It was into this environment that the independently designed Allard J2X was born, to much fan-fare.  By 1991, mainstream sports car design bore little resemblance to the Porsche 956s and Lancia LC2s that first debuted some 10 years earlier.  The Allard J2X suddenly accelerated the pace of thinking at a time when the development graph was already quite steep.

But the Allard was a veritable flash in the pan and followed the fate of many racecars by failing to realize its potential.  So what happened to this car and who was behind it?

Chris Humberstone was a designer with a flair for tackling and managing complex engineering projects.  Over the years he had worked at various racing teams and manufacturers, accumulating an interesting resume; Beatrice / Force F1, Benetton, and Brun Technics. In the late 80s Humberstone approached Alan Allard, the son of Sidney Allard, about licensing the family name for a future road car project.  Though delayed a number of years, in the early 90s Humberstone finally formed Allard Holdings with the intent of moving forward.  The Allard name would imply credibility and history to the effort and open doors that may have otherwise remained closed.  Costas Los and Jean-Louis Ricci would eventually come on board with investment capital, also bringing along their own racing contacts, besides the money to help move the project ahead.

Costas Los’ professional background was in business, property, and shipping.  Given his professional racing resume, that can almost be considered his side career. Los has driven everything from the ubiquitous Porsche 962 to the Aston Martin AMR-1 and the Gebhardt Audi.

“Right after my season in Japan, I took a year off and ran into Jean-Louis Ricci who persuaded me to get involved in the Allard project”, says Los.  He, along with Ricci, put up a percentage of the initial startup monies.  Los would then spend the next 24 months concentrating on tracking down additional funding as well as an interested manufacturer.

The Allard team’s intent was to build a customer racecar and also have a road car tie-in, an Allard designed supercar.  The Allard J2 supercar was to have been loosely based upon the J2X Group C chassis, and use a detuned Allard-badged Cosworth DFR.  Though the J2 was a future project to be completed after the J2X was successfully on the track, two Lexus LS400s were modified by Allard (mainly styling, aerodynamics, and interior) and used as lures for potential manufacturer backing for the J2X.  The LS400s were presented to Toyota in hopes that they would be interested in the Allard tie-in, to sell a low-volume exclusive, the Allard LS400.  In fact Toyota did show interest, but confusion amongst the Allard partners led to them being unable to present a clear marketing proposal.  Toyota quickly lost interest.

In the meantime, Humberstone began to bring together a group of young, enthusiastic, if somewhat inexperienced, designers and engineers.  Humberstone approached Hayden Burvill and began forming the core of the design staff, starting in late 1990.  The Australian Burvill became Chief Designer for the J2X: his background was Industrial Design.  Burvill: “ID people bring depth of conceptualization, relative freedom from initial technical or material hurdles, a can-do attitude and confidence towards the creation of ground breaking solutions.  Ultimately the real strength of the J2X project was the ability to move forward without hefty pre-conceptions.”

Burvill’s ID background would play from strength to strength, given the wide-open nature of the Allard’s design brief.

John Iley, the J2X’s aerodynamicist, joined Allard from Brun Technics in early ‘91.  Iley had a hand in the aerodynamic development of the Brun C91 when he was fresh out of university.  “During my final year (of university) I spent a large proportion of my time doing wind tunnel testing and data analysis of a sports prototype.  I was lucky that Chris Humberstone saw this work.  At that stage he was in charge of Brun Technics design in England and he offered me my first job.  I joined as a designer, with emphasis on using my recent aerodynamic studies on their latest 3.5 litre car.”  Humberstone soon left Brun to pursue the Allard project and contacted Iley as things developed.

Both Burvill and Iley were relatively inexperienced when considering the task at hand, but, as Burvill puts it, “Chris Humberstone would not have been able to create this project in the way we did if he had used a more experienced or named designer.  When you consider the time period and the J2X peers, having a highly conceptual novice was kind of prerequisite to achieve what we did with the Allard.”

Not wasting any time, conceptualization for the J2X began in the late months of 1990.  “We had seen people do maximum cross section for chassis stiffness (Brun C91) and we knew about the XJR-14 being very low profile.  Our approach was to optimize the package to allow maximum volumes for investigating the aero solution,” says Burvill.  John Iley adds, “you always look for targets, areas for improvement, areas of strength with existing designs, ways to get the most from the category’s regulations...there is also the difficulty of striking the right balance during development of very original new concepts, versus iterative steps”.

The primary goal was minimal frontal area, and the J2X’s radical look was the result.  1/10 scale study models were built to evaluate ideas, with Burvill and Humberstone contributing; Iley joined the project a few months later.

What began to emerge combined the best of all elements - narrow tub and bubble canopy, detached front fenders, front wing, and very low profile rear bodywork.  Two 1/3 scale wind tunnel model spines were used to evaluate as many ideas as possible.  It would have been preferred to use the Imperial College wind tunnel in London, but McLaren was the favored customer and there wasn’t any tunnel time available for the Allard group.  Clearly the J2X concepts were unlike anything that was racing, and there was some question if they would produce results in the wind tunnel.  The MIRA wind tunnel in Warwickshire, England, was chosen and testing began in earnest. 
Iley:  “We tested in regular short and intensive three-day test sessions, starting from the very first test with the radical minimal layout, to see if we could get it to work.  It showed sufficient promise to persevere, with gradual improvements being made test by test, to produce a strong, distinctive and legal aero platform.”

