it is a further evolution of what they have used so far. Already, the calibration and setting of the Aston system was perceived as a very good one, more comfort-oriented but nevertheless remaining a grand tourer application. In this case, the base transmission evolved into a seven speed, and the S-cam supplied to Magneti Marelli directly to Aston Martin is a further evolution of their own S-Cam type system. The radical innovation is the weight of the transmission. The car is 30 kg lighter, and most of this savings is in the drivetrain, especially the transmission. The transmission is bespoke for the torque level of that application. Originally we went for a single transmission platform for them, which we developed to go on both the V8 and V12 versions. In this case, it is designed to be fit for purpose in a lighter car and with the V8’s torque range application. For the first time, we moved out of our normal territory of forced lubrication and into splash-type lubrication – so there’s a further increase in efficiency there. It’s a very focused transmission, to fit the image of the car.
Would you like to supply Ferrari?
Paolo Mantelli: We do supply them with the V12 application on the 612 and the 599 GTB Fiorano. The FF [with a Getrag DCT] will replace the 612 soon, but we are still on the 599 today. The FF is a different application of the California’s transmission.
Is Graziano considering moving into fully automatic transmissions?
Paolo Mantelli: Not torque converter-based automatic transmissions – we are not in that field. That’s ZF territory, and we’re not stepping into it. Our main focus and engineering activity is in the sports car applications, where the torque is very high and the performance is really crucial. So, we are at the top end and coming downwards, not like the other companies where they start from comfort applications.
Mercedes-Benz has a planetary automatic with a wet clutch instead of the torque converter, giving quite a sporty feel. Does that type of application hold any interest for you?
Mike Everitt: Effectively, it’s a conventional automatic with one half of a wet double clutch. [Independently of Graziano] we at Vocis have worked with AMG on the control and hardware side of this prior to its launch in 2007. It’s an interesting transmission technology. At the moment there is no sign of anyone else picking it up, though they [Mercedes] are rolling it out onto an ever-increasing range of vehicles.
Marcello Lamberto: I would also note that that area is now occupied by ZF as an independent supplier, even for niche applications like Aston Martin, which regularly uses automatic gearboxes. They rely on much higher volumes; we are much more focused on niche applications. Our gearboxes are bespoke and customized to each individual platform. We believe that with the range we have now developed, from the extremely high-performing AMT for Lamborghini, to the DCT which is doing so well for McLaren, and a very efficient AMT for Aston Martin, we offer a complete range of solutions for our customers – excluding the fully-automatic, which is offered by ZF.
At the opposite end of the scale, you are investing in transmissions for electric vehicles. Will we see a progression from single speed to multi-speed, and will you be able to offer gearchanging without a clutch?
Mike Everitt: There are ways of changing gear without a clutch. There are things you can do with an electric engine – one of these is to make the engine react very quickly compared with a combustion engine. But you cannot defeat physics: if you are going to move a motor from, say, 8,000 rpm down to 5,000, you’re going to need either time or power. You can’t instantaneously bring it out of one gear, slow it down 3,000 rpm and engage the next gear without either waiting or experiencing some kind of inertia or shock. So you either accept a clutchless shift, which feels not perfectly smooth, or you introduce a clutch to make it as smooth or as sensation-filled as you like. We are developing a seamless-shift, two-speed transmission which is running on rigs and on a vehicle right now, and which will be released to the press quite soon.
Is the two-speed box necessary in order to get a useful top speed?
Mike Everitt: Our first application with this technology is in a small-to-medium commercial vehicle. It is particularly useful there because the payload, the difference between laden and unladen weights, is very high on a delivery vehicle like this. If you’re stuck with a single speed, when the vehicle is heavily-laden you can only climb certain gradients and accelerate at a certain rate; all of this compromises the vehicle. But if you pick a low enough ratio so these aren’t a compromise, you limit the top speed. So, having two gears is a very useful attribute. You can easily afford to carry a few kilograms more in the gearbox to get considerably more utilization on the vehicle – either making it go further on the same amount of battery energy, or having a smaller battery but the same range.
Are two speeds as far as it needs to go, or are you looking at more?
Mike Everitt: We’re working on a transmission right now that has “several more than two” ratios – we can’t be specific about it yet. This is for quite a high-performance electric vehicle, and it gives us a high top speed. In principle, it’s no different to a combustion engine. Electric engines are inherently efficient across a broad speed range, but they’re not perfect. If you want a large range of performance, if you have more ratios you have more flexibility on what you can do – just like your legs on a bicycle.
Marcello Lamberto: The concept of shifting speeds without torque interruption can be carried across different torque and power ranges, from city car applications to commercial vehicles, to normal cars and sports cars. We are in touch with several customers about potential applications.
Do you see electric vehicles as a big area of future business?
Marcello Lamberto: Potentially, yes. The crucial thing for us is to get together with the customers. Everyone is looking to get a foot in that door, but no one can say for sure what the volume will be. They want to have cars available and to test the market – that’s what we want to do with them. If we are in the first or second generation with them, then we might evolve with them. From the design standpoint we are focusing on the niche applications, the top performance applications, and volume-wise we want to be in the low-to-medium area, where the customer is not interested in doing it in-house in a captive manner.
You came up with an innovative packaging solution for your DCT on the McLaren. Do electric vehicles present opportunities for even more radical gearbox architectures?
Claudio Torrelli: The two-speed that we have developed does have what could be termed a standard layout, so it is just one primary shaft, a secondary shaft and the differential shaft. But it is in the intimate detail of the gearbox shifting systems that we achieve the seamless shift through the use of a standard clutch and a sprag clutch. This same concept can be applied to more ratios, where needed.
Mike Everitt: The multi-speed transmission we have alluded to is particularly innovative. It can change gear with different degrees of seamlessness and has absolutely no clutches whatsoever. It’s really a very clever design and we are in the process of looking at the patents; the layout is truly innovative. Theoretically, you can shift from any gear to any other gear. It’s one of those things that is so clever than when you see it you think it’s so obvious and ask why no one has thought of it before. The company we are developing it for like it very much. They will be in a position to announce their part of the program in the early summer.
Is the new multi-speed as versatile as a DCT when it comes to controlling the character of the transmission through the electronics?
Mike Everitt: Yes, in every respect apart from launch. With launch you’ve got more to play with with a combustion engine as you can modulate the engine itself, the clutch and the traction control – you can make the car launch very efficiently or very spectacularly. But with an electric machine, if you don’t have a clutch your launch is pretty much dictated by what the motor can do; once you are launched, beyond that you are as flexible as with any other transmission.
Story Filed: 6/07/2011
By Tony Lewin, managing editor DCTfacts.com