Project Mazdaspeed Protege found its way back into Turbo's Dyno Cell. The intake system was at issue; more specifically, kicking the stock box to the curbfor an aftermarket open-element setup. Since we opted for a front-mount intercooler, our choices were limited. Luckily, iON Performance makes a cold-air intake that works with the FMIC.
The prototype kit came without directions, but there weren't as many pieces as the FMIC kit; hence, no free-hand sketches this time. Also, the smallest connector hose was too small to fit on the turbo outlet. We had to cut the stock window washer reservoir bracket and bolt it to a provided bracket that repositioned the reservoir, then grind the buttress on the U-pipe bracket.
The piping fits nicely under the hood and the kit uses a pre-existing hole in the chassis for excesses to exit the engine bay. The filter element mounts in a compartmental space just in front of the car's inner fender. A section of the grillework on the MSP's nose leads directly to the element, which means there should be plenty of fresh air at the ready, especially at speed.
With the iON Performance intake secured, the MSP was positioned on the dyno. After the typical high-reading first run, the Protege settled into its normal, repeatable pattern. The 2.0-liter, T25-boosted four-cylinder pumped out 164.5, 165.1, 165.0 and 166.2 runs in fairly quick succession. All the runs were made at stock boost levels (there is no controller installed) and we observed a boost gauge during the runs and saw the same behavior as we did during the FMIC testing.
The turbo would boost to .5 Bar and settle to .4 Bar at the end of the pull. Peak power improvements were in the 5- to 6-hp range, but the intake really earned its keep low in the powerband. From 3500 rpm to 5000 rpm, there's a uniform gain of around 17 whp, with the biggest jump hitting at about 4700, where 24 whp was realized. This emphasizes the restrictive nature of the OE box. We were also happy to see an improvement in the air/fuel ratio; the curve didn't dip off the chart as in earlier tests. On the torque side peak numbers jumped from about 160 lbs-ft to 172 lbs-ft.
On the road, the MSP has been stirred to life. The sound of the air being sucked into the engine conjures up visions of a black hole annihilating planets. The rush of air and a more aggressive sounding blow-off valve are joined by more low-end thrust.The Mazda is even more fun to drive on many levels and the car's balanced handling is still a surprise after all this time.
The engine feels more responsive, but in some situations it doesn't seem to pull as smoothly as it should. This is most likely due to the rich OE programming at the top end; it's this part of the power curve we hope to address with a factory flash tuning of the ECU. Stay tuned.