The cars
A motley fool ponders the entry list
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The carsA motley fool ponders the entry list |
| Repco-Brabham BT24 | BRM P83/P115 | Coventry 19R (Cooper-Masarati T81B/T86) |
Eagle-Weslake T1G | Ferrari 312 | Lotus-Ford 49 |
Murasama MA-310 (Honda RA300 'Hondola') |
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| Engine | V8 16v | H16 32v | V12 36v | V12 48v | V12 48v | V8 32v | V12 48v |
| BHP | 350 | 423 | 390 | 415 | 410 | 400 | 430 |
| Max. BHP RPM | 8,200 | 10,000 | 9,700 | 10,000 | 10,500 | 9,000 | 10,900 |
| Max. RPM | 9,140 | 11,545 | 10,400 | 10,815 | 11,262 | 9,810 | 11,825 |
| Torque (lb-ft) | 224 | 222 | 211 | 218 | 205 | 233 | 207 |
| Lbs (dry) | 1105 | 1381 | 1231 | 1165 | 1129 | 1105 | 1313 |
| BHP/ton | 709 | 686 | 710 | 798 | 813 | 811 | 734 |
| Wheelbase | 93.5 | 94.0 | 98.0 | 96.5 | 94.5 | 95.0 | 96.0 |
| Front track | 53.0 | 58.8 | 59.5 | 60.0 | 59.5 | 60.0 | 59.5 |
| Rear track | 55.5 | 60.0 | 59.5 | 60.0 | 59.8 | 60.0 | 59.5 |
| Track/wheelbase ratio | 1.72:1 | 1.58:1 | 1.64:1 | 1.61:1 | 1.58:1 | 1.58:1 | 1.61:1 |
| Rear tire diameter | 24.8 | 25.6 | 25.7 | 25.0 | 24.9 | 25.5 | 25.0 |
| Chassis ride height | 4.00" | 4.50" | 3.75" | 3.75" | 3.75" | 3.75" | 3.00" |
| AI ride height | 3.50" | 3.00" | 3.25" | 2.75" | 3.00" | 3.25" | 2.75" |
| % Weight on rear | 58 | 64 | 60 | 61 | 61 | 62 | 64 |
| AI gallons/lap Nürburgring |
2.32 | 2.88 | 2.58 | 2.62 | 2.68 | 2.50 | 2.93 |
| Performance (from GPLRank) |
60.00 | 44.45 | 44.80 | 66.35 | 65.72 | 82.34 | 44.50 |
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The official Ferrari site gives different data for the Ferrari 312, for example that it generated a maximum of 390 BHP at 10,000 RPM.
The torque was calculated with the formula BHP = torque X engine_speed / 5252. (So that's why you have to drive the Ferrari like it was a two-stroke!)
The 1967 F1 rules stated that the minimum dry weight was 500kg (1100 lbs).
The driver weighs 168 lbs (12 st).
Received wisdom has it that long slim cars (those with a larger track/wheelbase ratio) tend towards improved stability at high speeds and are less inclined to dart about. Short, wider cars are not supposed to be as fast in a straight line, are more twitchy but consequentaly are more sensitive and responsive on a tight course.
The rear tire diameters were calculated by Giovanni Tifosi using the Hewland Engineering gear calculator program. MPH = (Engine_RPM * Radius_In_Inches) / (Final_Gear_Ratio * 168).
The 'chassis' ride heights are those that keep the drive shafts parallel to the ground, as seen by a ground-level camera looking at the rear suspension of an unpatched version of each car fitted with the softest springs and dampers. The values are approximate.
...interesting to note that the level of fuel in the car did not affect the static ride height.
...and that the AI use the same ride height at each circuit.
The weight distribution figures are from a beta version of the software.
The performance ranking was taken from the fastest per-chassis time over all eleven tracks, relative to the replays that came with GPL. They show that the BRM, Cooper and Honda are evenly matched; that the Eagle is very slightly faster than the Ferrari, and that the Lotus is much faster than anything else.
GPL measures fuel in US gallons; 1 liter is 0.26417204 of US gallon (i.e. 1 US gallon is 3.785412 liters). The setup screen reckons that 1 US gallon weighs 6.25 lbs (2.84 kg) (0.75 kg/liter).
As driven by the AI, the (already lightweight) Brabham starts a full length race (Kyalami) with 128 liters (33.8 gallons) of fuel (approx 211 lbs). The (already heavy) Murasama starts with 160 liters (42.2 gallons) (approx 262 lbs).
The following gives the AI fuel loading, per lap, in liters:
Bra BRM Cov Eag Fer Lot Mur
Kya 1.60 1.95 1.73 1.80 1.79 1.76 2.00
Mex 2.11 2.56 2.30 2.37 2.36 2.33 2.56
Mco 1.45 1.68 1.57 1.60 1.58 1.50 1.68
Mza 2.24 2.73 2.47 2.56 2.64 2.42 2.75
Mos 1.61 1.98 1.75 1.82 1.81 1.75 2.04
Nur 8.88 10.90 9.80 9.94 10.06 9.47 11.09
Rou 2.64 3.24 2.90 3.02 3.01 2.90 3.21
Sil 1.97 2.42 2.10 2.23 2.19 2.14 2.37
Spa 5.22 6.45 5.65 5.89 5.91 5.62 6.42
Wat 1.51 1.87 1.68 1.72 1.75 1.67 1.89
Zan 1.75 2.15 1.90 1.98 1.99 1.93 2.13
Jack Dyson has calculated these BHP and torque curves for the Lotus:
The following torque curve graphs and descriptions were created by Chris Cavin and posted in the rec.autos.simulators newsgroup:
Lotus: Nice and fat in the middle rpm where most of your time is spent. This, with it's low weight, gives the Lotus the best acceleration of the bunch. The Lotus also retains a good amount of torque near redline, though, for good power and top speed. Makes enough torque that wheelspin is a problem if you're not gentle with the throttle.
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Eagle: Nicely linear with no abrupt increases that might cause excessive wheelspin. Good top end power and a usable mid-range, but not a whole lot of low end torque. Very drivable engine.
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Brabham: Broad and useful in the mid-range. More low end torque than even the Lotus gives great acceleration off the corners. Lower peak numbers, though, keep the acceleration from matching the Lotus and makes the Brab rely on it's small frontal area to make good top speed. Quick ramp up on the torque curve means you've got to watch out for wheelspin.
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Ferrari: Nice smooth torque curve with no nasty surprises. Doesn't have the low end of the Brabham or the Lotus, but it does have one. Mid-range is equal to the Eagle, maybe a bit better, but top end acceleration leaves a bit to be desired. Over all a nice engine.
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BRM: Very peaky motor. Virtually no low end, a very weak mid-range and high peak power make this a difficult car to keep in the power band. If not for the heavy engine, the abrupt torque increase into the power band might make wheelspin a much bigger problem. Would be a much harder car to launch off the line if not for that extra gear.
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Honda: Torque characteristics similar to the BRM, but much more usable and not as abrupt. Low end is a bit better and the mid-range is actually quite usable, though maybe not as nice as the Eagle. Smooth torque curve and the weight of the car keep wheelspin from being too much of a problem. It uses so many revs, though, that the Honda is a hard car to launch without bogging. I think it would benifit from the extra gear that the BRM has.
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Cooper: The Maserati engine is biased more towards the mid- range. It is very drivable but feels like it has a heavy flywheel. Acceleration is pretty poor compared to the other cars. The torque curve has no abruptness but falls off towards redline, which limits top speed.
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