Guide: Nissan R390 Long Tail
Background
After their disappointing run at Le Mans in 1997, TWR and Nissan pledged to return in 1998 with an uprated R390: more speed and improved reliability was the order of the day.
The R390 programme had begun in September 1996 when Nissan contracted TWR to create and race a GT1 car at the Le Mans 24 Hours in 1997 and 1998.
By the time the R390 was ready, Porsche and Mercedes-Benz had both muscled in on the GT1 class with machinery that paid only lip service to the rules as this was supposedly a category for road-going production cars.
The 911 GT1 and CLK GTR moved the goalposts in GT1 and, to some extent, Nissan followed suit with the R390.
However, unlike those German machines, Nissan’s R390 was originally designed as a road car and then transformed into a racer. By contrast, Porsche and Mercedes built fully fledged competition cars that were then reverse engineered to make them street legal.
In addition to Porsche and Mercedes, both of whom spent heavily to further improve their cars for 1998, Toyota were also developing a scratch built GT1 car for Le Mans.
TWR and Nissan would therefore have their work cut out to catapult the R390 into the fastest GT1 challenger.
TWR began their 1998 Le Mans programme in mid November of 1997 with a shakedown test at Donington. Jorg Muller and John Nielsen were on driving duty. The R390 had been equipped with an improved Xtrac gearbox and an updated ABS system.
At the end of the month, nine drivers were present for a series of 24 hour tests at Mugello followed by more of the same at Barcelona in the middle of January.
In early March, Nissan announced that their 1998 Le Mans programme would be expanded to a four car entry.
Two weeks, later the uprated R390 Long Tail emerged for its debut test at Monza.
Bodywork
Most obviously new was the 1998 variant’s extended rear bodywork; this brought both aerodynamic benefits and enabled the R390 to better accommodate the air tight 125-litre luggage area demanded by the regulations.
It had been the Le Mans organiser’s insistence on this luggage rule being respected that forced a late redesign of the original R390 after pre-qualifying in 1997.
A subsequent lack of testing before the 24 Hours meant TWR were unaware that re-routing the exhaust to free up luggage space would cause the solder that held the oil cooler together to melt. This proved a problem that could not be overcome during the race.
To homologate the revised Long Tail bodywork, TWR had to produce at least one similarly updated R390 road car. Accordingly, the original red street version constructed in 1997 was fully rebuilt to the latest configuration.
The extended rear bodywork had a cleaner aerodynamic profile than before and added 140mm to the R390’s overall length.
A reworked tail fascia was shrouded from above by an integral full width spoiler. The four main light clusters were mounted on distinctive cylindrical pods.
For the road version, single exhausts per side were located in each corner of the tail fascia. These were re-routed to become side exiting pipes for the racer.
Four large vents on the tail fascia improved cooling and an updated rear diffuser increased downforce.
Elsewhere, the bodywork was little changed: a pair of NACA ducts were carved out from the front lid and the sills were cut away behind each front wheel.
The revamped road car was painted dark blue and variously ran the registration numbers N15 MOB and R390 NIS. Nissan once again raised the possibility of building customer versions at $1m apiece, but none were sold.
As in 1997, the racing version was equipped with a deeper front spoiler, additional spot lights, a rear wing mounted on twin central pylons and the smallest possible wing mirrors.
Chassis
The R390’s modified carbonfibre monocoque from the Jaguar XJR-15 was unchanged.
Suspension was via double wishbones at all four corners with inboard shocks and coil springs. Spring rates in the road-going version were softer than the race car and ride height was raised by about an inch. Anti-roll bars were installed at either end.
AP Racing supplied the ventilated 14-inch carbon brake discs and six piston calipers.
An improved ABS system was fitted along with switchable traction control and non power-assisted rack-and-pinion steering.
The road car got new BBS twin spoke wheels that measured 18 x 8-inches at the front and 19 x 10.5-inches at the rear.
BBS wheels were also used for the racing version (11 x 18 front / 13 x 18 rear).
All were of the centre-lock variety and shod with Bridgestone tyres.
Engine / Gearbox
Having chosen to resurrect the VRH35Z engine from Nissan’s Group C programme, the R390’s revamped VRH35L version was uprated from 641bhp in 1997 to ‘over 650bhp’ for 1998.
Once again, the road-going unit was quoted as producing 550bhp at 6800rpm with a torque rating of 470lb-ft at 4400rpm.
