Story By Retromod Staff
Photography by Mason Bleasdell • www.bleasdellphotography.com
The car hobby is as much about the people as it is about the cars, if not more so. Over the years we make countless connections thanks to our shared love of cars, some enduring and some more temporary. In a lot of ways automobiles serve as a metaphorical campfire for connecting with others who share similar interests. They're as much of a vehicle for getting us down the road as they are for forgoing strong connections with the folks around us.
Aaron Bunch and his turbocharged Ferrari 308 is an excellent example of how influential people can be on us as we evolve as a car enthusiast. If it wasn't for a childhood friendship, Aaron wouldn't even own the 1978 308 GTS pictured here.
“The 308 belonged to a long time family friend from Wichita Falls, Jason Christie,” says Aaron. “He was THE guy who got me into cars.” Though Jason was a few years older than Aaron, it didn’t stop the two from developing a friendship which would be based largely around cars. “Our parents knew each other and we would visit them about four or five times a year, usually around the 4th of July.” When Aaron was 13, Jason took him for a ride around town in a 1959 Austin Healey 3000 and over the next few years introduced him to more cars, including a 5.0 Mustang GT and a couple of Corvettes. “Jason wasn’t just successful with cars,” says Aaron, “he was a good student, soccer player, karate master and had beautiful girlfriends. He was the kind of guy that every guy wanted to be.”
Over the years, the two friends lost touch and got busy with careers and their growing families. Aaron also had his hands full running his busy auto shop, ATS Racing in Denton, Texas. One of the last cars Jason bought was a 1978 Ferrari 308 GTS. "We hadn’t spoken much over the years, but our last conversation had been about his 308 and the things he wanted my shop to do to it,” recalls Aaron. In 2006 he got the terrible news that Jason had died in a plane crash. “After he passed away I contacted his family and asked what would happen to the 308. Jason’s dad, Robie, agreed that I would be the right buyer for the car.”
Unfortunately for the Ferrari, it had been sitting outside under a carport with the windows down for a couple of years. “Water didn’t get in it but dirt and dust certainly did,” says Aaron. “It also didn’t run and puked gasoline when we tried to start it.” The 308 still had its original carbureted, 2-valve V8 engine and despite being extremely dirty was in solid condition.
The 308 became part of Aaron’s growing collection of sports cars, which currently includes a 1984 Porsche 928 S, a 1990 Porsche 928 S4, a 1990 Lotus Esprit SE and a 1988 Callaway Twin Turbo Corvette. At his Denton, TX shop, ATS Racing, Aaron is actually a Toyota MR2 specialist. When he’s not busy building high performance MR2s for his customers, he has fun with his 1000-bhp turbocharged MR2 as well as his 180-bhp 1988 supercharged MR2. With a preponderance of turbocharged cars in his garage, Aaron obviously has a thing for forced induction.
While Aaron’s childhood friend was in large part responsible for Aaron’s love of cars and is the person who led him to Ferrari ownership in the first place, there was another individual who would end up greatly influencing the direction of his 308 project. Bob Norwood is a name that is familiar to most Ferrari enthusiasts thanks to the turbocharged Ferraris hes been building for years, not to mention all sorts of other endeavors involving the Italian machines. “I met Bob in 2002 when I bought a MoTec ECU from him for my Toyota MR2,” says Aaron. “Bob had worked with Sport Compact Car and their MR2 project, so I knew of him through magazine articles.” Norwood was very helpful in setting up the ECU on the MR2 and even taught Aaron how to tune the car himself.
Over the years, Aaron and Norwood’s paths crossed at various car shows that Aaron had taken his 308 to. “I ran into Bob again at the Texas Invitational Runway Rivalry Race in 2014.” Bob recognized his blue 308 and the two got to talking. “Something about being around Bob and all the 2000-hp Lamborghinis at the event really stirred something up," says Aaron, who paid a visit to Norwood’s shop the next week. “I told Bob I wanted 300-hp in my 308. He laughed and pointed at my 1000-bhp MR2 as an example of me not ever being content with 300-bhp." Before he knew it, Norwood had convinced Aaron to remove the 308’s original motor and store it in case he ever wanted to take the car back to stock. In its place would be a turbocharged Ferrari V8 based on a 308 block and better breathing 4-vave heads from a 348.
Aaron started with a stock forged crankshaft from a 308 Quattrovalvole, which he micro-polished on Norwood’s lathe. The crank was then slipped into the 308 block that Norwood had supplied him with. Carillo connecting rods were than bolted to JE pistons made specifically for Norwood. “They have quite a bit of dome and are very high compression,” says Aaron. “We knew we would be running E85 as fuel and could handle the compression. We estimate it to be about 12:0:1 compression ratio.”
