Toyota Corolla AE86 GT Turbo

The first trials were made with the early spec 4AGE engine, keeping the boost up to 0.5bar (7 PSI). The boost was then increased to get power figures closer to 200hp and just to play it safe, the engine's bottom-end was replaced by one from a 4AGZE.

The camshafts were kept original but with the timing slightly changed to improve low rpm torque, making the turbocharger boost earlier!

Tests were made using a KKK from an Alfa-Romeo and a Garrett from Vw Golf td mk1, but none of them was used for long as one was faulty and the other wasn't too good either. The next available choice... the Mitsubishi TD04 13T-4 that is still "boosting" at a constant 0.9bar (13 PSI).

The intercooler was taken of a Mercedes Sprinter and it's just... massive!... It occupies literally every bit of the front of the car.

A custom exhaust manifold was made small to level the turbocharger roughly at the same height as the exhaust ports, however that doesn't help the airflow, so it will be replaced.

The exhaust is made of a 2.5 inch stainless steel pipe all the way to the back, with a Lambda sensor installed on the down-pipe for rough monitoring the air-fuel ratio (not wide band).

The Webber-Marelli IAW045, from a Ford Sierra Cosworth, was chosen to substitute the original ECU, as this unit is easy to reprogram and because it was also available at the time.

Some modifications were required to the distributor's sensors and a crank sensor had to be added.

The throttle sensor had to be rewired because the original ECU has an inverted functionality, at full throttle one has a ~4.5volt signal to the ECU while the other has to have ~0.5volt, and vice-versa for idle. This was achieved by inverting the power to the sensor.

The Water and Air temperature sensors were kept the same as these have a very similar temperature versus impedance plots as the ones used on the Cosworth.

The MAP sensor was replaced by a 2bar Magneti Marelli.

The Boost control valve also called Amal valve came from a late Escort Cosworth.

The idle valve is a Bosch unit from an Opel 2.0L

The ECU wiring harness uses most of the available features of the ECU, for example there is, originally on the Sierra, a service connector that allows you to change the timing of the ignition by a few degrees according to the type of fuel used (ex: 95, 98 and 100 Octane). The trick here was to setup the ignition map to the highest octane fuel and then use the service connector to select from the four possible ignition retard settings. Two wires (connections) are used, which can be off-off, off-on, on-off and on-on, respectively, 0, 2, 4 and 8 degrees subtracted to the ignition map, making it possible to use lower octane fuel, to a certain point, without the risk of knocking.

Also installed is an easy access switch that makes the ECU start a self diagnostic, which is good when for some reason related with the sensors, the engine doesn't start or stops working.