By now, unless you’re one of the Cro-Magnon cave-dweller crowd who have somehow bypassed much of the 21st century, you’ve probably either read at least one Harry Potter book or seen one of the movies. You might even have been suitably-charmed by J.K. Rowling’s whimsical series which revolves around a magical dual world co-existing somewhat peaceably with our own. In more than a few ways, Jeff Abrams’ maniacal turbocharged 2004 RX-8 Grand Touring is a vehicle which spans both worlds. It is a solid, well-build, sensible 4-door machine with enough amenities to please any Muggle (an ordinary non-magical person). At the same time, Jeff’s inclusion of his own custom-built and tuned turbo system magically transforms the very nature of this beast into a fire-breathing, black-hearted steed, just as likely to spit you out and chew on your nether regions as it is willing to do your bidding.
Jeff’s an easy-going, intelligent guy with a serious jones for modifying Mazdas. Prior projects include a turbocharged and intercooled 2.5 liter 1993 MX-3 and a turbocharged and intercooled 1.8 liter 1997 Miata. We sense a trend here towards smaller engines and positive manifold pressure. Needless to say, since neither of those cars initially came with boost, he’s garnered a great deal of experience with turbo tuning. Tackling the doubly-difficult task of tuning for the notoriously-touchy RX-8 ECU and thirsty, dual-plug 13B-REW was probably mere child’s play for Jeff. “There were parts waiting in the garage when I got the car. I pretty much voided the warranty the first week.” Warranty? Who needs a warranty?
Since he built it from scratch, we’ll let Jeff describe the sweet turbo system details in his own words. “It’s a hand-welded, tubular manifold with a Turbonetics T3/T04E hybrid turbo with an integral waste gate and a similarly hand-welded down pipe to a Billy Boat CAT-less mid-pipe and a Mazdaspeed V2 exhaust. The cold-side plumbing is 2.5” aluminum piping, through a custom-made 30” intercooler with an HKS Super-Sequential blow off valve. The system draws its air through a modified version of the OEM air box for stealth and simplicity of filter changes. The A/F is monitored by an Innovate LC-1 Wideband O2 Controller which reports to my GReddy E-01 boost controller and data display so I can have boost and A/F information all in the same place. The Koso EGT sits on top of that and monitors temps at the inlet to the turbo. The injector staging is controlled by a GReddy E-Manage Ultimate. The Primary and Secondary injectors remain under PCM control in cruise and light throttle. The EMU takes over in boost and adds the second set of Primary injectors for total fuel flow. The EMU also controls the secondary valves in the intake and keeps the OEM PCM happy (and not reporting CELs).” Whew! Did you catch all of that? Don’t try this at home, kiddies.
For the exterior, he knew he wanted a more aggressive look to match the performance, so he ordered up the Mazdaspeed nose and side skirts, and the rear Aero flares. “I only own black cars so with the rock chips we pick up out here (Phoenix), I’m constantly repainting the nose for shows.” He’s also added the adjustable Mazdaspeed rear wing and a custom finished billet fuel door. As well, he’s also installed, on his own, a set of GT Factory Lambo door hinges. While these have become commonplace on show cars, they’re not as prevalent on daily drivers. Doors up, combined with the body kit, the look is 100 percent sinuous and sensually exotic. Not too shabby for a car available under thirty large ones!
Bringing the meat to the table is a set of 19-inch Rays two-piece G-Games Wolf 77 wheels in staggered eight- and nine-inch widths. Nitto NT-555 Extreme tires offer summer-friendly traction for this “Valley of the Sun” resident (also jokingly known as “the surface of the sun” to the natives). Brembo cross-drilled (the holes are actually cast into the rotors to avoid dreaded cracking) and slotted rotors are clamped by the stock single-piston Brembo-engineered brake calipers, and produce excellent feel and short stopping distances. Never busy, we were able to place the car anywhere we wanted in a turn, at least up to speeds which would have earned stern glances from the local law enforcement.
