Power Pages: Toyota MR2 Spyder

With the disappearance of the mid-engine, rear-drive, two-seater platform in 1996, a gaping hole was left in Toyota's compact sports car lineup. Sure, the Celica remained (in various guises), but the public wanted something a little bit sportier. In 2001, Toyota unveiled the MR2 Spyder, a sport convertible based loosely on the MR2 original platform--mid-engine, rear-drive, but this time with a ragtop for hours of hair tussling madness. Some MR2 purists bemoaned the loss of the optional turbocharged motor, but soon grew to love the new roadster and its super-high performance motor.

The Engine
The 2001 MR Spyder is powered by Toyota's 1ZZFE motor, akin to the engine found on Toyota's sport coupe, the Celica GT. Factory power ratings show this powered rollerskate peaking at 138 hp at 6400 rpm. Peak torque clocks in at 125 lb-ft at 4400rpm, not exactly neck-snapping but surely nothing to sneeze at. Using Toyota's variable valve timing technology (VVT-i), the Spyder has the goods to deliver off-the-line torque as well as high-rpm power, while still maintaining a pleasant demeanor when not under the gun.

Performance Components
The first step in upgrading our two-seat rollerskate was replacing the factory intake system. As with most OEM intake systems, sound dampers and resonator boxes have been added by the manufacturer to reduce engine noise and to increase driver comfort. However, some of us are more comfortable with a screaming engine and the extra power that comes with releasing the intake from the suffocating clutches of these dampers. This is where the Injen Intake comes into play. Injen constructs its system from mandrel-bent 6061 aluminum because of its light weight and strength. Aluminum also has excellent heat dissipating properties and a strong resistance to corrosion. The piping size used in the kit was determined after examining a number of factors--size restrictions, relative filter placement, and maximum usable airflow capabilities, as is the case with all Injen intakes.

Part two of our MRS upgrade came from TRD in the form of its exhaust system. Despite its physical appearance, the exhaust is a true cat-back system that replaces the undersized factory piping with stainless-steel tubing; the diminutive size is dictated by the presence of the motor in the middle of the car. The TRD exhaust piping is also mandrel-bent to eliminate disruptions in exhaust flow, and since it's constructed from stainless steel, its finish also inhibits corrosion. The muffler canister is also made from the same high-grade stainless steel material. You can rest assured that TRD engineers did their homework and created the best possible system that combines the highest flow characteristics with solid integrity and an exhaust note worthy of a two-seat sport convertible.

Our third power adder was APEXi's ever-popular Super AFC Digital. This little piece of electronics allows for precise and consistent fuel tuning of EFI cars by piggybacking the factory ECU and modifying the air intake signal at predesignated rpm points. The S-AFC Digital works on a multitude of cars that use several popular types of air intake sensors, making it a true universal bolt-on power adder. The display can be mounted and configured to show real-time data when not in program mode, including a mode that simulates a screen of analog dial gauges. The latest in microprocessing technology is used to ensure that the S-AFC Digital keeps up with the speed of the car's ECU. It is one of the most handy, cost-effective tuning tools on the market today.

Dyno Testing
We strapped the car on the Dynamic Autosports' Dynojet and made a few pulls for the baseline numbers. Horsepower checked in at 125.7, while torque came in at 113.9 lb-ft. We expected the horsepower to be a little less after figuring in the drivetrain transfer loss; the factory rated 138 hp should have checked in at about 115-117 hp. Apparently, our test car has a motor built by happy assembly-line workers.

Installation of the Injen intake was straightforward, as the instructions were clear and the mid-chassis-mounted engine was easy to access. After tightening all the nuts, bolts, and clamps, we made another pull on the dyno. Maximum power peaked at 128.7 hp in the 6000-6500 rpm range--this is excellent news considering the car's 7000-rpm redline. There was very little drop off in the upper regions, and this means that the car pulls evenly from the time you mash the pedal to the time you shift gears. Examining the graph shows that additional power begins to be realized around the 3000-rpm mark and continue to grow until power peaks around 5200. From there, the usable power increase stabilizes and continues until redline. Torque also increased to 116.5 lb-ft adding more off-the-line performance.

The TRD exhaust was a little bit trickier as several undercarriage elements hindered the installation process. First, the engine has quite a few plastic undercarriage protectors that need to be removed to access the exhaust system. Second, the available space for movement is hindered by the chassis configuration and the placement of the factory rear sway bar. Powered by his Radiohead CD collection, Aries "Dynamic" Dizon installed the TRD exhaust as quickly as time would allow and got the car back on the dyno. In the end, the exhaust netted an additional 3.3 hp and 2.9 lb-ft of torque. The graph showed power gains from the beginning sample at 2000rpm all the way to redline, again stabilizing at 5200 rpm and continuing to redline. Apparently, this is where the motor reaches its maximum operating efficiency and then continues this trend until it reaches maximum power output around 6300 rpm. Like the addition of the intake, power drop off was very minimal from this point until redline.

The A'PEXi AFC wundertool was, thankfully, easy to install. However, it was already late in the day and time was of the essence. Therefore, tuning of the AFC was limited to only one run based on Aries' prior tuning experience with Toyota's variably timed engines. This single pull tuning netted 1.3 peak hp, but caused a slight fallout in torque, which checked out at 116.8 lb-ft. The peak horsepower was gained in the upper region of the rpm band starting at 4600 rpm and continuing to redline. Torque numbers followed a similar trend, but it is noteworthy to say that the drop in torque was not evenly distributed throughout the torque graph but rather centered around a peak/valley combination that was evident when overlaying the graphs. The rest of the torque curve ostensibly stayed the same.

Conclusion
The demise of the MR2 platform did not necessarily spell doom for those seeking ultra-performance from a small Toyota package. The MR Spyder seems to be a motivated go-getter, designed as a convertible from the ground up, that needs a little bit of inspiration to live up to the legacy of its older brother.