The 348 cylinder heads were worked over for better airflow before being fitted with four re-ground 348 camshafts. To ensure that the heads mated securely to the block, Norwood copper headgaskets were installed along with steel O-rings in the block that fit into receiver grooves cut into the cylinder heads. Ferrari 328 intake runners were port-matched to the 348 heads.
On the fuel side, Aaron installed Trick Flow 60-lb fuel injectors. “The rails were cut and drilled by Norwood but all of the modifications to mount and install them in the intake runners were done by me,” he says. A special Norwood throttle body spacer provides additional clearance for the injectors and the 70-mm throttle body with a Toyota throttle position sensor.
By far the most exciting aspect of the build is the turbo system that Aaron engineered for the Ferrari. When he initially called up turbo specialists Precision and told them he was building a 600-hp 3.0-liter engine at 1 bar of boost, the company responded skeptically. “Most turbo 3.0-liter motors make about 450-hp at 1 bar of boost,” says Aaron. But in the end they delivered, providing him with a Precision 6265 with a .82 T4 exhaust housing and a billet compressor wheel. “The hot side of the turbo kit (manifolds, etc.) was actually very simple,” says Aaron. “I used Ferrari 328 exhaust manifolds and a stock 328 mid-pipe that Y’s the manifolds together under the trunk. From there we fabricated a J-pipe that went forward and up to the turbo.”
In order to cool incoming air an intercooler was a necessary aspect of the turbo setup. However, space is at a premium in 308 engine bays. The solution was a large water-to-air core in the trunk with an electric water pump on the right side of the trunk. There is also a separate radiator for the intercooler mounted between the exhaust tips and a one-gallon reservoir integrated into the top of the intercooler core. All told, the system contains about three gallons of water.
“The exhaust system after the turbo is a 3-inch mandrel bent stainless pipe that leads to an electric exhaust valve that I can open with a switch hidden in the ash tray for more presence,” Aaron continues. “The left exhaust tip is unmuffled and only flows when the valve is open. When the valve is shut the exhaust passes through a 3-inch muffler on the it’s way to the right tip.” On the cooling end of things, a universal radiator from Summit Racing was modified to locate the inlet and outlet pipes correctly. Dual 9-inch Maradyne pusher fans replaced the original fans.
More Toyota parts can be found in the ignition system, which uses a coil on plug setup cribbed from a Tundra pickup truck. The Link G4 Storm engine management system is a mix of components. “Most of the sensors are from OEM applications,” says Aaron. “Water and air temp sensors are GM Corvette stuff. Manifold pressure, TPS and idle air controls are Toyota MR2.” A Ferrari crankshaft position sensor was also used, along with Norwood cam position sensors and magnetic triggers. When the Ferrari was strapped to the dyno with it’s new driveline, it didn’t disappoint. The turbocharged Italian V8 pumped out an impressive 572-hp to the wheels, with an equally impressive 418 ft-lbs of torque. "On my dyno a Ferrari 308 and 328 exhibit a 19-percent drivetrain loss," says Aaron. "So I don't think I'm exaggerating when I claim 700 horsepower."
With that much power, Aaron wisely turned his attention to beefing up the rest of the cars mechanical systems. “The clutch is a crazy collection of parts,” he says. “A stock pressure plate was modified with centrifugal weights to increase clamping pressure at high RPM. The clutch disk is a carbon-kevlar unit with a higher coefficient of friction than normal organic clutches. The bad news is that we are currently power limited by the clutch.” Norwood rebuilt the Ferrari’s 5-speed gearbox, which so far has held up the abuse of the turbo motor.
In order to sharpen up the chassis, fully polyurethane bushings were installed along with fully adjustable QA-1 coilovers with slightly stiffer than stock springs. The chassis has been lowered 3-inches. “The ride quality is still great and the lower center-of-gravity handles well,” notes Aaron. The front rotors and calipers are from Girodisc, while the rear calipers and rotors are larger items from Superformance. The original 14-inch wheels that came on the Ferrari when it was new have been replaced with more performance oriented Autostrada Modena wheels that measure 17x8.5-inch up front and 17x9-inch at the rear. Tires are Toyo R888s that measure 225/45R17 and 255/40R17.
"It handled the power pretty well, but I had to upgrade the tires to R888s to keep traction and improve braking." The 308 is blessed with one of the most beautiful sports car bodies in existence, so Aaron was judicious with the changes in that area, with changes limited to a more aggressive 288 GTO style front airdam, bumper, turn signals and foglights, the latter sourced from a 1988 Camaro IROC. Needless to say, Aaron is pretty pleased with what he has created with his friend's old 308. "Before the car was fine," he says. "It made great noises and handled great. But now the car is amazing."