Tuesday 29th June was the day Zhaust.com got it’s first official look at the new chassis dynamometer set up by veteran motor sports enthusiast and businessman Ralph "Bizzy" Williams. We arranged to meet Bizzy at the facility in Gasoline Alley, to the north of the Structural Systems complex in Cane Garden, at 5pm. He arrived on time, and we quickly got into the meat of the matter - the dyno. For the official demo, Bizzy brought along his RWD Toyota Starlet, fitted with a 4A-GE power plant and a couple of wicked-looking Weber side draft carburetors. A most interesting specimen!

Bizzy and his facility manager Mark Hinkson gave us a guided tour of the equipment. Basically it's a Rototest VPA-R 2WD dynamometer (http://www.rototest.com/products/vpa/vpaoverview.html), complete with a pair of hub-mounted hydraulic pumps used to measure the output at the wheels. These pumps also power a pair of hydraulic fans capable of up to 40hp. These are used primarily to cool the hydraulic oil, but also to provide airflow over the car's radiator, so it doesn't overheat. There is also an electric-powered extractor fan to clear the exhaust gases from the room. The room is also equipped with a pit below the car, so that you or your mechanic can get beneath the car to change exhaust systems etc. There is also a vehicle hoist provided in the adjacent room for getting more up close with the car's underside, so that for example differential changes can be done on-site. The total power handling capacity of the system is around 415hp, a mark that very few 2WD machines on the island can surpass.

The hydraulic pumps measure the torque output using a pair of strain gauges mounted under the pump mechanism. These gauges can be recalibrated at any point using standard weights and a torque bar. Unfortunately, the suppliers sent the dyno system without the engine speed sensor (it’s being shipped now) so the vehicle's gear ratios must be entered into the system in order to obtain speed readouts. The system then calculates rpm's based on wheel revolutions. Bizzy also has a lambda sensor on order for accurate measurement of air-fuel ratios.

We asked Bizzy why he opted for this type of dyno instead of the more common rolling road version. His response was that this system is more accurate than the rolling road, since you don't have tyre slip losses to consider. There is no wear to tyres either, and no possibility of a powerful car breaking the tie-downs and wrecking equipment or injuring people, nor is there the chance of someone turning the steering wheel of a FWD car by accident during a run and the car jumping off the rollers. This dyno can also do steady-state measurements, allowing fuel systems to be properly mapped, whereas that is impossible on a rolling road dyno.

Then it was time to watch the Starlet run. The extractor fan was put on and the young assistant jumped in and fired it up, then let it run for a while to fully warm up the engine. Meanwhile, Mark set up the measurement PC to record the run. The system holds the rpm at several specific rpm increments (default is 500rpm increments) and makes several measurements per second at these points. All you do is start the test, then hold your foot flat to the floor. It's presently set up to measure from 3000 to 7000rpm, so immediately the revs jump to 3000rpm and hold for 6 or 7 seconds, then 3500rpm, then 4000rpm etc. up to 7000rpm. In the case of the Starlet the run was completed in two segments, allowing the car to cool off a bit in-between. The system does not care, as it measures at specific rpm points only. It also records atmospheric pressure, humidity and temperature at the same time, so that the results can be corrected to a standard temperature/pressure/humidity level. This allows for comparability of results taken days or months apart, giving you an accurate measurement of the outcome of changes made to the car between runs.

The test we did compared the exhaust which exits from the side of the car to the new straight through system which exits at the back. With the prior exhaust system in place, the car ran smoothly with no flat spots. However, when the new exhaust was put on, and the car ran on the dyno (the accurate one, not the butt dyno) it was immediately apparent that there was no discernible improvement in power up at the top end, and there was a flat spot around 4000rpm, coupled with the problem maintaining a steady 3000rpm. Possibly if the air-fuel ratio meter was available we might have seen a correlation, but remember that this is a carbureted engine, so there is no question of mapping to eliminate the flat spot.

Bizzy maintained that the dyno was basically set up to provide scientific results measurement for people - basically to provide a needed service. We did ask him the number one question being asked on the forum - why only 2WD? With the preponderance of big-power 4WD machinery in Barbados - the Lancer EVO's, Subaru WRX's, Nissan Pulsars and Mazda GT-X's - wouldn't it have made more sense to set up a 4WD dyno? He smiled in response and said that maybe some day 4WD may come, but he's happy with 2WD, and 4WD is lots more money to set up. You 4WD owners may just have to figure a way to convert to 2WD temporarily to get your testing done.

As of now the dyno is available for anyone interested in testing their vehicle. Rates are basically $200 for a steady state test (as on the Starlet above) and a sweep test (the more common type similar to what you get on a rolling road dyno), with an hourly rate after that for people who want to make changes to the car and re-test, or who want to map their ECU's properly. You can reserve time by calling Mark Hinkson at 262-3008, or the facility itself at 424-2827 (if a car is running in the dyno cell forget about getting through on that last number, though!)

We'd like to thank Bizzy for giving us a personal tour of the facility. We are impressed with it so far, and look forward to future developments. In the works is a performance parts department, not focusing on any particular make or brand, but basically what the market calls for. It's all good in Cane Garden!