CAR TUNING

These two words, sound like music, don't they?

Although the Supra goes very fast, and acceleration and handling is superb, people still want it to be faster. I don't know why this is, especially when taking into account the number of people who accidentally kill themselves while driving a heavily modded car, but well, let's talk about modifications. After all, I'm modding my car all the time as well.

The standard Toyota Supra 3.0l Turbo, without any modifications has 232 hp. This is when we're talking about the 89+ model. The MK3 models released between the start (86.5) and 89 featured (only) 230 hp.

The first part of tuning involves taking some restrictions on the flow of air and exhaust gasses; stage one is replacing the exhaust system and stage two the air filter. After you got these modifications, you can expect about 259 hp. Not really much of an increase, but this is more the modification to get the car ready for power up.

After you got this basic system, which is able to flow more air and exhaust gasses, you can turn up the boost pressure. This can be done by a boost controller, available as 'manual' or 'automatic'. This so called stage 3, features about 285 hp according to HKS. My configuration which was comparable did about 275 hp, with a boost pressure of 0.65 kg/cm2 (about 9.25 PSI). The HKS boost pressure is 0.77 kg/cm2 (11 PSI).

The next stage can be various, depending on the handling and behavior of your car. Especially the cars equipped with automatic transmission will suffer from fuel cuts because of too high boost pressure. The easy way to get this fixed is putting in a boost cut defender. This is more what I would consider a 'hack'. It works for the time being, but after upgrading you will have to replace other parts, which might make the boost cut defender obsolete (waste of money and time). Another way to get rid of your boost cuts is replacing the air flow meter which is quite limited. This can be done by a very expensive unit called Vein Pressure Converter, or you can replace this air flow meter with one from a lexus 400 series, which has the same electronics, but can measure more air flow. To compensate for this 'invalid' measurement it's highly advisable to upgrade your fuel injectors accordingly. With this so called "Lexus/Riemer" modification, you can supply enough gas for the rest of the upgrade stages. As long as the fuel pump can supply of course.

After you've done this fuel upgrade, it's cool to boost up the turbo pressure a little bit more. Too bad the intercooler piping expand during high boosts. And moreover, the intercooler is a little bit limiting the airflow. Get rid of those items, and get a new intercooler with full metal piping. This will take your boost pressure to about 12 PSI. The other plus you get is the air density. The air will be cooler so more oxygen is available. Estimated power of this configuration is about 300 hp.

If you haven't done so already (I did it at stage 3), it's now time for a programmable fuel computer. This computer let's you enrich or lean the mixture of the fuel and air, so that you got the optimum mixture at all RPM's. My fuel computer was already build in, right after the boost controller. I came from 194 kW to 205 kW, just by leaning out the mixture. The Supra runs too rich namely. This increase was 9 kW, or 12 hp. Quite an improvement by only changing the mixture.

Now the HKS modifications tell you to get the fuel upgrade with their way too expensive airflow meter, the so called Vein Pressure Controller. Good thing we did do the fuel upgrade with the Lexus/Riemer upgrade. Now we go up in turbo pressure. How? you would ask. The stock turbo is good for about 12 PSI. Until 14 PSI you still can run with the stock turbo, but when you would go higher, the only thing the stock turbo would add to your air is heat. And we don't like heat. So get the stock turbo out of the way. There are a couple of options. You can replace the turbo with an aftermarket (racing) one or you can replace the pulley of the turbo only. I would go for an aftermarket turbo, for example the Garrett one. Now set your boost high, at least 15 PSI.

When you want to go up in HP's things are getting more complex. At this stage, the engine parts (the moving parts) are not able to keep pace. You need to replace camshafts & camgears. I'm not known with this upgrade yet, so don't ask me. Haven't looked into it yet too much.

After this, well, you have to use your own imagination on how to upgrade your engine. Take a look at NOS systems for example.

Good luck upgrading your beast and take a look at the links on the left to find out more about certain upgrades.