Drift-Office Drops 300 WHP On The Hip And Heady FR-S/BRZ
The love child created by Toyota and Subaru in the FR-S/BRZ has more than lived up to the hype. It has garnered accolades for its engaging balance, smooth power delivery and gentle, under $25,000, price tag. But for many driving enthusiasts, a mere 200 horsepower is more lullaby than adrenaline squeezer…and they like to squeeze.
The aftermarket has answered the bell with a vengeance, producing a full array of go-fast parts that includes a bevy of forced induction options. While there are custom turbo kits making big numbers with built engines (Crawford Performance’s 500 hp BRZ comes to mind), 300-wheel-horsepower seems to be the magic mark for more mainstream bolt-on, stock-engine Toyobaru kits. Producing enough air to make big power is easy - but getting it to live in a high-compression engine (12.5:1) with a sophisticated fuel injection system combining high-pressure direct injection technology and conventional fuel injection is the trick.
AVO Turboworld has developed a well-engineered kit consisting of an AVO 18/49 turbocharger with 5-7 psi actuator, unequal-length stainless steel exhaust manifold, polished downpipe, a bar & plate-style front-mount intercooler with no-cut installation, black piping, mechanical oil scavenging pump, oil reservoir tank, and all necessary water and oil hoses and fittings. The kit retains factory air conditioning and AVO says 220 to 250 whp at 7 psi can be expected with the Stage 1 kit ($3,800) and its Pro ECU EcuTek base tune.
The car featured here, dubbed ‘Christine’ by its owner, Drift-Office’s Bob Wan, runs a Stage 2 kit that adds or replaces the following; larger injectors, upgraded MAP sensor, 8-psi wastegate actuator, AVO clutch, AVO lightweight flywheel, AVO 2.5-inch overpipe, AVO 2.5-inch front pipe and a AVO 2.5-inch exhaust.
Drift-Office has a stranglehold on the ‘300whp Brass Ring,’ as Christine was the first stock-engine bolt-on Toyobaru to do the deed. Bob warns that tuning the BRZ/FR-S to this level requires the use of EcuTek software, a custom calibration program that's currently pretty much the only game in town for these cars. There is also BRZ Edit, but Bob says it is still in its infancy and can only be at best described as in its "Alpha / Pre-Beta" stages.
EcuTek faced several challenges developing its tuning solutions. One of the issues was identification. There were undefined, rogue maps that needed to be addressed and compensation tables that needed to be identified.
“For example,” says Bob, “when we changed a value and set targets, the commanded value wasn't always what we saw, often due to a compensation table that hadn't been identified as of yet. Alternatively, there are feature sets that are listed that do absolutely nothing. It was nothing short of frustrating but over the course of the last 14 months, the EcuTek software has come a long way streamlining the process significantly.”
Another hurdle is consistency. “Part of the problem we see is that there's no consistency, at least to my standards,” says Bob, “in the calibration.” For example, Bob reports that of the 16 or so naturally aspirated setups that he’s tuned, no two cars, while performing well, had identical maps. Not even the few cars that were 100-percent stock matched up, some motors would take more ignition timing than others, preferred AFRs would vary as well. So the bottom line is, Bob sees no tune that he’s comfortable just downloading without putting the car on the rollers.
But he, along with Drift-Office, has the tuning phase down pretty tight - as Bob's white FR-S belts out more than 300 whp at will on the Drift Office Dynojet chassis dynamometer. Torque checks in at 255 lbs-ft at around 5,300 rpm and the curve is kind, delivering 240 lbs-ft from 4,000 rpm on up. With the Stage 2 package Drift-Office set boost to 10.7 psi.
On the positive side of the ledger, Bob is quick to point to the retention of the stock MAF in the STOCK location as a benefit. He says location is key and stresses this is true of forced induction enhanced engines as well as engines with only basic high-flow air intakes. “Pretty much any mod that moves the MAF to a different spot can be problematic,” says Bob. “Moving the sensor requires the MAF to be rescaled to get the most optimal and accurate results that are consistent.
Some MAF placements reposition the sensor in turbulent spots that no amount of tuning can overcome. Essentially, the better the MAF calibration, the better the results - the pitfall is the client will have to pay for hours of dyno time to get it scaled correctly, and even then, sometimes with dismal results.”
According to Bob, another factor in the inconsistent nature of the FA20 is its acute sensitivity to octane. “I've also seen varied results across the board; even with the same fuel! It all comes down to how "fresh" the fuel is. If it's been sitting at the pumps for a week, it's going to be less than stellar when compared to three-day old gas."
He goes on to explain, "The set-up works fine at the 92 octane level we have here in western Washington. At 91 where most of Californians are at, some tuning conventions will have to go out the window! Say we're in California where most stations provide 91 octane. Now running that in a high-compression 12.5:1 setup is just asking for problems in a NA format...but with a turbo? That's almost a recipe for disaster! The problem we see is that there's not enough "oomph" in the octane to handle the ignition timing. So tuning convention would dictate that we dial back the timing. The problem is that we don't have much room to dial it back or it'll be retarded too much and start burning up valves, but because of the limitation in the octane, it's not possible to increase timing that much either. Hence the need for a "custom calibration" and an in-depth dyno tuning session to find that proverbial ‘sweet spot’ where optimum power production is realized and knock events are not.”
Drift-Office has installed nine kits in-house so they know what it takes. Typically, a moderately experienced backyard/enthusiast mechanic with the proper tools can pull it off in 10 to 12 hours. A black charge pipe and a few AVO emblazoned hose connectors are the only ‘non-stock’ signs.
Bob’s Scion FR-S was spared no quarter when it was stuffed with gear and driven from Seattle to Las Vegas an hour after installation for the recent 86 Expo. There, in the 115-degree heat, "Christine" as Bob calls the car, was subjected to intensive back-to-back test drives, some with the AC turned up to full blast - and she didn't miss a beat!
“I haven't found the limit yet,” quips Bob, “but the turbo is rated to around 380 whp. The real question is how much boost can the stock motor hold? And to that end, I'm staying well below 14 psi for conservancy and preservation...for now!”