Sports cars have historically been hampered by a lack of front grip.  The design goal has always been to dial in as much front grip as possible to reduce or eliminate the car’s understeer without affecting airflow to the rear wing.  In the past, front wings were tried on sports cars with the results being less than satisfactory.  Typically the front wing element spoiled the airflow to the rear wing, which, ironically, produced the desired result, a forward balance shift, but was ultimately detrimental to overall downforce, but especially at the rear.  The J2X’s complex front wing, with its large secondary flaps situated between the front fenders, was squarely aimed at eliminating the historical sportscar understeer condition.

Both Iley and Burvill indicate that the front wing of the Allard J2X functioned in and of itself and had little impact on the continuing airflow to the rear wing.  Burvill:  “The front wing definitely worked in isolation.  The impressive L/D figure would not have been achievable otherwise. What you cannot see is some quite sophisticated air management under the nose.”  The J2X featured a raised front nose section that allowed for air to flow onto the top surfaces of the floor just aft of the front wheels.  Burvill continues:  “This air was then managed rearward over the extremely low profile rear deck.  This was to make the rear wing work harder, not suffer.”

Additionally, the front wing flaps performed a rules compliance function by masking the suspension components, as seen from the front.  John Iley says, “The launch version of the car, which was in a maximum downforce configuration, had probably about ten settings, the problem being to keep the suspension covered in elevation at the same time.”  The rules function of the front wing flap did limit its amount of travel somewhat, in that at lower flap angles it would have been possible for suspension components to be seen (hence, rendering the car illegal), but within the practical range of flap angle vs. balance, it was not an immediate issue.

Interestingly enough, additional front downforce could have been dialed in by adjustments made at the rear of the car.  The twin-tier rear wing, with one double element wing running low and in conjunction with the tunnel exit, and the other running high at cockpit height or better, was found to be a powerful device to tune aerodynamic balance front and rear.  Iley: “With a wheelbase of 2850mm and the mandated Group C 900mm flat floor area forward within this, the onset point for the diffuser, its main load center, was in the forward portion of the wheelbase.  The interaction of the lower wing with the diffuser was such, thanks to a very low rear deck, that increasing the flap angle on this lower wing improved the diffuser performance and actually gave more front aero balance.”  The J2X could carry a maximum of 43% front aero load.

As mentioned, the achievement of the ultra low rear deck height of the Allard was driven by the desire to feed the rear wings with airflow as unobstructed as possible.  Additionally, the exhaust gas was piped into the trailing edge of the tunnel exit, but for a purpose other than aerodynamic.

Iley:  “As a rule I am not a supporter of such a system (exhaust activated diffuser) as it makes the car’s performance too throttle dependant, which does not provide the basis for a stable platform.  However the location on the J2X Allard was far enough rearward that its effect was greatly reduced.  The main drive to route the exhausts this way on J2X was just to achieve an incredibly low and tidy rear deck for the lower rear wing, not to utilize a blown diffuser principle.”  Ultimately the designers were able to achieve a rear deck height only some 10 mm above the rear tunnel exit.

According to John Iley, the J2X developed approximately 5500 lbs. of downforce for 916 lbs. of drag at 150 mph (L/D 6.0:1).  “Yes our loads were huge and what little correlation work we did to the tunnel numbers seemed to agree with them well.”  Fifty-five hundred pounds equates to a theoretical 9778 lbs. of downforce at 200 mph.  Peak downforce was achieved at a 35mm front ride height and a 48mm rear ride height, with good high ride height performance and low overall pitch sensitivity.  With only some 560-580 horsepower on tap from its 3.5 liter Ford DFR, a low downforce package would have eventually been developed, though it was clear that a more powerful engine would have greatly benefited the project.

With such high aerodynamic downforce, a power steering system was also deemed a necessity, though never developed or installed.  Eventually the front suspension would have required reworking to allow for the fitment of such a system so it became a future project.  A simple active suspension system was installed for the J2X’s testing, though never optimized.

The Allard’s monocoque was a unique, full-length structure, incorporating a rear composite chassis that housed the gearbox. The rear chassis was designed so that the gearbox could be swiveled within the structure to allow for easy change of the gear cluster.  The entire tub, minus the gearbox sub structure, but including the FIA mandated steel roll over hoop, weighed around 85 kgs.  The full-length tub allowed for the potential installation of various customer engines, which were anticipated to be used by IMSA competitors.  Additionally, it was extremely stiff, some 80,000 lbs./deg.

Burvill:  “The chassis comprised a closed box section 100mm wide on each side, running the full length of the footbox and sills.  The roll hoop could not be fully integrated or made of anything but certified diameter and wall thickness steel, unless we had subjected the tub to a potentially destructive crash test.  We had the roll hoop inspected and then bolted and bonded it into the chassis before the top section of the chassis was bonded - so it did become fully integrated.”

Unfortunately the rear composite chassis turned out to be a potential liability, compromised by the use of an off the shelf gearbox (Leyton-March).  According to Paul Burgess, detail designer engineer for the J2X’s rear chassis, the design was, “constrained by using an existing single seat gearbox with integral rocker and suspension mounts, it was complicated to mount and access the gearbox internals. A much neater solution would have been to design and build a separate and easily changed gearbox, without any suspension mounts on it.”  On track testing would later bear out the need to rethink the gearbox housing, if not the need redesign it.

Interestingly enough, the entire Allard J2X was drawn by hand.  Hayden Burvill again:  “The car was drawn on a five meter drawing board, and all the body sections were faired by traditional lofting techniques.  The pattern makers had a real challenge with some of the parts, particularly as the drawings were often quite Spartan and allowed for ‘PMB’, Pattern Makers Blend.”