For the 1985 season, Bob Tulius and Group 44 racing modified their XJR IMSA contender with a Kevlar-reinforced chassis and updated aero.

Two cars driven the teams of Redman / Haywood and Tullius / Robinson were always in contention but didn’t score a first overall until the season closer at the 3 Hour Daytona Finale.

Group 44 continued with the cars less aggressively in 1987, but scored first overalls at the 300km of Laguna Seca and 3 Hours West Palm Beach.

type	Racing Car
production years	1983 – 1985
built at	USA
body stylist	Lee Dykstra
coachbuilder	Group 44
production	5
engine	60º V12
position	Front Longitudinal
aspiration	Natural
block material	Aluminum Alloy
valvetrain	SOHC, 2 Valves per cylinder
fuel feed	6 Weber Carburetors
displacement	5955 cc / 363.40 in³
bore	91.9 mm / 3.6 in
stroke	74.9 mm / 2.9 in
compression	12.2:1
power	484.7 kw / 650 bhp @ 7500 rpm
specific output	109.15 bhp per litre
bhp/weight	698.92 bhp per tonne
torque	650.8 nm / 480 ft lbs @ 6000 rpm
body / frame	Aluminum Tub Chassis
driven wheels	RWD
steering	Rack & Pinion
f suspension	Double Wishbones
r suspension	Double Wishbones
curb weight	930 kg / 2051 lbs
wheelbase	2591 mm / 102.0 in
front track	1676 mm / 66.0 in
rear track	1600 mm / 63.0 in
length	4547 mm / 179.0 in
width	2007 mm / 79.0 in
height	1003 mm / 39.5 in
transmission	5-Speed Manual
top speed	~349.15 kph