Imagine cruising down the highway in your brand-spanking new '99 Corvette with your girl by your side-who could ask for more. Right out of the box this car hauls a$$ for the $46,000 you just spent on it. A true race ready street performer. As your anxiously wait for some unlucky fool to pull past you, your first victim creeps up making his way from the rear view mirror to the side view mirror finally paralleling his way right along side you. Right before your shot of adrenaline reaches your right foot, you peep over and to your surprise you're gazing at what seems to be a bone stock Toyota Supra. This gets the saliva dripping cause there's no way a stock Supra with 320 horsepower can hang with your C5 Vette-the race is on!.
Of course right out of the hole the Vette transfers the torque from the burly V8 to the pavement jumping a full car length ahead. Expecting to pull an easy bus length in high gear you notice a high pitch whistle that resembles the sound of air rushing through the gap between your girlfriend's front teeth. As the sound draws closer and closer you quickly glance in the side view mirror to look for your opponent and to your amazement the mirror reveals an empty road. Snapping your head forward you notice the Supra's pulling on you like a mad dentist with a pair of pliers. When you finally realize there's no catching him the last thing that runs through your mind is the Supra.
Now everyone has said or heard, " Why buy the expensive car when you can put that money into a nice fast car to make it even faster." In almost every case you never get the "expensive car" left over money when you buy the fast car, all you get is a fast car.
Well, Ben Treynor of San Mateo, California had money to spare to upgrade the performance of his ride. He purchased the vehicle brand new in June of '97 and he originally had plans to keep it lightly modified. With much enthusiasm, Ben explained, "After reading an article in Turbo about a lightly modified Supra making substantially more horsepower than stock, I took my car to Rod Millen Motorsports to have a similar set of modifications done." The one thing Ben absolutely insisted on accomplishing with his ride was the look of a sleeper.
Compressor surge can kill...
Compressor surge can kill a turbo especially on a daily driven car running ball-bearing-type turbos. Considering that the price for one of these turbos can run up in the $2,500 area, Ben depends on a Blitz Super Sound blow-off valve to eliminate compressor surge.
The HKS twin-turbo set-up...
The HKS twin-turbo set-up relocates the turbos higher than the factory models which made it impossible to use the factory air box. The 2JZ-GTE now relies on a pair of Power Flow air filters with three-inch polished aluminum intakes.
Concentrating most of his money on the engine rather than external cosmetics, Ben was able to generate his first stage of substantial horsepower. A year after he purchased his chariot the Supra went from making 296 rear-wheel horsepower to laying 365 to the DynoJet roller.
This was achieved by adding boost pressure via a Blitz SBC Dual Solenoid boost controller. Utilizing the Blitz unit not only allows the factory boost levels to be surpassed, the unit also cut turbo lag down to a minimum. The boost controller is a dual solenoid set-up, which means the wastegate's valve doesn't crack open till a few psi before its max boost. This causes the turbo to spool harder in the low to mid rpm levels. Added boost pressure needs extra breathing room and since the factory downpipe and exhaust system can be a horsepower killer Rod Millen replaced the factory downpipe with a Rod Millen unit and a GReddy exhaust system. Since the car was based on retaining the stealth look, Ben found the GReddy Power Extreme exhaust system the most camouflaged to onlookers.
HKS and the Toyota Supra go hand-in-hand when dealing with engine management and two of the most popular units incorporated to the factory ECU are the HKS Vein Pressure Converter (VPC) and Graphic Control Computer (GCC). The VPC grants removal of the OE air flow meter in place of a speed/density-type system while the GCC entitles the user fuel tuning capabilities through designated rpm ranges. The factory ECU received a ROM-tune by G-Force which enhanced fuel delivery as well as timing compensation for the extreme boost levels.
