Just like the other two now-established members of the J-series range, the integral theme of the Autodelta 159 J4 2.2 C is to continue a long standing tradition of applying forced induction principles to develop nothing less than the very ultimate expression of high performance motoring. The Autodelta 159 J4 2.2 C once again makes strides across the sphere of engineering excellence, and applies the results of an intensive 18 month research and development programme, led by Head of R&D Sergio Truzzi, to Alfa Romeo’s advanced direct injection JTS, making us the only company in the world to develop a forced induction solution for this power unit.
With the commercialisation of the supercharged Alfa 159 2.2 JTS we have taken a dual approach, offering two solutions to satisfy all demands. The excellent all-round capabilities of the Alfa 159 architecture blossom into life when harnessed to our new supercharging upgrade. As such we are offering the 159 2.2 C supercharged package at this level, commercialised at a highly competitive price, and for the many customers who will desire to maximise the dynamics and performance of the car, we have developed the usual enhancements – to the driveable edge – in every area, which will be offered as the J4 2.2 C option. Thus the driver has two choices; he can experience full Autodelta performance wrought to the 159 at an affordable price, or take his car to the ultimate limit in every department by choosing the full range of options that suit his driving requirements. As usual though each Autodelta car will be built uniquely, with every customer’s individual demands met and exceeded by our engineers – a challenge we always thrive on, and never fail to meet. Although the J4′s 0-100 km/h sprint is more rapid now, one of its more capable abilities of this sports saloon is the in-gear acceleration and flexibility which will impress those who get behind the wheel.
What we have created is a car to satisfy even the most demanding of drivers, a car that simply immerses you in its stunning dynamic capabilities, and that allows you to experience everything that Alfa Romeo has built its historic brand values on. But true to our tradition, and to satisfy our customers’ requirements, this is also a practical ‘user-friendly’ sports saloon that is just as driveable in the morning traffic jam as it is when let off the leash on one of Europe’s finest roads.
Alfa Romeo’s history is littered with fabulous, ground breaking sports cars that have reshaped automotive thinking time and time again. As such when seeking inspiration the possibilities are virtually unlimited for our team. However for with this project one car stood out especially, and so with the 159 J4 2.2 project Autodelta really wanted to capture the modern day spirit of the Alfa 156 GTA, one of the most revered ‘hot saloons’ of the decade, and a sports car that we have enjoyed rewarding success in tuning. This evocative car was a benchmark for us, however seeking more refined comfort and improved, updated dynamic behaviour.
Supercharging Alfa Romeo tradition and a offers the ultimate performance solution
Under the sleek, swaged bonnet of the Autodelta 159 J4 2.2 C beats the muscular heart of this powerhouse: a supercharged version of Alfa Romeo’s impressive 2.2 JTS direct injection petrol engine, the first production application of forced induction to this robust engine. The incorporation of the Rotrex C30-74 supercharger and a specifically-developed bespoke system boosts the 2.2-litre unit’s maximum power from the standard 185bhp up to 245 bhp, an increase of 60 bhp. Meanwhile, peak torque is raised from 230 Nm to 290Nm, giving the vibrant sports saloon an extra 60 Nm of torque.
Supercharging the 2.2 JTS engine and evolving the 159 J4 2.2 C package to perfection has been a long-term project for Autodelta, running alongside the development programmes to realise the J5 and J6. Autodelta’s engineering team was able to build on valuable experience gained when it became the first company in the world to apply forced induction to Alfa Romeo’s 2.0 JTS unit, as used in the 156 and GT models; and although it is an all-new unit in the Alfa 159, many of the important lessons learnt, and technical knowledge gained, were carried forward to the 2.2 JTS project.
Redesigned intake system – to improve response and driveability
The 159 J4 2.2 C features a completely new aluminium inlet manifold as the factory OE plastic unit isn’t able to operate with the 0.65 bar boost level which the Rotrex C30-74 unit produces. The new inlet manifold design, now with a reduced volume, was also a critical component to increase the speed of response. Changes to the inlet and exhaust camshaft variator control strategy had to be evolved to generate more continuous torque and improve driveability.
NGK Iridium IX – applying the latest ignition technology to improve combustion efficiency
Autodelta engineers’ have adopted cutting-edge NGK Iridium IX spark plugs as OE for the 2.2 C for the all round advancements they offer and specifically because a colder heat range spark plug was necessary. Recent fabrication advances have allowed Iridium, a very hard precious metal, to be incorporated into the construction of spark plugs through the use of laser welding technology. Iridium has a melting point of 2450 degrees, considerably higher than platinum, and its strength is approximately 8 times of platinum offering considerable advantage over the plugs used as OE in the JTS engines while the more efficient spark optimises the ignition/combustion process, leading to improved fuel economy, increased power and acceleration and improved throttle response. The properties of Iridium mean that a much smaller electrode tip can be used, allowing a reduction in ‘spark jump’ voltage, and thus improving and reducing strain on the ignition system. NGK found minimal degradation of the Iridium IX occurs during its user life and extensive testing by Autodelta’s engineers within the specific scenario of the J4 2.2 C project also found this to be the case and we are happy that there is no measurable drop off in performance up to 12,000 miles, the use life that both NGK and Autodelta will recommend.
