Home UCD Racing - R4
Engine
As with all of its predecessors, UCD-R4 uses a Honda CBR600 engine, still the engine of choice among many Formula Student teams worldwide. Many variations of engine air intake and exhaust manifold geometries were simulated using both the Virtual 4 Stroke one-dimensional engine simulation package, and also the CFX 5.6 Computational Fluid Dynamics package. Results were then verified with experimental testing of the engine on the dynamometer.
Extensive work was also carried out on the refinement of the fuelling and spark timing maps of the engine. Using the DTA engine management system, the cell-to-cell transitions of key areas of the map were smoothed, resulting in improved driveability, while maintaining overall performance levels. A number of distinct maps were developed, each tailored to the characteristics of specific dynamic events. In the endurance event, for instance, fuel efficiency is a factor, and it has been found that significant fuel efficiency gains can be had for relatively small BMEP penalty. For other events the engine is tuned for maximum BMEP, regardless of fuel efficiency.
Drivetrain
The drive train came in for some more significant redesign. A decision was made to switch from a Torsen LSD to a Quaife unit to reduce the cost, weight, and manufacturing time of the drive train. Overall, the UCD R-4 differential assembly is 30% lighter than that of R-3. The solid GKN drive shafts that had been employed previously were replaced with lighter hollow units, designed using I-DEAS 9, and a significant effort was directed at reducing rolling resistance.
Chassis
The 2004 (mild steel) spaceframe is similar in concept to the 2003 design, which had drawn praise from the judges for its removable rear section, good load paths, and high degree of driver protection. The relationship between driver, wheel and pedals was modified slightly in the light of feedback obtained from post-competition testing, the footwell was reduced in size and lightened, and the sidepod supports were refined. The very strong and stiff cockpit concept (incorporating a third horizontal rail near the driver's shoulder level) was retained, and the driver's head was again positioned within the main roll hoop. As before, all design and analysis was carried out using the I-DEAS 9 3-D CAE package, which predicts a 6% improvement in stiffness:weight ratio over last year's design.
Suspension
UCD-R4 uses non-parallel, unequal-length wishbones front and rear, with coil springs and Fox dampers actuated by pull rods at the front and by push rods at the rear. Kinematic analysis was performed using SusProg3D, and the linkages were arranged to produce 0 degree k.p.i., zero camber change in bump, zero bump steer, and a very stable roll centre. Work continued in 2004 on the switch to carbon-composite tubing for the A-arms and front pull-rods, to reduce unsprung weight and of course overall vehicle weight. This involved significant and fruitful interaction with technical staff of Henkel-Loctite (Ireland), who are supplying the adhesives nec
essary to bond the composite tubing to the steel rod-ends and bearing housings. The successful integration of these composite suspension components amounts to a 42%, or 3.3kg, weight saving over the corresponding 4130 steel components. The front upright design was refined and now incorporates camber adjustment (-4 degrees to 0 degrees ), improved toe stiffness, and permits increased steering lock, while a “break-in” rig allowed the rod end friction to be reduced prior to first running in the car.