Just when you thought the ponies stopped here, Ben's addiction to horsepower grew like an unchallenged wildfire. This encouraged Ben to return to Rod Millen Motorsports for a full turbo package. The crew immediately replaced the factory turbo set-up with a pair of HKS 2835 GT ball-bearing turbos complete with two standard HKS wastegates, air filters and exhaust manifold. The new set-up relocated the turbos so it was necessary to replumbd the air intake. Since the factory air intake is like eating steak through a straw Ben opted to use Twin Power Flow air filters with aluminum HKS intake pipes. An HKS front-mount intercooler which replaced the factory side-mount greatly increased the cooling capacity of the turbo system. To conceal the intercooler, Ben cut out a metal mesh grille and had it powder-coated black making it difficult to spot the HKS core through the bumper. Once the car was up and running it was back to the dyno for a quick retune of the VPC and GCC. As the car was commencing its second low boost pass of 17 psi the clutch was unable to clamp the flywheel horses to the rear wheels. Although the second pass was unrecorded, the first low-boost pass was able to generate 480 horsepower which was quite promising.
GReddy boost pressure and...
GReddy boost pressure and exhaust temperature gauges are used to relay vital information to the driver. The exhaust temp readout can help determine if an engine is running to rich or lean and the boost gauge signals if the car is over boosted.
The Supra relies on an HKS...
The Supra relies on an HKS twin-turbo set-up complete with front-mount intercooler and racing downpipe. From the outside of the engine it looks like a race-prepped JZA engine but taking apart the engine would reveal it contains all OEM rotating internals. This seems to work for most Supra fanatics pumping over 600 horsepower.
A Blitz Dual Solenoid Boost...
A Blitz Dual Solenoid Boost controller maintains boosting characteristics. This particular boost controller works great for low to mid range spooling. The reaction time on the controller's solenoids react so fast it's able to hold the wastegate's valve shut until just before max boost.
With the factory clutch tossed Ben had no choice but to locate an aftermarket unit with enough vise pressure to transfer the horsepower. OS Giken, a well-known entity in Japan, was the weapon of choice due to its twin-disc clutch set-up complete with flywheel. On most high-horsepower applications clutch failures occur within the drive straps. The drive straps is what connects the pressure plate cover to the pressure ring. This is the part that comes in contact with the clutch disc. On the OS Giken pressure ring there are no band clamps, just a floater plate in between the twin-discs. Although the floater plate is loud the payback is a clutch with enough clamping force to transfer all the horsepower his Supra can put out.
Since the OS Giken clutch was a few weeks on back order from GReddy, its authorized distributor in the States, the next upgrade was to enhance the suspension on the Supra. Ben stated, "At full boost, the rear would squat excessively causing the rear tires to camber out and lose traction at 60 mph." To solve the problem Ben applied a set of Eibach Pro Kit springs mounted on a set of KYB AGX shocks. Helping out the traction department are four Bridgestone Potenza S-02 Pole Position tires mounted on the stock 17-inch rims. In the rear are 255/40-17s and the front is home to 235/45-17s. Stiffening up the suspension points are GReddy front and rear strut tower bars.
A few weeks after the suspension upgrades the clutch was in and the Toyota was ready to hit the dyno again. After a few 17-psi low-boost passes the Supra pumped out 518 rear-wheel horsepower. Then it was time to address high-boost tuning. The Blitz boost controller had its last preset dialed into 22 psi of boost and after its first untuned high-boost run the Supra spit out 570 horsepower. Once Rod Millen was done fiddling with the VPC and GCC the car's last pull was able to break the 600 horsepower mark netting 618.6 horsepower with 532.8 lbs-ft of torque. This is more horses than Ben anticipated!
Fuel tuning is critical on...
Fuel tuning is critical on any type of engine so this Supra uses a HKS VPC and GCC for tuning the injector pulse width as well a Paxton fuel pump and HKS regulator to handle fuel pressure stability.
The dream of a true street performer isn't always based on buying the expensive car. In Ben Treynor's case, his dream came true in the vision of a stock-looking Toyota Supra built to out perform any "Supercar" at anytime. Considering the internals of the engine are all OE parts holding up against 600-plus horsepower is enough to give this car the respect it deserves-Keep up the good work Ben!