From behind the wheel, most of the driving motions felt like any other RX-8, with the notable exception of the Axial Flow Engineering short shifter which imparted rifle-bolt engagement and nearly 30 percent shorter throws. The spongy feel of the original shifter has been banished. Turning inputs result in the car rotating around the driver with Mazda’s impeccable balance. Stock seats, nicely wrapped with red and black leather (as is the steering wheel), offer firm support for spirited driving. The first clue, however, that there’s more hidden in the engine bay comes from firing the car up and lightly touching the gas. The HKS blow-off valve just sounds so tasty doing its job and issues forth hearty “woooosh” sounds with each up-shift.
Since Jeff is constantly adjusting his tuning, having access to the peak exhaust temperatures and boost levels with real-time control is essential. A custom car PC and full size keyboard interface seamlessly with the CD/DVD/GPS/NAV display in the center of the dash. A second, USB-driven “mini keyboard” rests over the flip-up ashtray cover. The PC is also connected via CanScan to the car itself so any warning lights can be monitored and corrected immediately. Still, life with a turbo rotary isn’t all roses. “The previous engine died a warrior’s death, pulling a grade at 12 PSI while passing a guy in a Mustang who didn’t feel he should be passed! It got a little too hot and I didn’t notice it in time to keep it from detonating. Because of the crappy gas in Phoenix, now I keep it in the 9 PSI range on hot days.” Not only is Jeff completely unafraid to get his hands dirty, he considers an occasionally blown motor to be an acceptable cost for his “fun”.
Handling receives two thumbs way up. The combination of soft (for a lowering spring) rates of the AutoEXE springs and Tokico D-Spec adjustable shocks easily absorbed the worst cracks in the parched desert pavement while providing an aggressive drop. We’ve noted that the RX-8’s suspension likes soft rates and long travel and that accentuates the mechanical grip available from the Nitto tires. Proper choice of shock rates is critical; go too stiff on an RX-8 and you’ll be chasing the tail in the twisties. Never busy, we were able to place the car anywhere we wanted in a turn, at least up to speeds which would have earned stern glances from the local law enforcement. Jeff admits that the staggered eight- and nine-inch wheels aren’t the best for pure handling but “I loved how they look on the car!”
Once the snail spins up, there’s strong power from 3500 RPM to the red-line. A turbo doesn’t change the high-revving, low-torque nature of the RENESIS to that of a V-8 but there is MUCH MORE thrust available than anyone has the right to expect from 1.3 liters. Although his last attempt to dyno the car in Phoenix wasn’t successful due to temperature issues, he reports “I was making more power at 2500 RPM than the typical RX-8 makes peak in stock trim at 8000 RPM”. First and second gears go by in a flash, third and fourth carry you into illegal territory in haste, pressing you back into the seat, fifth and sixth will get you arrested, locked up, and possibly deported. One freeway on-ramp and we were exclaiming, “This is how they should have been shipped from the factory!” Why Mazda has refused to build a boosted Mazdaspeed variant remains a mystery. Perhaps Ford wouldn’t be happy with a Mustang-whipping stable-mate, but we can only imagine what a version like this would do for the RX-8’s slacking sales numbers. Certainly the cost of a few dress-up parts, a turbo system, and tuning is lower than developing a brand-new model, right?
What was truly amazing was that, for our test drive, due to fuel quality and outdoor temperature concerns (it is a desert you know) he’d backed the boost down from his “winter” setting of 12-14 PSI down to an extremely tame 6 PSI! We asked if it’s this much fun now, what’s it like on full boil? “It can be pretty scary.” Jeff replied while chuckling fondly. While we don’t believe a turbocharged rotary will have STI or Evo owners quaking in their shoes in a drag race, it greatly improves the car’s overall tractability and fun quotient. “I turned a 290+ HP dyno run back in Maryland with a smaller turbo and less boost.” At “full power”, Jeff estimates the horsepower climbs to a peak of 320 at the tires. Weighing in around 3100 lbs, without a single piece of aftermarket carbon fiber or titanium, this brings the power-to-weight ratio under 10:1, infringing on BMW M3-like numbers, for a fraction of the cost! Power, handling, and looks? Now that’s the sort of magic we’ll take to the bank!