A Tale of Two BRZ Tuners


Version 12.1

Most people buy a new car and are fine with keeping it stock. Others, however, view a car as a blank canvas, ready to be turned into whatever they can imagine. 

Meet the passionate hobbyist and the seasoned pro. They both love their Subaru BRZ vehicles and love to tune them, taking their cars one step beyond stock ... and then another. The limit? Budget and their imaginations.

The Hobbyist: A Tinkerer at Heart 

I saved every hourly paycheck until I could afford it.

Consider Isaac Katz. He’s a former intern at Subaru of America, Inc. now working for a digital agency in

Philadelphia, Pennsylvania. As he explains it, he’s always tinkered with his cars. “I grew up in a car culture,” Katz says, “so I’ve done a little work on most of the cars I’ve owned – just cold-air intakes and some minor exterior modifications.” 

The Hobbyist Issac Katz - Photo: Mike Spock

The Pro: Born to Tune

My dad raced when I was a child, so tuning cars is in my blood.

Taking Subaru passion way beyond reasonable limits is Quirt Crawford, owner of Crawford Performance in Oceanside, California. “My dad raced when I was a child, so tuning cars is in my blood,” Crawford explains.

The Hobbyist: Love at First Bite 

Katz got bitten by the Subaru bug when he was given a chance to drive a new BRZ while working at Subaru of America. “I took some on-ramps pretty fast. That was it! I told myself I had to have one. I saved every hourly paycheck until I could
afford it.”

Photos: (left) Steven Happel, (right) Vincent Knakal/Mad Media

The Pro: Hooked on the Potential 

Crawford got hooked on Subaru when he was asked to sort out a Subaru-engined sand rail – think of it as a long-wheelbase, purpose-built dune buggy. “I got a call from a buddy who said he couldn’t get the Subaru engine running right. I said I’d tune it for him,” Crawford says. “Once I worked on it, I was amazed at the potential.”

It made crazy power with a turbo and it was easy to tune.

That experience and his growing expertise with Subaru engines developed into a healthy business. “I sold more than 300 complete, turnkey packages for that engine – all the wiring, turbocharger, fuel lines, everything.” In more recent years, Crawford is renowned among Subaru enthusiasts for building Ken Block’s “Gymkhana” cars. The BRZ, however, was a new challenge.

The Hobbyist: Real-World Challenges 

Back in the real world of paying the rent and working a day job, Katz explains how he finds the time and space to modify his daily-driver BRZ. “Some of the work I do in parking lots, but I usually take the car to my parents’ garage. You may hear some loud noises coming out of the garage if something’s not going well,” he laughs. As passionate as he is about performance, you get the impression that Katz doesn’t take himself too seriously.

Right: Katz installs a hose clamp on his PERRIN inlet tube. Photos: Mike Spock

“The MSRP of this car was so affordable,” he explains, “that I was able to order a Borla® Cat-Back™ exhaust and headers when I first bought the car ... actually, I may have ordered them before I got the car.” These modifications enhance engine “breathing,” helping to increase power.

I'd love to supercharge it, maybe take it up to 280 or 300 horsepower.

“My mods are pretty tame right now,” Katz says. “It really doesn’t need suspension mods, because it handles well, and it doesn’t jar your teeth loose on rough pavement.” He pauses for a split second before adding, “I do have some Japanese STI rims for it that are being wrapped with sticky autocross rubber.” 

One thing always leads to another with tuning, but life’s other priorities sometimes take precedence. “I’ve got some budget restrictions right now because I have a wedding coming up,” Katz explains. And how does his fiancee feel about his tuned BRZ? “She drives it, too. She even rev-matches on downshifts.”

So is his BRZ complete, or more to the point, will it ever be?

The Pro: Double Your Fun 

Switch gears now and consider Crawford’s amazing project BRZ. How does 450+ horsepower and 550 lb-ft of torque sound? “The BRZ looks great and is beautifully balanced, so it was a natural choice. And I wanted mine to have enough power to scare me,” he explains. “I think I’ve succeeded.”

Crawford installs the cylinder head on an engine block. Photo: Vincent Knakal/Mad Media

Using all the “tricks” he’s applied to many Subaru engines, Crawford installed an STI twin-scroll turbo, maxed out the boost, and fabricated the parts to make it all work. “What I did not realize,” he says, “was how much power and torque it would make.”

Even with such a healthy jump in power, the highly praised handling of the BRZ keeps the car planted. “What surprised me was how well this car recovers from an out-of-control situation, like sideways at 70 mph or overshooting the braking point going into a corner on the racetrack.”

