Tech secrets behind the LaFerrari revealed
29th Apr 2013 8:01 pm
Roberto Fedeli, technical director, Ferrari, reveals tech secrets behind the power and glory of the LaFerrari.
When did work on the LaFerrari actually begin?
We started the project around three years ago. We had a concept before in the development process. But actual work started only three years ago.
What was the objective of the car? Was it meant to be just an Enzo replacement or did you have any specific targets like a particular car, top speed, acceleration or handling?
First and foremost we focused on delivering a car that our customers would enjoy driving. Of course, one has to keep in mind certain targets in terms of technical specifications. But most importantly, our focus was on making a car that would provide a driving experience never felt before in any other car.
The LaFerrari uses a carbonfibre chassis, which you’ve been using for some time, but with this car, you’ve taken it to a whole different level. Could you elaborate?
We added 140kg to the car with the hybrid system. Which means we had to save the same amount of weight to keep it at the same level as the Enzo. In order to do that, the biggest challenge was slimming down the tub (or the frame). And so for this, we used the best technology available to us, the same as is used on our Formula 1 cars. Both the Enzo and this car use carbon fibre, but on this car the grade used is very different. There are three grades in general - T700, T800 and T1000. We’d used T700 on the Enzo while on the LaFerrari, we’ve used the other two. Now while they weigh the same, when using the T800 and T1000, the amount of material required is much less, because it is much stronger.
Was there any objective with the stiffness of the chassis?
The target was the same as on the Enzo but we managed to make it 27 percent stiffer due to its superior design. Today, the stiffness is determined more by crash tests than by handling objectives.
You have a unique arrangement with the fixed seats and moving pedals. Is this a function of reducing weight or is there some other objective?
No, it's not only to reduce weight. It is important from the point of view of safety and weight distribution as well. If you fix the position of the seat, the position of the driver is fixed relative to the windscreen. This means that the trajectory during the crash is defined in a very static way and it does not change. You also have the weight of the driver in exactly the same place, which is good for weight distribution.
Coming to the aerodynamics and the underbody of the car; we were told a lot of technology here comes from Formula 1 too.
We have greater freedom here than in F1 obviously; there are no rules here. But we’re also using the knowhow and methodologies that F1 uses. We have some moveable surfaces on the body, in the front and the rear. There are two parts on the diffuser and three parts on the front underbody of the car that are active. The spoiler is fully moveable as well. The key was to find the optimum compromise between drag and vertical load in every condition you drive the car. The most important parameter, however, is lateral acceleration. The more of it you have, the more downforce you need. This means that you have to add to the basic downforce by moving some surfaces. This is completely automated and activated based on the speed of the car and if you’re about to take a corner.
The suspension on this car however is quite different from a race car’s push rod system.
Yes, we’re using the same geometry as the 458 and the F12 (the arms and components are different but the geometry is the same).
Coming to power delivery, you send all the power to the rear wheels.
Yes, the electric motor generates 160bhp and the 12-cylinder engine generates 800bhp. All of it goes to the rear wheels because of weight distribution. The weight ratio is skewed 59 percent to the rear. We have used the e-diff as usual.
We hear that traction control is a bit special on this car?
On this car, we have another (faster acting) source of power we can control; the electric motors. So, on the traction control, we use the electric engine to control the amount of torque generated. Normally one would need to cut back on the torque generated by cutting fuel or throttle on the engine. But there is a delay when you do that on an internal combustion engine. In comparison the electric motor is much faster and comes into play by instantly cutting back on the torque.
How does your HY-KERS system work? If you hold the throttle for around 20 seconds don’t you lose power?
If you’re on a track with long straights that would of course suck all the energy from the battery. But on normal road-traffic conditions, the HY-KERS system works perfectly, rarely ever running out.
Did you never think of a four-wheel-drive on the LaFerrari?
No, weight becomes an issue with four-wheel drive systems, so we stuck to two-wheel-drive.
And what is the kerb weight of the car?
We are at the same level as the old Enzo, 1255kg. We’re pushing to reduce that as well. The battery weighs 66kg but I’m sure we can do better.
The V12 engine is from the same 65 degree family as the F12?
The family is the same, the block is the same, but the materials used are different as we want to obtain the maximum power at high revs as we have the electric motor at low revs. We have maximum power at 9250rpm. The redline is at the same limit. We designed the engine to produce maximum power at maximum revs. This means, at low revs, we lose something when compared to the F12. But we have the electric motor here to supplement.
Is this gearbox similar to the F12 as well?
The first part of the gearbox is the same, but we have to connect the electric motor, so, back part of the gearbox is completely different. When we conceptualised the car, we had initially planned to give it an electric-only driving mode. You can drive out of your garage or drive out using the electric motor, although we haven’t gone for a full-fledged electric mode.