Brian Yeung likes being first. He started fiddling around with friends' cars before he could drive. He stuck Supra taillights onto something that wasn't a Supra before that sort of silliness was out of bounds. And he ordered himself up an FR-S as soon as he got word that Scion would be selling the rear-wheel-drive coupe. But living in Florida meant that being first wasn't always easy. "The car scene was always behind," Brian says about those early days, usually finding out 12 months later than the West Coast that things like racing stripes and monster-tach shift lights were no longer cool. "So when I would get a chance to visit family in L.A., I would also search for car parts for myself and my friends." And, by default, brush up on what he'd otherwise have to wait another year or two to find out.
Brian's since relocated to the other side of the country and, nowadays, plays a part in directing the movement he once traveled 2,500 miles back and forth to take cues from. And by directing the movement, we're talking about that FR-S of his being the first of its kind in the U.S. to wear Varis' Kamikaze aero. And if for some reason hand-laid fenders, diffusers, and an assortment of carbon panels don't get you all riled up, know that this FR-S' boxer engine is also the first to puff through both GReddy's turbo system and the company's bolt-on quartet of individual throttle bodies.
Ask Brian and he'll tell you he never planned on doing anything out of the ordinary with the Scion, a car that succeeds multiple cars of his that've made their way into magazines and even to the halls of SEMA. He'll even tell you that, at first, the FR-S was only half his. "[It] started off as a project between my youngest brother and [me]. I intended to have just simple body mods with wheels and good suspension set up to be a daily, fun car," he says. "As the years passed, we started to modify it more and more, the styling of the car began to evolve, and my brother decided he no longer wanted to be involved in this project, so I took [it] over and he got a Prius out of it." Brian: 1, brother: 0.
Brian—sales manager for Mackin Industries, the North American distributor of brands like RAYS Wheels and Project Mu—tapped into his network of industry peeps to arrange things like that whole multi-layered arrangement of throttle bodies stashed in between his FA20 and that GTX2871R turbo. GReddy's technicians fastened all of the bits into place, making sure both methods of induction got out of each others' way. They even went on to fabricate a one-off exhaust system just for Brian's FR-S before wrapping the whole thing up.
Like so many of Brian's previous projects, this FR-S was also SEMA-bound. And as is often the case with anything SEMA-bound, timing was critical. And by critical, we mean there wasn't enough of it. "Receiving the kit a few weeks prior to SEMA was very nerve-racking," he says about the Varis bits, "and having Evasive and Auto Tuned put the car together right before SEMA was stressful."
But nobody's feeling sorry for Brian. He has two-way-adjustable Moton shocks, Project Mu brakes, and TE37s all around to make him feel better. He also has more than 310 whp—not bad for a guy who's relatively new to boxer engines. "Other than a few of my friends' STIs," Brian says, "I'm more familiar with Nissans," which is evident by the list of S13s, S14s, 350Zs, and G37s the guy's gone through, one of which made his cross-country move possible. "I was able to source the first Esprit kit on the East Coast," he says about the Z that made it to SEMA some 14 years ago by way of RAYS Wheels. "[That] car was my link to moving from Florida back to California to work for Mackin."
For Brian, the FR-S was meant to be what he describes as a fun daily driver, but the car's extensive list of updates renders it just as much impractical as it is fun. It's a trend Brian's fallen prey to more than once, most recently manifested in the form of an Evo X that was meant to facilitate his growing family but ended with a widebody kit of its own and, like the rest of his cars, impracticably undriveable. "[It] started off with just simple mods as my daily driver," he says. "Somehow that didn't last." It almost never does.
GReddy ITB Kit Review
GReddy's gone ahead and made fitting an FA20 with individual throttle bodies so easy, even you could do it. It starts with a couple of pairs of remanufactured throttle bodies nabbed from Toyota's 20-valve 4A-GE engine of the '90s and is controlled by way of the electronic throttle body you've already got. GReddy's specially made, cast-aluminum adapters make bolting everything onto those heads a cinch and the included cast-aluminum plenum means hooking it all up to, say, a turbo or that factory intake of yours, won't be hard. Like most power-adders, the kit isn't CARB-legal, and you'll need some sort of aftermarket tuning solution to make it work, but you'll rest easy knowing every single clamp, hose, and silicone coupler is included, making for an easy installation.
