Though the JZA80 Supra is modern twin-turbocharged vehicle, it is surprisingly easy to work on and simply loves to be tweaked. In modifying my car, I chose what I believe to be the best performing products for the money. At this stage, there is more of a "function over form" mentality . . . go over show as it were. Eventually, I would like to add products made out of more exotic materials such as titanium and carbon fibre for both aesthetics and weight savings. Cosmetic enhancements such as an aerokit, wheels, and tyres are simply not in my budget right now. More power is always a goal and a single turbo kit is planned.
I suppose the first thing you can do to a turbocharged vehicle is to help it breathe easier, so this is where I started. A host of HKS components were used: a Super Megaflow 200 mm intake system was used to replace the restrictive airbox and allow one to hear the factory blowoff valve better, while a Super Drager exhaust with 3.74-inch piping snakes towards the rear of the car. The Drager has a nice, deep tone without droning or being over-intrusive. The ultra-restrictive and heavy catalytic converters were removed and replaced with a 3-inch mandrel bent downpipe. While some have had considerable difficulty installing the downpipe, mine cooperated and we were able to remove and replace in under two hours time.
The purpose of a blowoff valve or bypass valve is to release pressurized air when the throttle plate is closed. If this air is not bled off, the turbine could actually spin backwards, a phenomenon also referred to as compressor surge. It is my, and others', opinion that the factory BOV is not sufficient at BPU-and-beyond levels of boost due to not only the higher pressure but the possibility of leaks due to age. Having said that, my surge prevention tool is a HKS SSQBOV vented to the atmosphere. Venting to the atmosphere, however, creates a rich run condition because metered air is not actually going into the engine, rather it is blown off. I have not had any issues except an occasional stalling when doing a burnout . . . otherwise the car runs very smoothly. At low boost, the factory BOV releases air with a slow psssshhhhh sound, while at higher boost the HKS unit creates a high pitched tone that has startled unwary drivers -the best of both worlds.
At higher levels of boost, say 18 psi and above, the stock turbochargers are presumably out of their efficiency range. Thusly, the air compressed by the stock twins is hotter than what a larger, more efficient turbo would produce at the same boost. As we all know, cooler air is denser air, and one of the ways to cool down the intake charge is through an intercooler. I opted for a GReddy 3-row air-to-air unit with a 24x12x4" core. I chose the 3-row because of the completeness of the kit for the money, the size, and the fact that it did not require as many modifications as its 4-row sibling. While the FMIC did not require significant alterations to the car, saying that the installation was hassle-free would be unfair. It took me the better part of a week to work out all of the details. The biggest mistake was reinstalling the headlights and closing the hood without securing the hood latch mechanism. Well, not being able to open the hood was not that big of a problem, right? Wrong. Especially when an intercooler pipe pops off and the car would run erratically, and not above 20-25 mph. The installation of the front mounted chiller also required the removal of the factory power steering cooler in favor of a new GReddy-supplied power steering cooler. Luckily, the B&M transmission cooler that I installed at the same time as the 3-row did not create as many problems. =)
In another chapter of: Why Didn't We Get That?, is the European hood scoop. The USDM vehicles are equipped with a snorkel to cool cylinders #3 and 4 near the turbos, but is left inefficacious without said scoop feeding it. I decided to install the Euro hood scoop to help out the peashooters as much as possible, and as an added side-effect, to allow more fresh air to flow into the engine bay. Also fitted is an aluminum FMIC panel. Because the intercooler sits in front of the radiator, air is diverted up and over the radiator and into the engine bay. With the panel in place, the air is forced to flow through the radiator and hopefully, keep coolant temperatures more reasonable. The addition of Redline Water Wetter is added insurance. Some good diagrams showing the FMIC panel at work can be found here. As a preventative measure, I installed an upper radiator hose from a 1998 Supra. As you can see, there are two bends or kinks in the hose, unlike the 1993.5-1997s where it was just one curved piece. The added rigidity prevents the hose from sagging into and being worn away by the accessory belt. I don't know about you, but I'd prefer not to clean up a bunch of coolant from my engine bay. =)
This area is where my car is most deficient. I wanted to focus on power to back up the looks, not that a stock Supra with polished or chrome wheels is a dud. =) For now, I only have the Euro hood scoop and FMIC to add some menace to the front end. At night, I have one of those cars with the annoyingly bright headlights that my friends don't even want to drive ahead of. I have always loved the way HIDs looked since they started becoming more and more common in the mid-1990s so I fitted a set to 2N TURBO and I will regret the day I have to go back to conventional lighting. It is unfortunate, however, for those trying to be unique when economy cars can be optioned with xenon lamps.
