Roll Cages for modern GT cars

These cars do not always have the separate chassis of the classic GTs so strong points in the monocoque need to be found and/or reinforced.

	General work to refurbish original Ford GT40 chassis number 5. Specifically to install roll bar not present in original specification.
	Original chassis plate
	Although the standard Mclaren F1 is a three seat car the GTR variant for racing retains only the central driver's seat. The standard roll cage uses part of the space normally allowed for passengers. The current owner of this car wanted to be able to carry passengers occasionally and to be able to race. The right hand seat  space is taken up with electronics which could not easily be moved so ARRC were tasked with designing a new cage which would allow for passengers in one form and revert to racing layout in the other.
	This picture taken part way through the build shows the "passenger" version with the upright bar absent and a wider spaced back brace to allow for the passenger head and shoulders. The racing variant looks more like the other side with a straight back brace and an upright. Changeover involves undoing a few bolts, swapping tubes and replacing the bolts. The front bars from the main loop forward and then down by the a-pillars are not fitted in this picture.
	Details of the mountings which bolt into inserts in the carbon fibre tub.
	Ford GT 40 seen in the collecting area for the World Sports Car Master race at the 2009 Silverstone Classic.
	Simple main loop for forward bracing supported in the sills by spreader plates.
	The angle of the braces is limited to provide driver accessibility.
	A second McLaren F1 with the requirement for occasional passenger use.
	The conventional original cage has tubes like 1, 2 and 3 on both sides which leaves no room for a passenger. In the ARRC developed alternative tube 4 is more vertical and tube 5 is more shaped to allow for the passenger's head.
	To return the cage for full race use tube 5 is removed by unbolting from the original mounting point at the base and undoing two bolts on the main loop by the yellow ticket in the picture above. These two tubes replace tube 5 with A becoming the mirror of  tube 1 and B the mirror of 2, the top is secured with two bolts and the bases pick up on the original cage mounting points built in to the carbon fibre tub.
	This fully finished cage includes a mounting tube for passenger seat belts.
	A side view showing additional sleeving added for strength around the top of the main loop. The front tubes and screen tube follow the original cage design.
	And a third car undergoing full restoration gets the passenger carrying option.
	This is not a full roll cage but rather adding tubing to allow for seat belts mounts in the passenger spaces which were not in the original race version.
	The right hand seat is made more difficult because of all the electronics. The box arrowed fits to the left of the bigger box and almost completely covers the existing mounting points bonded into the carbon fibre tub. A complex shaped piece of steel uses those mounting points and extends to attach the outboard end of the tube.
	The left hand seat is much easier.
	And as an alternative to workshop shots here's a finished car, with adaptable cage in place, ready for action at Goodwood Festival of Speed 2011.