Installing GReddy's individual throttle bodies starts with you yanking off everything you won't need, like the intake manifold, as well as everything that's in the way, like the ECU, fuel rails, injectors, and throttle body.
The whole kit is based on Toyota's 48mm throttle bodies that came standard-issue on its 20-valve 4A-GE engines from two and a half decades back. GReddy has them reconditioned and pre-mounts them onto a pair of specially designed, cast-aluminum adapters that bolt directly onto the FA20's cylinder heads and work with the engine's original fuel rails and injectors.
It's GReddy's unique system of linkages and brackets that adapt its mechanically driven throttle bodies to the FA20's electronically controlled throttle. You'll need to remove the throttle body's butterfly valve before fastening the new bracket into place.
Although you'll need to install each of the kit's components separately, the whole system is fairly self-contained. The cast-aluminum plenum and its four adapter pipes can be tossed aside on naturally aspirated applications where velocity stacks might be used or it can be retained for connecting to the factory intake system, most aftermarket intakes, or even a turbo's charge piping.
Not having a conventional intake manifold means there's no longer a vacuum source for things like that brake booster, for instance. GReddy supplies its own vacuum canister that connects to everything the FA20's manifold did, including the original MAP sensor.
Anytime individual throttle bodies have been integrated, they've got to be adjusted so that they all yield the same amount of vacuum. GReddy includes the meter you'll need to adjust all of this as well as a MAF sensor emulator. The emulator plugs into the factory engine harness, fooling the ECU into thinking the MAF sensor's doing its job, when in reality it's been temporarily set aside along with the intake piping it's attached to.
How Turbos and ITBs Coexist
All this time you've been thinking individual throttle bodies and natural aspiration ought to remain exclusive to one another and you've pretty much been wrong. It turns out that multiple throttle bodies and forced induction get along just fine, too, thank you. Ask the turbo and it'll tell you all it wants to do is compress a whole bunch of air—it doesn't care where it goes after that. Unlike naturally aspirated layouts where that pile of throttle bodies can individually suck up the oxygen right in front of them, having a turbo in their way means some sort of manifold's got to be there to tie it all together. The manifold doesn't just send air from the turbo's compressor outlet to the throttle bodies, it does so in an evenly distributed sort of way and with the sort of crisp and immediate throttle response you've come to expect from a multiple-throttle body layout. But there are drawbacks. Tuning can be more of a challenge, for instance, since both manifold pressure and throttle position now have to be considered when configuring engine management fuel tables. Get it right, though, and you could end up with the best of both worlds.
Your first inclination when installing individual throttle bodies is to expose them in all their glory, bolting on a set of velocity stacks, and sharing it on the 'gram. If there's a turbo someplace under the hood, though, you won't be doing any of that, which means bolting on GReddy's provided intake plenum just became pretty important. That is, if you want that compressed air that turbo just whipped up for you to make its way into those cylinders.
Know that peak power doesn't necessarily make you any faster and you'll see the good in this dyno sheet. Bolting on GReddy's individual throttle body kit onto Brian's already turbocharged FR-S led to mid-range gains as high as 30 whp and 36 lb-ft of torque.
The ITB/Drive-by-Wire Solution
Incorporating more than one throttle body into something like the FA20's drive-by-wire electronics goes beyond you arranging the right assortment of linkages and cables. You still have to do all of that, but you also have to keep that original drive-by-wire throttle body around. Here, there won't be any air passing through it and you can position it just about any place you want; instead, the throttle body's electronic actuator has to mechanically link up to the new throttle bodies. In other words, you can't get rid of the actuator since it's what's being controlled by the pedal and your right foot.
GReddy's specialized throttle bracket bolts to the FA20 throttle body's butterfly shaft, only without the butterfly valve. Once plugged in to the engine wiring harness, the throttle body's actuator will continue to rotate its shaft when your foot tells it to, only now it'll be rotating the bracket and directing a series of linkages instead of allowing any air to pass through it.
All we care about at this point is the original throttle body's electronic actuator, which, when you step on or release the gas pedal, will pull and push the linkages, opening and closing each pair of the throttle bodies you've just installed.
His and Hers
Brian isn't the only one who moved out from Florida to Los Angeles. Wife, Julia, also did, and she's the owner of this Vertex-kitted S14. The S14 was her car in college, which was built to its full potential years later. Eventually, it graced the cover of our Nissan Issue two years ago. So, who did it better?