Saturday, January 30, 2010

Ferrari 458 Italia technical highlights


The technical aspects of the Ferrari 458 production car are fascinating and surprising. There are multiple articles about the car but a summary is in order due to the sheer amount of notable achievements . There are very few cars with such innovation. Read further, you'll be surprised.

The aluminum chassis (frame) is 20% stiffer in it's torsional rigidity (resistance to twist) than it's predecessor, the incredible F430. Also 8% stiffer in resistance to bending. This was done without any weight penalty despite the wheelbase growing 1.4". This means that the suspension is better able to do it's job without geometric compromises that it are not', and can't, be designed for. It also means greater stability than the F430 without a weight penalty.

Among multiple aerodynamic enhancements, downforce is higher, up to 794lbs at 200mph and matches the weight distribution of 49% front and 51% rear. Road & Track states 58% rear. Odd. The benefit regardless like an upside down airplane wing, the car is pressed down to the road instead of lifting off. This allows for for higher cornering speeds and greater stability.

The front winglets in the fascia are aerolastic and route air upward into the radiators and supposedly contribute to the downforce. But at over 124mph, they deflect downward by up to .8" to re-route the air and reduce drag. The overall drag coefficient drops from .343 to .330 as well. The other factor however is frontal area. The frontal area is multiplied by the coefficient of drag (cd) to get the true measurement of resistance.

The dual plenum intake manifold has four modes of variable resonance using sonic waves to force air into the combustion chamber called "resonance supercharging." This is creates up to 30ft lbs of torque. All these increases in power and torque and the fuel consumption improves 13% vs. the 490hp F430. The carbon dioxide output is supposed to be best in class as well. 307g/km or 1.09lb/mi if you're keeping track.

The engine is the highest revving production V-8 in the world with a 9,000rpm redline. Reportedly it will upshift automatically at redline with the dual clutch transmission. It produces 557hp per Motor Trend, 565hp per R&T and 562hp per Car & Driver. Either way, it's from 4499cc or just a hair under 4.5 liters and at 200mph there is a 5hp ram air effect from the air intakes in the C-pillar vents.

Oddly, the main air intake for the engine bay, per Road & Track ,is from underneath the car. Assuming this means the radiator(s), it seems odd to me because of the sheer amount of dust and debris from the road. Don't think there is much? If you've ever seen a motorcycle with downward pointing pipes blip the throttle you'll see little dust clouds. In this case, it isn't just airflow past components, it's air intake. I'll be very curious to know how that is managed, if there is a suggested maintenance interval and what that interval actually is.

Below 3000rpm at wide open throttle, 20-30% of the required fuel is injected at 40 degrees past bottom-dead-center of the piston, creating a rich zone which increases torque by up to 6%. Is this a standard technique or if it's new and what is required to make it work such as piston size or speed. Otherwise, should all those dyno-tuned cars go back for updates?

Thanks to the cooling effect of high pressure direct injection, among other advancements, the compression ratio is 12.5 to 1. Looking for a comparison, the horsepower and compression ratio are quite close to the famed 427cubic inch L-88 Corvette engine from '67 to '69. And its also about 1/3rd smaller at nearly 275 cubic inches and revs roughly 1/3rd higher.

Nearly 6ft lbs of torque is saved at 2500rpm by 3 separate crankcase oil scavenger pumps thaIt prevent air from flowing between the galleries creating a near vacuum. The middle 2 cylinders on each bank move out of phase with the other middle two which is the classic flat-plane crank design.

6hp is saved at 9000rpm and 2% fuel consumption at 105mph due to a variable geometry oil pump.

The 3-tip center exhaust isn't for show. The center outlet is used for most driving situations, but the outer two open depending upon driver settings on the manettino steering wheel dial with wide-open throttle and reduce backpressure from 7.3 to 5psi.

The Engine Control Unit (ECU), monitors each combustion chamber result by monitoring ionization across the spark plug gap. This is only done in the F430 Scuderia and Ferrari FXX. I wouldn't be surprised if it also is done in the 599XX. Does this require additional hardware, an upgraded chipset or just additional code? In other words, why is a necessity or what is the benefit? How much does it add to the cost?

The second dual-clutch transmission offered by Ferrari shares 70% of the content including the clutches with the model with the first, the California. Developed by Getrag, top speed is purposely achieved in 7th gear. This means all 7 gears are usable from a performance standpoint. Many cars, whether 5 or even 8 speeds, the top 1 or 2 gears are for fuel economy reasons only.

The time between shifts is reported to be .04 seconds. One would assume there should be no gap if one clutch engages while the other disengages but hopefully explanations will be down the road as DCTs become even more prevalent.

Another feature of the DCT is holding the left paddle in for rapid-fire downshifts while braking such as when approaching a turn. The intent is to choose the best gear for power out of the turn and allowing the driver to concentrate on steering and braking inputs. Although technically another driver aid, it's use is optional.

A limited-slip differential called E-diff3 is supposed to enable corner exit acceleration 32% greater than the F430 before it and with 28% less countersteering. This is a radical difference in philosophy than McLaren's MP4-12C which does not have an LSD.

The 458 also has magnetorheological shocks developed by Delphi. The ride control is assessed every millisecond and damping rates adjusted within every 8 milliseconds. The Corvette ZR1 and Ferrari 599GTB are two other super high performance cars equipped as such. The latest generation of these shocks have 35% less internal friction for a more comfortable ride over small bumps.

The steering is ratio is a super quick 11.9:1 vs. the F430 Scuderia 16.9:1. That is a vast difference vs. what is already a track-ready car. So no shuffling of the steering wheel or hand-over-hand motions in turns.

There is a tire, engine and brake temperature readout. This is done without sensors, but rather based on algorithms. Ferrari was already a step ahead of me when I published this idea on September 6, 2009. This means the driver knows not only when to "beat" on the car, but if the tires will be more likely to spin or slip.. The brake temperature indicator is interesting considering the car already has huge carbon-ceramic rotors.

The 1:25 lap time at the Fiorano test track is the same as the less powerful, automated single-clutch yet lighter F430 Scuderia on competition rubber. The 458 Italia did it on Michelin Pilot Sports. The Enzo is also quoted at 1:25 as well.

The weight is listed at 3,274lbs in R&T (most likely with a full tank) and Ferrari shows 3042lbs with forged wheels and racing seats. Sometimes racing seats are not available in the US due to safety regulations and airbag compatibility. Compare this to the F430 Scuderia which is listed as weighing anywhere from 2,756lbs (bone dry?), 2975lbs (wet?) to 3,150lbs (US spec, full tank).

The Ferrari 458 Italia has features that few, if any automobiles have on the road today. Despite drivers' aids that make a driver faster, but not necessarily better, it is quite possibly the finest sports car on the road.
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