Howston G4 & G6

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The Howston HG4 and HG6 are based off the designs of the Lola T70, a successful racing car from the 1960s. In 1965 and 1966, the T70 was the fastest race car in the world, and at that point could outpace a Formula One car. It boasted stable, predictable, handling along with blinding acceleration.

With a pedigree from the Ford GT40, the Lola T70 was tested and developed by World Champion John Surtees. Though designed for endurance racing, it had much success in sprint races, due to superior handling. It is generally considered to be the car which advanced an understanding in racing that increased drag could be an acceptable penalty for increased downforce.

The T70 went through many configurations until eventually changes in sporting regulations made the car obsolete.

Shifting these historic cars is perilous. On the longer circuits the engines spend a lot of time near the redline, and while this is optimum, it will lead to mechanical failures in longer races. Power doesn’t drop off too much after the peak power RPM in any configuration, and given most configurations carry a 4-speed, you should shift at the redline, but should probably reduce revs for endurance races – although shifting before the peak can bog the car down! For races under 3 hours, which could be taken at maximum RPM, the optimal shift point from third to fourth could be done around the 7300 RPM mark assuming the ratios are close enough.

The G4 MkIIIB has an extra gear, but you should redline this car too, because the peak power is also at a slightly higher RPM.

These cars used a H-pattern shifter and a manual, hydraulically activated pedal system, twin plate 7.25 inches.

G4 Mk III G4 Mk III 68 G4 Mk IIIB G6 Mk I G6 Mk II G6 Mk III G6 Mk IIIB
Torque 655 Nm 510 Nm 540 Nm 515 Nm 630 Nm 655 Nm 690 Nm
Revs 4800 RPM 5000 RPM 5000 RPM 4600 RPM 4600 RPM 4800 RPM 4800 RPM
Power 550 hp 425 hp 450 hp 400 hp 490 hp 550 hp 590 hp
Revs 6700 RPM 7000 RPM 7000 RPM 6800 RPM 6800 RPM 6700 RPM 6700 RPM

The Howston G6 was built at a time when tire developments were rapid, increasing width significantly with every evolution of the car. Tires in this generation were hard wearing and could usually last over 3 hours. Specific wet tire compounds and patterns were a late addition. Optimum temperatures around 80-100°C. Bias-ply tires like those used on the Howston need a slightly looser driving style than most modern radials, essentially the peak grip is where the back of the car takes a slightly larger radius than the front.

Wheelbase is 2.415, and the same for all configurations. Track widths are approximately the same for all configurations except the G4 Mk IIIB, which has a narrower track to accommodate the wider tires.

Steering wheel rotation for the car is set to 1.75 turns (630 degrees).

Front Tyres G4 Mk III G4 Mk III 68 G4 Mk IIIB G6 Mk I G6 Mk II G6 Mk III G6 Mk IIIB
Width 234mm 254mm 264mm 213mm 213mm 234mm 254mm
Diameter 650mm 647mm 639mm 648mm 648mm 650mm 647mm
Rear Tyres G4 Mk III G4 Mk III 68 G4 Mk IIIB G6 Mk I G6 Mk II G6 Mk III G6 Mk IIIB
Width 287mm 287mm 368mm 257mm 257mm 287mm 308mm
Diameter 681mm 681mm 687mm 681mm 681mm 681mm 682mm

Braking was perhaps the poorest comparative statistic of these 1960’s machines compared to today’s race cars. 1960’s ventilated steel discs worked with asbestos brake pads, an optimum temperature around 450°C, though providing good fade resistance until around 750°C. Front/Rear caliper piston ratio’s provide about 56% front stopping bias with a 50% balance bar setting.

The HG4 and HG6 have many different configurations. They alter the handling, downforce, power and speed of the cars by quite a large amount. The HG6 changes are quite visible, and you can see different wing and rollbar combinations when you select which model to run.

We have used our physics tool to calculate the figures in the table below (larger numbers mean the car is better, but it can also mean increased difficulty in some cases):

G4 Mk III G4 Mk III 68 G4 Mk IIIB G6 Mk I G6 Mk II G6 Mk III G6 Mk IIIB
Top km/h 335 303 313 296 315 320 316
Accel G 0.83 0.73 0.82 0.8 0.81 0.84 0.87
Braking G 1.45 1.42 1.48 1.36 1.4 1.45 1.52
Cornering G 1.15 1.16 1.18 1.12 1.13 1.15 1.2

The Howston HG4 and HG6 are free addons for our racing simulation rFactor2. Download the cars here.


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