The factory twin turbo system...
The factory twin turbo system has been replaced by a GReddy T78 turbo kit. Boost is set at 17 psi and monitored by GReddy's PRofec-B control module.
That said, there are no aftermarket kit pieces attached to the gracile factory body panels. Hell, the rear end doesn't even sport a subtle factory wing. The only real modifications that were carried out were the addition of Japan-spec round taillights from a 1997 third gen and a set of H4 headlamp bulbs to increase nighttime visibility. The only exterior clues to the car's performance potential might be the slight ride height drop (about 0.75 inches) effected by the Suspension Specialties springs and adjustable Tokico dampers. The altered running gear might also catch your attention, 17-inch Forgeline RS wheels wrapped in some serious Yokohama AVS Sport meats, sized 225/45-17 up front and 285/40-17 in back.
Other suspension mods have been kept fairly basic. The system still incorporates factory-issue lower stabilizers and a factory rear upper strut tower brace. The only addition is a Suspension Specialties upper strut tower brace that was bolted onto the shock towers in the engine bay. Even the brakes remain unaltered, aside from a set of Bonez Stage One performance pads to clamp the factory rotors and Rotary Performance stainless braided lines to relay pressure from the factory master cylinder. While the stock binders have so far been up to the task of keeping a tight reign on this street-legal monster, Ott acknowledges that pushing the car to its absolute limit would probably warrant installation of a big-brake package.
The dyno chart reveals that...
The dyno chart reveals that Rotary Performance cracked the whip to the tune of 411.9 hp, a 200-hp leap in output.
Now let's take a look at what makes this car truly impressive as an ultimate street performer. Work on the 13B-REW rotary powerplant was carried out in two stages. The first was making the power, and the second was tending to emissions issues. To begin with, the factory twin turbo configuration was dismantled and replaced with a single-turbo induction system. This new system is centered around a GReddy T78 turbo kit, which includes a T78 turbocharger, stainless steel exhaust manifold and GReddy Type R wastegate. Boost is controlled by a GReddy PRofec-B, with a maximum of 28 psi possible. Normal running boost is set at a more modest 17psi, the setting at which Rotary Performance's 400 hp dyno run was made.
To keep operating temperatures down and efficiency up, the intercooler system was also upgraded. Rotary Performance tested two different setups here, using both traditional and front-mount configurations. While the standard mount was effective, the testers found it was more prone to heat soak and, consequently, gradual power loss after repeated runs on the dyno, For this reason, Rotary Performance went with the front-mount system. Even without a special bumper to allow unrestricted airflow into the core, Ott tells us there are no flow or cooling problems with this system. Mounted directly behind the intercooler core you'll also find an aluminum Fluidyne radiator, installed to remedy the RX7's well-known overheating problems.