Twin turbocharged with dual overhead camshafts, four valve light alloy cylinder heads and a magnesium alloy block, this 3.5-litre 90° V8 displaced 3495cc thanks to a bore and stroke of 85mm and 77mm respectively.
Compression was 9.0:1 and there was electronic fuel-injection and twin IHI turbochargers.
Both variants used an updated transversely mounted Xtrac six-speed sequential gearbox and limited-slip differential.
1998 Le Mans Pre-Qualifying
1998 Le Mans Pre-Qualifying took place over the weekend of May 2nd and 3rd.
Nissan returned to la Sarthe with a three car team. They also loaned another chassis (R1) to Nova Engineering. This car would be driven by Mauro Martini and Satoshi Motoyama.
As for the trio of brand new cars, chassis R6 was on hand for Erik Comas / Jan Lammers / Andrea Montermini, chassis R7 for Kazuyoshi Hoshino / Aguri Suzuki and chassis R8 for Franck Lagorce / John Nielsen.
Other works GT1 teams present included a three car outfit from Toyota (GT One), a pair of revamped Porsches (911 GT1-98) and two of the further uprated Mercedes CLKs that were now in LM trim.
Despite the revisions made to the R390 since 1997, lap times appeared to suggest Nissan had been leapfrogged by the latest generation of cars from their rivals.
Fastest overall time went to one of the Porsches. Toyota were second, Mercedes third, Porsche fourth and Toyota fifth.
Quickest of the R390 Long Tails was chassis R6 of Comas / Lammers / Montermini which was three seconds off the pace in sixth overall. Chassis R8 (Lagorce / Nielsen) was seventh and R7 (Hoshino / Suzuki) eighth.
The quickest LMP1 entry was the JMB Ferrari 333 SP in ninth, which demonstrated just how rapidly the GT1 cars had evolved over the previous couple of years.
Chassis R1, driven by Martini / Motoyama, was 16th overall and twelfth in the GT1 class.
1998 Le Mans 24 Hours
After a final shakedown test at Donington in late May, the R390 Long Tails were trucked down to Le Mans for the annual 24 Hour race which was held over the weekend of June 6th and 7th.
Having attended Pre-Qualifying in a plain light blue colour scheme, the three works cars arrived wearing a light blue and white chequered livery.
Chassis R6, R7 and R8 were handled by TWR and chassis R1 was campaigned by Nova Engineering who ran their car in a green and silver colour scheme.
Pole position went to Mercedes with Toyota second, another Mercedes in third followed by the pair of Porsche 911 GT1-98s in fourth and fifth.
The Nissans were tenth (chassis R8: John Nielsen / Franck Lagorce / Michael Krumm), 13th (chassis R6: Jan Lammers / Erik Comas / Andrea Montermini), 14th (chassis R7: Kazuyoshi Hoshino / Aguri Suzuki / Masahiko Kageyama) and 19th (chassis R1: Masami Kageyama / Satoshi Motoyama / Takuya Kurosawa).
Despite having been eclipsed by the latest GT1 cars in terms of single lap pace, reliability proved the strong suit of the R390s in 1998.
By the third hour, all three TWR cars were running in the top ten.
Thereafter, only minor problems for the European-driven cars hampered progress.
By contrast, the Hoshino / Suzuki / Kageyama entry (R7) ran faultlessly to finish third overall and become the first all-Japanese crewed car to claim a podium at Le Mans.
Nielsen / Lagorce / Krumm placed fifth overall in chassis R8 with Lammers / Comas / Montermini sixth in R6.
The semi-works Nova entry finished a delayed tenth overall.
First and second positions went to the works Porsche 911 GT1-98s.
Post Le Mans
Although the R390 failed to deliver the Le Mans victory Nissan desired, the 1998 result went some way to rectifying the disappointment of 1997.
After 1998, the Le Mans rules were changed and the GT1 class was abandoned because, what had started as a category for genuine production models, had effectively morphed into pure prototype racing.
With Nismo and G-Force Technologies in England, Nissan developed the unsuccessful LMP-class R391 for 1999.
By early 2000, Nissan had abandoned sports car racing altogether. The firm instead decided to focus their attention solely on the Japanese GT Championship.
Text copyright: Supercar Nostalgia
Photo copyright: Nissan - https://www.nissan-global.com