Under the hood, I added a chrome HKS SMF filter cage and SMF Bolt to add some shine to the rather dull intake system. An aluminum Suprastuff.com radiator plate was added to hide the unattractive foam that is used as a seal around the radiator. This plate was hand polished to match the FMIC panel. Though the GReddy FMIC core and its associated hardpipes came fully polished, I took it upon myself to further hand polish them and protect them with a coat of Zaino. After some serious deep drains to the original battery, it gave up the ghost. I figured I may as well replace it with an Optima starter battery.
Again, the interior modifications amount to zero, save for a set of Toyota chrome gauge bezels from Paul Whiffin in the UK.
Full Parts List:
HKS Super Drager 95 mm ExhaustElectronics:
BLITZ Full Auto Turbo Timer<Cooling:
B&M 24,000 GVW Transmission Cooler - 11x6x1.5" CoreWheels/Tires:
TRD Front Strut Tower BraceExterior:
Toyota European Hood ScoopInterior:
The general consensus is that one of the most important things you can purchase for your Supra is a boost gauge. Toyota really left us in the dark by not including a boost gauge - even a graphic system, e.g., blocks, bars, etc, would have been better than nothing at all. Having said that, I purchased an inexpensive VDO mechanical gauge. Somebody at Toyota was really thinking because a 52 mm gauge fits perfectly in the factory clock position. After installing the Blitz DSBC, however, I have not used said gauge as much, rather, I rely on the peak/hold feature of the boost controller.
I decided to go with the Blitz components because of their feature base and diminutive size. The DSBC allows, in effect, five boost settings in addition to a boost limiter that quells boost spikes - a very valuable feature. The FATT lets the car idle from 10 seconds to almost 10 minutes to allow oil to circulate through the turbos to prevent coking, while a built-in voltmeter is an added feature. Both the DSBC and the FATT are 1/4-DIN in size, allowing them to be mounted pretty much anywhere. I opted to go with a Blitz DIN panel that accepts two 1/4-DIN components and a 43mm gauge. Above said panel sits an Alpine CDA-7864 head unit controlling a Rockford Fosgate amplifier and Boston Acoustic sub.
Being a 1997 model, my car threw the check engine light and the accompanying red exclamation-point warning after I installed the RMM downpipe. A local Supra enthusiast built and installed an OBD-II fooler aka oxygen sensor simulator to remove the annoying dummy lights.
I decided it was time to upgrade the braking system after some repeated high speed runs with a LS1 on an undisclosed test track. =P With the speeds this car is capable of, braking is of utmost importance. After reading about and witnessing others tracking their cars on stock rotors, and sometimes, pads, I stuck with OEM rotors with their curved cooling channels. The pads are also Toyota. Since I was replacing all of the brake fluid, I decided it was a good time to upgrade to stainless steel brake lines and Speedbleeders. I highly recommend the Speedbleeders, it really turns brake bleeding into a one-man operation -one doesn't even have to remove the wheels if you are so inclined.
I fitted a beefy Toyota Racing Development front strut tower brace in June 2002. Installation was the proverbial piece of cake, only having to relocate the ignition amplifier module. The bar rubs a touch on a throttle cable bracket, a known issue, and is only a cosmetic problem to me, not a functional one.
This car loves to go through rear tyres. I am not positive how many miles were on the crappy Falkens that came with the car when I bought them, but I had to upgrade -quick. After seeing what tires were available and considering my needs, I settled on the Toyo Proxes T1-S, full tread depth versions of the same tire used in the Speedvision World Challenge race series. Overall, I am pleased with them, they grip well in the dry, good in the wet, but I have not had a chance to really push them to see what sort of limits they have. Note: do not drive on these, or any, tires in the rain when they are worn past the wear bars. To say I was scared when driving around a wet Capitol Beltway on worn Toyos is an understatement.
For the 1320, I have a set of BFGoodrich drag radials mounted on the heavy ol' stock silver wheels. Oddly enough, I was cutting the same or worse 60-foots times compared to the Toyos. I just need more practice with them on days where the ambient and heat index are not 100 and 110 degrees fahrenheit, respectively.