What’s new? Ferrari V8!

ferrari_v8

A screaming turbocharged engine forms the heart of Ferrari’s second new car in less than a year, but don’t for one second think that the 488’s V8 is some sort of re-hashed California T motor

Like waiting ages for a bus and then two come along at the same time, Ferrari has signed off its second turbocharged engine in just under one year. Following hot on the heels of the California T eight-cylinder, the 488 GTB V8 is another fine piece of IC art from Maranello, proudly sporting a pair of twin-scroll blowers.

It’s been quite a wait for Ferrari fans that have a particular fondness for all things turbo; prior to Cali, one has to go way back to 1987 to find a charged road-going creation from the Prancing Horse – the acclaimed F40 with its 2.9-liter F120A power base.

But the long wait, it seems, has been worth it as those buses are now coming along regularly. As revealed in the June 2014 edition of Engine Technology International, the Cali’s 3.85 design is a powertrain tour de force, blending breathtaking performance with efficiency. But if that sounded impressive, the 488 moves things considerably further.

Forty years on from unveiling its first midrear- engined V8 berlinetta, the 308 GTB, the 488 has been developed with engineering input gleaned from Ferrari’s F1 and GT activates, as well as the XX program. And on paper alone, the 3,902cc turbo seems explosive to say the least: 670ps is delivered at 8,000rpm, meaning a specific power output of 172ps per liter – a new record for a road-going Ferrari conception.

Impressive, right? But wait, there’s more: there’s 760Nm torque at 3,000rpm in seventh gear and a throttle response time of just 0.8 seconds at 2,000rpm in third gear, which Ferrari claims is a new benchmark. Unsurprisingly, the 488 has some blink-and-you’ll-miss-it acceleration times: 0-100km/h in 3 seconds flat and 0-200km/h in just 8.3 seconds.

Performance, efficiency and response times were three important strands that underpinned the 488 V8’s development program, says Michael Leiters, but Ferrari’s technical director also admits those same three targets presented some of the greatest technical hurdles too, especially with the added use of a turbo.

“This car is an icon for the brand, so we needed to get things right. With this engine, we had to beat the best and improve the 458, which is a very good car. We had challenges, especially with the new engine and the use of turbo technology.

“We worked hard to improve the base engine, as well as targeting the flat crankshaft and dry sump with new oil pump that reduces friction by 30% of the overall friction of the oil pump. We also have roller fingers to further reduce friction, but these are basic areas that we always try to improve. The biggest challenge, undoubtedly, was the turbo and meeting our goals.” The issue, Leiters says, was a straightforward one – on paper at least: “We needed to increase the performance of the engine despite downsizing to 3.9 liters, and achieve good responses of the powertrain. That’s not easy to do with a turbo, especially with the response times we wanted.”

So, that meant the 488’s engine, on which development work began around 30 months ago, benefits from a raft of sophisticated engineering measures. High-tumble intake ports that are specially shaped to perfect the flow coefficient and swirl motion in the combustion chamber for a homogenous charge even at high revs, combined with 200 bar direct fuel injection, are employed. There’s also an ion-sensing system that measures ionizing currents to control ignition timing and adaptively predict misfires, as well as a multispark function that enables the spark advance to be maximized at all revs. That new oil pump that Leiters mentioned earlier, supplies oil at either high or low pressure levels, in-turn serving to reduce hydraulic power requirements by up to 30% compared with a conventional pump. Meanwhile, cylinder heads with roller finger followers drive down the power absorbed by the valvetrain by 10% at low revs thanks to less friction arising between the valve stems, tappets, camshafts and finger follower roller. Further friction reduction comes from the turbos that are placed on ball bearing mounted shafts, while the compressor wheels are made from a low-density titanium-aluminum alloy, which, thanks to its low inertia, ensures maximum spool-up speed.

Like the California T engine, the 488’s turbos are not only also from IHI, they’re a twin-scroll type too, but there are key design differences stresses Leiters, who replaced former technical engineering director Roberto Fedeli around a year ago. “If you look only at the turbos, the 488 turbos are much bigger. Yes, it’s still a twin-scroll but it’s a totally different design, especially to help with those response and performance targets for this car, as well as getting a different sound.”

In fact, the 488 gets its very own engine code – F154CB – unlike the Cali’s F154BB internal digits. “The California T and 488 is one family of engines but this is a high-performance engine, even more high-performance than California T, so that means we have some differences.” Said key differences between the two turbo power bases include a new intake arrangement, which is specific to the 488 to ensure combustion efficiency; that new oil pump; and an extensively redesigned dry sump. For the 488 V8, which Leiters says was benchmarked against “all competitor sports car turbocharged engines”, the twin-scroll technology directs the exhaust gases from each cylinder through separate scrolls and increases efficiency of the exhaust pulses for maximum power. A special seal on the turbine housing ensures a minimum gap between it and the compressor wheel for maximum efficiency. These solutions result in those class-leading response times with zero turbo lag.

Staying true to Ferrari’s inner core, another important aspect to the 488’s engine program focused on sound. “This was another challenge for us,” adds Leiters with a wry smile. “The turbo is ‘cutting’ – it doesn’t have that naturally aspirated growl, so this engine somehow needed to still have that real Ferrari sound.” So, just like the California T, the 488 unit employs exhaust headers with longer, equal-length tubing. “All of the pipes are the same length, but they are even longer than the pipes in the California T engine – it’s a complex bit of design, but it really works,” adds Leiters, pointing out another engineering difference between the two new V8s.

A flat-plane crankshaft is also used to help get the sound right of the 488, but at the same time, this setup also realizes maximum compactness, lower mass, and improves the engine’s internal fluid dynamics by ensuring equal pulse spacings – and therefore balance between the cylinders

WHO’S IN CHARGE?

Leiters says that the 488’s V8 was always going to be a turbocharged development – a naturally aspirated design was never on the cards. “It was clear that if we wanted to match performance goals with efficiency, the only option we had was to go down the turbocharged route. “So, by using the turbocharger, we have increased performance by 100ps, which is a lot. But a second effect is also the medium performance, so not just on the peak but across all the revs, we’ve managed tremendous output, meaning the overall performance of this car has been increased to an incredible level.” But in keeping with this issue’s cover story, what does all this mean for naturally aspirated creations? “The future of naturally aspirated engines depends on the concept of the car. So, when we talk about our 12-cylinder engine, we want to maintain this engine technology and engine design in those types of cars. But if we want to reach [12-cylinder] power ratios with a V8, it’s clear that we have to go with a turbocharger for the eight-cylinder.”