I took part in the IMOC-Houston “Dyno Day” held at Flat Rate Performance on August 26, 2000. There were about 20 MR2s in attendance, mostly mk2s, but with a few mk1s and a mk3 too. When the MR2s were finished a Mustang Cobra R and a (genuine) Shelby Cobra were strapped onto the dyno for a run.
The engine of my MR2 Turbo was completely stock at the time of the run and performed exactly as I had hoped, producing a peak of 178.5 ft-lbs of torque and 172.0 hp at the wheels. This corresponds just about perfectly with the 200 ft-lbs/200 hp rating from the factory. The torque peak (if that little blip can be called a ‘peak’) occurs at about 4200 rpm while peak power comes in at 5700 rpm. The torque curve is pretty much flat from 3200 rpm to about 5500 rpm after which point the small stock turbo starts to run out of breath.
The chart really shows why holding a gear all the way to redline isn't the way to the best performance with this car. Because the torque really starts to fall off after 5500 rpm by the time 6500 rpm has been reached you'll get just as much power in the next highest gear, which will generally take the engine speed down to 5000 rpm or so. So I think 6500 rpm is the time to shift gear in this car if the fastest acceleration is required. Of course, making modifications to the car changes the shape of the torque (and hence power) curve, so this analysis is only valid for this particular car, although it is likely true for all stock MR2 Turbos.
The dyno chart is available here:
I also entered the figures from the dyno printout into an Excel spreadsheet, which if you're really interested, you can download here. Note that I only entered the figures for the torque reading, since the power figure can be derived from the torque by the simple equation:
Power = Torque * RPM / 5252
This equation only works for power in hp and torque in ft-lbs. For other units you'd need a different constant value. The relationship between these two units explains why dyno plots using them always show the torque curve crossing the power curve at 5252 RPM.
Some images of my MR2 on the dyno are shown below. These were taken just after the run - while the car is being dynoed it is securely strapped to the machine to avoid an expensive accident should it come loose at 6000 rpm in 4th gear.
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