Back in the day, hot-rodding meant putting on a bigger carburetor and exhaust headers, or if you really had some money, a supercharger. Today, electronics control everything from fuel and spark to traction and Vehicle Dynamics Control. “Programming the BRZ computer took a long time to get right,” he explains.

Remapping an Engine Control Unit (ECU) definitely is time-consuming and involves trial and error. “I’ve reflashed the ECU in my BRZ about 1,000 times – that’s not an exaggeration,” Crawford notes. “I had to start with a system that thought it was naturally aspirated and put in parameters for a turbocharger. I also reflashed the traction control system so the car wouldn’t go sideways when you put your foot into it.”

As it sits today, Crawford’s BRZ is complete. But there’s always another Subaru project waiting around the bend. Next up is a turbocharged XV Crosstrek. 

The Hobbyist: A Spot in His Heart 

Back to Katz, the soon-to-be-married tuner with a more realistic budget. What’s next for him? While he admits to daydreaming about other mega-horsepower cars, “I don’t know if the BRZ will ever leave,” he says.

“My fiancee has an Impreza, and this is my second Subaru,” he says, “so I guess Subaru will always have a spot in my heart.”

Something for Everyone 

For thousands of owners of Legacy GT, WRX, and WRX STI models, and now BRZ sports cars, leaving it stock is simply not an option. Whether mild or wild, tuning a hot Subaru to make it hotter is a natural.

Talking the Talk

The modern tuner can’t rely on the typical hot-rodding methods of even a couple of decades ago. “The traditional performance mods from the past are of little benefit to the new motors, since most of them come from the factory with better components for making power, like hot camshafts and free-flowing cylinder-head ports,” explains Quirt Crawford. 

What’s left for the tuner? Plenty! Pushing more air into the engine with a supercharger or turbocharger offers the biggest boost in performance. Fitting a low-restriction intake and exhaust system also helps. Other than that, reprogramming the ECU via “reflashing” commonly is used to increase power. 

Just as tuner methods have changed, so has their vocabulary. When a couple of tuners get together, understanding their lingo can be difficult for the novice. Here, to help you sort it out, is a brief glossary.

Cat-Back Exhaust 

The cat in this case is a catalytic converter. A “Cat-Back” is a low-restriction exhaust system that leaves the catalytic converter in place, but enhances the flow of exhaust gases from the catalytic converter to the exhaust outlet.


This refers to exhaust headers – the manifolds that mount to the engine’s exhaust ports and connect to the exhaust pipes. Aftermarket headers are designed to reduce restrictions in the exhaust and help draw out the hot exhaust gases more quickly. This can help increase power.

Cold-Air Kit 

Colder intake air is denser and can help an engine develop more power. A cold-air kit dispenses with the factory air cleaner and ductwork, and replaces it with a low-restriction air filter, usually mounted in an area of reduced engine heat.


Some people like the clean, uncluttered look of a car with no make or model emblems. Debadging the exterior involves removing all of these factory badges.


This stands for Japanese Domestic Market, and it refers to parts and components that generally are not available in the U.S., but may be available on special-edition Japanese-market cars.


The ECU is the Engine Control Unit. In modern cars, it oversees the operation of every aspect of the engine.


Also called remapping, reflashing is a way to reprogram the ECU. Since the ECU controls fuel, air, spark, and more, reflashing is a way to change the operating parameters of the engine.

Boost Control 

Turbocharged engines compress the engine’s intake air. This is called boost. Some modified cars are fitted with driver-selectable boost controls that can vary turbo boost based on the driver’s desires and the grade of gasoline being used.


A supercharger is basically an air pump that’s driven by the engine. It compresses intake air, which allows the engine to use more fuel safely to make more power.


A turbocharger uses exhaust gases to spin a turbine, which is attached via a shaft to another turbine that compresses the intake air. There are many variations in turbocharger size and design that can help increase power at different points in the engine’s RPM range.


When a driver of a manual-transmission car downshifts – selects a lower gear – engine speed has to increase to match the new ratio and the speed of the car. By blipping the throttle during a downshift, the driver can increase engine speed just enough so the downshift will be smooth, and the engine will be at the right RPM for the new gear ratio.

Racing vehicles shown are driven by professionals on closed courses. Do not attempt.

All Subaru vehicles sold by Subaru of America are designed and built for normal driving conditions. The Subaru Limited Warranty, as well as the Subaru Added Security program, exclude damage or failure resulting from modifications or participation in competition or racing events. See the Subaru Warranty and Maintenance booklet for further details.