Difference between Jaguar XJR-9, 10, 11, 12

Does anybody how to spot the difference between these cars? Because to me they look almost completley identical...especially the XJR8 and XJR9LM

http://albumauto.9online.fr/24heuresdumansauto/1987/jaguarxjr8lm_87.jpg
The XJR-8

http://www.team-ninja.com/vbulletin/attachment.php?attachmentid=3685&stc=1&d=1059592064
The XJR-9

What year are these from? Jaguar hasn't been busy with developing racecars for a while, so maybe they were just carryovers but necessary so they could run in LM.

This may help clear things up:
http://www.dailysportscar.com/free/tour/history.htm

Does anybody how to spot the difference between these cars? Because to me they look almost completley identical...especially the XJR8 and XJR9LM
The XJR-9 is an evolution of the XJR8; these cars have the venerable 7l V12. Exhaust position is different on the XJR-9. The XJR-10/11 was the 3l V6 turbocharged successor; XJR-10 was the IMSA GTP version, XJR-11 the Group C car for the World Championship. As the 3.5l Formula 1 style engines became mandatory for Group C, and older cars were severely handicapped as they were phased out, Jag still stuck with the V12 for Le Mans because the newer cars couldn't go the distance. So the XJR-12 was a modified version of the XJR-9, running at 1000kg as opposed to the 800kg it had originally been designed for, and with a 7.5l engine in its final year, 1991.

What year are these from?
XJR-8: 1987
XJR-8: 1988
XJR-10/11: 1989/90
XJR-12: 1990/91
Their successor was the Cosworth F1-engined XJR-14 for 1991. Jag left sportscar racing at the end of that year, Group C/GTP as a whole collapsed a year later.

Jaguar hasn't been busy with developing racecars for a while,
Jaguar didn't develop these, either. They were built by TWR who'd been working with Jag since the 1970s. Jaguar's last self-developped racecar was probably the Le Mans E-Type. No manufacturer develops its own racecars these days, they all outsource to specialist companies. Bob Tullius' Group 44 initially started an IMSA GTP programme with its own chassis in the early 1980s, and the factory picked up on it and entrusted TWR with the development of a Group C car; TWR eventually took over the IMSA programme as well.

oh man, thank you for that...no wonder the XKR12 looked alot like the 9.:smokin:

7.5L V12! thats huge

Interestinly enough, the TWR car's designation time line isn't necessarily linear. You'll notice as much as I've added two cars you didn't inquire about but are interesting (and relevant) nonetheless. There's some overlaps on the years especially in the case of the IMSA cars. For instance the XJR-9 was phased out and the XJR-10 phased in during the 1989 IMSA season. The difference in engine capacities between the IMSA and Group C cars had to do with regulations. Group C's engine formula was essentially free whereas in IMSA they capped both normally aspirated and turbos with a maximum capacity (In general it was 6.5 L for normally aspirated, 3.0 L for turbos).


XJR-8: 1987 & 1988; Group C, 7.0 liter normally aspirated V12. Definitive high downforce (high wing, double element) and low downforce (low wing, single element) configurations.

XJR-9: 1988 & 1989; Group C and IMSA GTP. 7.0 liter V12 in Group C, 6.5 liter in IMSA GTP. Engine intake moved from atop the engine cover to inlets on the side of the engine cover. Definitive high downforce (high wing, double element) and low downforce (low wing, single element) configurations.

XJR-10: 1989-1991; IMSA GTP only, 3.0 liter V6, twin turbo. Same wheelbase as the V12 cars, but with shorter V6 the engine cover was tighter to the car across the same distance.

XJR-11: 1990; Group C only, 3.5 liter V6, twin turbo. Effectively the Group C version of the -10, very similar in appearance and only differences would be circuit specific in addition to slight difference in engine capacity (IMSA rules capped turbos at 3 liters).

XJR-12: 1990-1993; Group C (Le Mans) and IMSA GTP. By 1991, Jaguar had replaced the V12 in both Group C and IMSA GTP with the turbo V6. But TWR optimized the V12 for the endurance races such as Sebring, Le Mans, and Daytona, and the XJR-12 was the go-to chassis for those events (starting in 1990). 7.4 liter V12 in Group C (Le Mans) competition, 6.5 liter V12 in IMSA. Raced at final TWR IMSA GTP race, 1993 Daytona 24. XJR-12 was first Ross Brawn project.

XJR-16: 1991; IMSA GTP only. 3.0 liter V6, twin turbo. Developed by TWR-Valparaiso, effectively an IMSA GTP optimized XJR-10. Much higher downforce. Wheelbase increased 4.3" over XJR-10. Large twin tier rear wing, visually more aggressive than XJR-10.

XJR-14: 1991 & 1992; Group C and IMSA GTP. 3.5 liter V8, normally aspirated. Changing regulations in Europe starting in 1991 led to the design of this car. Won Group C Championship in 1991. When Jaguar pulled out of Group C series for 1992, XJR-14 was raced in IMSA GTP series. First clean-sheet Ross Brawn car, bears little resemblance to preceding Southgate designs.