Escort Passport G Timer3/1/2004
Anyone who has ever modified a vehicle to increase performance has an immediate question the moment the job is done: Is it better? Post-modification performance, judged solely by eat-of-the-pants feel, unfortunately tends to be heavily influenced by optimism. If you've just bolted on several hundred dollars' worth of exhaust system, for instance, the last thing you want to hear is that the vehicle is slower than before. But in some cases it will be.
Case in point. After years of owning a bone-stock 1990 Honda CRX Si, a few years ago we finally relented and installed an equal-length header and cat-back exhaust with larger-diameter pipe and low-restriction muffler. We also fabricated a cold-air intake system, picking up high-pressure air from the front bumper area.
And the car seemed no faster than before. Acceleration was indistinguishable from stock and top speed remained a radar-verified 124 mph. Worse, gas mile dropped nearly 25 percent.
Okay, we thought, airflow has been improved to the point where as a result, either volumetric efficiency has decreased or the air/fuel ratio is out of whack and it's running lean, maybe both. After living with the condition for months on this rarely driven vehicle, occasionally doing some research on fuel injector flow rates with the thought of installing bigger injectors, we finally installed an air/fuel ratio meter. Surprise: it was running rich.
After installing an exhaust resonator upstream of the catalytic converter, enough back pressure was restored to bring air/fuel mixture back into alignment. Presto: mileage shot up 30 percent and acceleration improved.
During this whole process we'd itched to take the car to a drag strip to record before-and-after acceleration times, a sure indication of power output and an invaluable tuning aid. But it was simply too inconvenient and we contented ourselves with the trial-and-error approach. Too bad the Escort Passport G Timer hadn't yet been introduced; it'd have saved us endless hours of work.
This clever device, measuring barely 5.5 inches wide, 1.65 inches tall and an inch deep, is a two-axis accelerometer, a performance computer that can actually deliver quite a bit more data than any dragstrip. As the name suggests, it measures G forces and does so in all four quadrants: acceleration, braking and left/right. Like a 'strip, it'll record acceleration including elapsed time to 60 feet and rollout (primarily a measure of driver reaction time and staging technique, both crucial to winning drag races); time to 330 feet, 1/8 mile, 1,000 feet and quarter-mile, plus trap speed. It also displays braking distance and rate of deceleration.
If you're more concerned with handling and cornering performance, the G Timer measures lateral grip up to 2 Gs, about double what even a stock Corvette can deliver in either lateral grip or braking deceleration.
Two versions are offered. The base model GT1 ($149.95) has a 32-character, backlit LCD display and stores the last run in memory; the GT2 ($249.95) has a high-visibility blue vacuum-fluorescent display, stores 99 runs and comes with a power cord/remote control to select modes and start a run without reaching up to press a button on the windshield-mounted unit itself.
With optional software CD and connecting cable ($24.95), the GT2 will download data to a laptop, Palm or PC. We chose the GT2 due to its enhanced capabilities and higher-visibility display, the latter especially appreciated for nighttime operation. (We've found that doing, say, 25 consecutive quarter-mile runs, even on empty roads, tends to attract attention, particularly in faster vehicles. So we frequently test in the dead of night, making the bright display invaluable.)
The display can be set to eight different modes. For example, it will play back the ten best 0-60 or quarter-mile runs or all 99 stored in memory, your choice. To record handling performance data it can be set to display lateral Gs as a bar graph, numerically or as a combination of both. Curious how your driving style affects cornering grip? Now you'll have the numbers, displayed to one one-hundredth of a G.
Two options are available for either model: a direct-wire cord ($29.95) for permanent installation or for vehicles lacking a cigarette lighter power source and a VPC bracket ($9.95), a mounting bale for surface-mounting.
Operation is dead simple. For quarter-mile runs, stop the car, press the Hold/Start button until the unit calibrates itself. That done, a message appears, inviting you to start whenever you're ready. An audio tone notes the conclusion of the quarter mile run and ET and trap speed are displayed. Once stopped, by pressing the up/down buttons the complete data can be viewed at leisure: zero to 100 in 10 mph increments plus time to distance: 60, 330, 1000 and 1320 feet.
The factory-default settings are so good that although the driver can change parameters including vehicle weight, rolling resistance, drivetrain loss, aerodynamic drag CDA and others, even without adjustment, acceleration runs are generally accurate to plus or minus 0.1 second. Accurate horsepower calculation does require some input for maximum accuracy, particularly vehicle weight, and proved to be equally accurate.
We test about 80 new vehicles each year and have found the G Timer to be highly accurate. For instance, in a Nissan 350Z coupe we covered the quarter mile in 14.23 seconds at 98.4 mph, within 0.1 second and 1.5 mph of most major car magazines. Rated at 280 hp, the G Timer calculated the 3.5-liter V-6's power at 243 hp at the rear wheels, a very credible number.
Curious to see how much the 2004 Jaguar XJ8 sedan's performance benefits from its new, lightweight aluminum construction, we clicked off 0-60 in 6.87 seconds and the quarter mile in 15.13 seconds at 92.6 mph. For a smallish 4.2-liter, 300 bhp engine, this suggests that the Slim Fast approach to car construction and a new six-speed automatic clearly have benefited the plush Jag's acceleration numbers.
We've used other performance computers but the Passport G Timer raises the bar another notch in accuracy, utility and user-friendly operation. Short of owning a dragstrip or race track, for the enthusiast owner it's the best investment you'll ever make.