ECU – pumping up the electronic ‘heart’ of the car
Throughout the J4 development process one of the key factors was the programming of the ECU (Engine Control Unit), and more than twenty five different files were written and thoroughly tested during the process. Control of the Lambda as well as continuous cam variator characteristics were optimised to improve driveability and throttle behaviour. All the safety perimeters managed by the ECU to avoid any possible engine damage which are in default place had to be in full operation and revised to a more critical level. The ECU will operate in safety mode once it detects an error in the operating system and avoids any possible damage in the engine internals by going into safety mode which allows the car to be driven slowly to a dealer for diagnosis. As with the J5 and J6, it was very important to factor in the reliability and safety of the 2.2 JTS engine. Our engineers’ programming skills allowed the engine ECU set up to be optimised and maintained to continue reliable performance even in extreme conditions. The optimised engine ECU and all other linked ECU’s are also in line with EOBD2 actual diagnostic rules, and can be tested with normal tools available at dealer workshops and other universal testers.
Limited slip differential: key component to any Autodelta product
Autodelta first introduced a limited slip differential (LSD) working on the front wheels with the 147 3.7 GTA AM model almost half a decade ago; and the experienced gained from this now iconic Autodelta model has been passed on to the J4 project; as the new model now has a mechanical LSD. This LSD also importantly contributes to safer driving, allowing safer acceleration and cornering, even when there are drastically different grips levels under at each tyre. And at the same time we fulfil our mission to further improve the driver’s experience.
Enhancing platform dynamics to complement the power increase
The chassis dynamics have been re-worked to provide optimum handling and ability to use the additional power without any form of compromise, incorporating all-new dampers and springs. The J4 2.2 C draws from the experience gained during the realisation of the J5 3.2 C and J6 3.2 C, which share similar platforms. With carefully chosen damper and spring rates and with new geometry settings to suit the character of the new Limited Slip Differential the driver has extra confidence to exploit the full power delivered by the Rotrex supercharger. The development of these J5 and J6 projects involved demanding running on race tracks such as Silverstone, Spa-Francorchamps and the Nürburgring. The fully adjustable coil over suspension set-up allows for height adjustment as well as bound and rebound adjustment to enable the driver to fine tune the car for any occasion.
Evolution to optimise the braking window
The J4 2.2 C features uprated brake discs, which are additionally perforated at the front and rear, and new special compounds brake pads. These combine to improve all-round braking performance, allowing the discs and pads to operate during the most demanding of driving scenarios, to much higher temperatures, and to offer a greatly improved braking window.
Exuding the legendary Alfa Romeo ‘sound’
When an Alfa Romeo drives past the bystander can recognise its heritage even if their eyes are shut, so integral a part of the brand’s long tradition is the sound that its racy engines emit. Autodelta always adhere to this Alfa Romeo tradition and getting the right exhaust note is fundamental. The J4 2.2 C’s exhaust system, with its stainless steel silencers and Autodelta ‘trademark’ quad oval tail pipe exits, has been designed to enhance the engine’s sound. The result is a cacophony of music to the ears of the ‘Alfisti’.
No compromise in the search for optimal grip
Developing perfect road adhesion is another critical component in the J4 project. Thankfully Autodelta can turn to its tyre partner Dunlop to seamlessly undertake this task, and draw on an intensive development programme for the J5 and J6. After an evaluation process carried out at the Dunlop Development Centre in Hanau, Germany, in conjunction with Autodelta, the latest Dunlop ultra high performance pattern SP Sport Maxx GT compound was selected, and the J4 2.2 C will signify the first time that this new 245/35 ZR19 XL tyre has been applied to a production vehicle, signifying the high regard that the leading global tyre manufacturer holds for Autodelta. This tyre will enter production in August 2008.
The new compound of the Dunlop SP Sport Maxx GT also importantly pushes forward the environmental credentials of the tyre range. The tyre will feature a combined silica/black carbon compound. The silica comprises of the latest technology high dispersion silica combined with state-of-the-art functionalised polymers and traction resin. The black carbon is a special type derived from the DTM racing tyres. Aromatic oil free assures that the tyres will even comply with all foreseen new environmental regulations beyond 31.12.2009. This new pattern on the Dunlop SP Sport Maxx GT, as applied to the Autodelta J4 2.2 C, offers all of Dunlop’s highly regarded “feel the road – touch technology”: Multi-Radius Tread technology, which provides highly effective pressure deployment in the contact patch combined with a smoother transition from straight line to curve; flatter tread profile, with about 8 % bigger contact patch, in order to achieve higher stability and steering precision combined with more grip; and specific bead seat system providing a tight link between tyre and rim essential for enhanced road feedback.
