How we got to the point at which a 660hp, AWD turbo 90s-era Civic Si is not only a possibility, but an honest street driven reality, can be chalked up to a few different things. The first is Honda's unrivaled cross-chassis compatibility. The same compatibility that fueled an early 90s engine swap phenomenon which continues to thrive to this day, and also contributes to the notorious theft rate related to just about any popular Honda model of yesteryear. The other factor is plain old homegrown ingenuity and a knack for figuring out how to make various parts work with one another - things that Honda engineers had no reason to even consider but that the DIY crowd has relished in.
You can add Brandon Smith, owner of this 1990 Civic Si to the group of die-hards that tinker and test, wrench and repeat, until they find exactly what it is they're looking for. He's built and re-built this chassis multiple times and its current iteration is by far the most impressive. Very simple on the outside with an obsessively well-organized engine bay that plays host to a mix of custom and off-the-shelf performance parts, the sum of which look better suited for competitive drag racing than your local freeway, but make no mistake, this car is a driver.
Testing the Boosted Waters
Smith and his hatchback first joined forces back in 2007 and he wasted absolutely no time, ripping out the native single cam heart to make room for the DOHC ZC swap. Not long after came a turbo kit and around 300hp, and for the next four years, the hatch served as both daily driver and weekend warrior. That initial taste of boost was just the beginning and since that time, Brandon's gone through 10 different engine configurations, all turbo, with the exception of a single 300+hp supercharged B-series along the way. With experience and knowledge gained over the years, things got serious and his long-term Civic eventually hit the 600hp mark.
Making power has never been an issue for Honda's B-series family but on the street, big numbers have often proven to be more of a curse than a blessing, acting as an unforgiving reminder of the inherent uphill battle of straight-line, front-wheel drive performance. The idea of converting to AWD to fight this is nothing new, it was done many years ago and as such, has been talked about by many, though rarely attempted. That's changed quite a bit as today you'll find far more supporting parts from various brands offering bolt-in kits and accessories, but Smith dove in well before the mainstream took notice and as such, he's got a head full of knowledge that comes from hands-on experience. Forget about bragging rights or getting it done before the next guy, the benefit here is his ability to apply that knowledge to a real deal streetcar that stacks miles regularly and isn't a ticking time bomb.
4 Tire Fire
Smith's process of converting his Civic to AWD was a gradual one which began first with a CRV transmission, followed by a custom fuel set up in the rear that includes a fuel cell and multiple pumps, all strategically placed to make room for the necessary rear-end parts that would eventually make their way to the chassis. He adds, "the conversion consists of a bunch of custom parts, all built in-house and with the help of a couple of companies. Over time we swapped a lot of the parts that we'd used to get it up and going. Without Sone from S1 Built, it would have been possible, but much harder. I reached out to him and asked for help and with no questions, he jumped on board." To get all 4 wheels to cooperate with one another, the drivetrain is armed to the teeth and includes an OEM Civic wagon differential and viscous coupler along with Smith's own driveshaft and billet carrier bearings which he markets under his B&N Designs LLC brand. The aforementioned CRV trans is fitted with Liberty face-plated gears (1-4), Speedfactory Racing FWD2AWD gear conversion kit, Competition Clutch, and MFactory limited-slip.
Built and Boosted
The foundation for that 600hp output is a Golden Eagle sleeved and O-ringed GS-R block that houses an Eagle crank and rods, and 84mm Traum 10.5:1 pistons. Up top, a Portflow reworked head is fitted with a Supertech valvetrain and factory-issue Type R cams. The formula is in no way complex, but entirely tried and true. The excessive jam being produced comes by way of a Garret G30-900 turbo mounted to a Gonzo Motorsports manifold and overseen by a Turbosmart 60mm wastegate. Gonzo also fabricated the water-to-air intercooler kit that uses a slew of painstaking pie-cuts to snake just beyond the up-pipe and wastegate bellow, then around the swirl pot and to a Skunk2 throttle body and intake manifold. Engine demands and logging parameters are established by AEM's Infinity management which helps churn out the 660hp and a gut-wrenching 498 lbs.-ft. of torque.
The area right above the driver's engine mount is now filled with a custom catchcan that Smith also offers under his B&N banner. At the firewall, the brake booster was eliminated and in its place, you'll find a trio of Tilton reservoirs that support an aluminum CompBrake pedal box which sits just behind a custom foot plate in the cabin. Also inside, a fixed-back seat wrapped in OEM material holds smith in place while a lengthy steering wheel extension puts the Nardi wheel right in front of him while he takes cues from a Racepack IQ3 digital display.
Mild on the Outside, Wild on the Inside
Other than the hood-exit exhaust peeking through, the Civic carries a relatively mild exterior. A square set up consisting of matte black 16x8 CCW Classic wrapped in 225/45 Toyo Proxes R1R poke out from the fenders, not in the name of "stancey-boy" status, but rather using every possible method of maintaining traction. Even with AWD firepower, the lightweight hatchback is a terror and demands not only Smith's undivided attention, but his experience behind the wheel to keep a leash on it.
It's really nothing new seeing the Honda crowd figure out how to adapt cross-platform applications in order to maximize performance, that's what the community has thrived upon ever since its late 80s uprising. A build like Brandon Smith's split-personality hatch, however, which is able to cruise comfortably for hours or unleash all hell through its fortified AWD-converted drivetrain at a moment's notice, certainly is. And, this isn't over yet, Smith notes that he'll be tearing the car down for a complete paint and body makeover and will be incorporating some new parts he's designed and will market, with his sights set on SEMA to debut them.