Advanced technology wheels are fundamental to overall weight saving
The Dunlop SP Sport Maxx GT tyres will be fitted to wheels supplied by OZ Wheels. OZ Wheels are an Official Technical Partner of Autodelta and all our bespoke models use wheels which have been developed by OZ for the specific requirements. For the J4 2.2 C we chose – in conjunction with OZ – the 19-in Botticelli HLT which is manufactured using cutting-edge flow forming technology. The result is a ground-breaking wheel that is up to 40 percent lighter than alternatives. It offers a drastic improvement in power/weight ratio, a reduction in unsprung mass and in the braking performance window; and faster acceleration.
The Botticelli HLT 19-inch wheel from OZ has been highly successful and is officially approved by the Renault F1 team. A ground breaking new process in wheel development, it offers excellent technical features, that result a lower weight than for wheels cast in forged aluminium. The reduction is evenly distributed on each wheel, improving unsprung weight. It thus emphasises the effect of a design directly derived from experience in competitions in which the weight plays an important role in both performances and safety. Constructed according to Flow Forming Technology, the Botticelli 19″ has very similar mechanical characteristics to those of a forged wheel, confirming the attainment of two very important goals: weight reduction and firmness.
Weight saving – integral to the development programme
Saving weight is always at the forefront of our engineers’ minds and each new component is designed to offset weight. The alloy bodied Rotrex supercharger weighs just 7 kgs and the whole system features lightweight components throughout: the intercooler and inlet manifold are both aluminium. The aerodynamic kit is developed to be ultra-light without compromising toughness and durability, while significant weight is saved by the OZ Wheels. Further kilogrammes are chipped away by the new exhaust system and suspension components. Thus, although the J4 features a new supercharger system, the J4 is an overall 5 kg lighter than the standard production Alfa 159 2.2 JTS.
Styling – motorsport derived aerodynamics blended with Autodelta unique DNA
The styling aspect takes on an important new direction compared to the recent J5 and J6 models. The project, as is usual, focused on aerodynamic demands coupled with the requirements of the greater airflow into the engine bay. The result is a sports accessory kit that includes front splitter, rear apron and side skirts, with the front and rear apron sections designed to fit the standard bumpers of the production Alfa 159.
The Alfa 159 presents a much loved form and our design process had to complement this superb work from Giorgetto Giugiaro, building on the foundations that the legendary designer had styled.
As is historically typical with Alfa Romeo production cars, design inspiration follows the latest trends of aerodynamics in motorsport. For this approach our designers underlined the historic Autodelta philosophy of “today’s racing car for the road tomorrow”. The inspiration from motorsport concludes with the integration of “flicks” on either side of the splitter. The form of the flicks was integrated in a manner that suited the styling of the Alfa 159, closely following the lines flowing from the traditional Alfa Romeo grille. The result is a dynamic and thrusting stance that also emphasises the engineering applied to the suspension and braking characteristics of the Autodelta J4 model. The integration of the flicks as a spoiler also refers to historical Alfa Romeo models that used dominant front spoiler treatment in motorsport, such as the Autodelta Montreal and the Alfetta GTV8. The expression which is gained from the aerodynamic treatment can also be compared to the “eyebrows” above the headlights of the Giulia Berlina – a car which was “designed by the wind” and represented the backbone for the original Autodelta models of the 1960s.
At the rear we see a continuation of the diffuser style first seen on the Autodelta 147 GTA AM, and now a feature of all Autodelta models. The result is a logical evolution, playing with a contrast between subtle details and a freshly defined diffuser.
Both the front and rear skirts are visually joined in the centre of the car by specifically designed side skirts. The skirts continue the lines starting from the front splitter and bridge them to their endpoint at the exhaust terminals on the rear apron. This is a logical and graphically strong solution, which has resulted in a clear visual connection between the individual components of the J4 styling package. The side skirts closely follow the form introduced on the Autodelta Brera J5 MY2008, and also evolve the typical Alfa Romeo side skirt design that was first used on the Alfa 75 Turbo touring models.
Partners – drawing on technical excellence key area by key area
Autodelta’s strength lies in having a close working relationship with its official partners, who assist in the Research & Development programme of each bespoke mode in their specialist field, thus guaranteeing maximum leverage in the pursuit of optimum performance within each technical area. The J4 2.2 C is no different and key partners include Dunlop (tyres), OZ (wheels), Rotrex (superchargers) and KesselsGranger Design Works (styling). Meanwhile, Mangoletsi, the UK’s largest and longest–established authorised Alfa Romeo dealership, is ‘Official Supplier’ of the cars for our Research & Development programme.