Torque Developments Blog

Torque Developments International wanted to evaluate the level of difficulty and the effectiveness of increasing the engine performance of a standard Mazda RX8.

The Mazda RX8 is often critcised for poor performance so we considered ways to bolster the existing channels of naturally aspirated tuning methods to provide a cost effective method of optimising the fuel and ignition management to enhance it’s performance.

In conjunction with Mazda Rotary Parts, we initially conducted a base line dyno test with datalogging on a completely standard RX8 to establish it’s performance and engine management characteristics.

Here is the car hooked up to our Rototest chassis dyno:

The performance characteristics were as the manufacturers claimed, but the air/fuel ratio was far too rich and the shape if it’s fuel delivery curve was incorrect as can be seen from the datalogging graph below.

The green line below shows that the air/fuel ratio curve varies dramatically and reaches the excessively rich ratio of 11:1.

We selected the HKS FCON iS as the choice of aftermarket ECU’s for the management of fuel and ignition timing for this application because it is comes with a high quality harness to make connectivity a simple operation, and it’s level of quality and functionality is extremely high.

The main features of the FCON iS over it’s predessessing model FCON SZ are:

• A 25% faster processing speed.

• Built in video output function to monitor engine parameters.

Here are some pictures o fthe HKS FCON iS ECU.

Removing the front cover reveals the connectivity ports and dip switches.

The revere side shows the very high quality femail plug connector

Here is the “plug and play” harness which makes the connectivity very easy:

Here is the harness connected to the standard Mazda ECU:

For testing purposes, the FCON iS was not permanently installed so it was loosly mounted for the ECU tuning processes:

After correctly calibrating the fuel and ignition management we are able to demonstrate a significant increase in torque and power, and an improvement in fuel conumption:

Here are the “before and after” power and torque curves:

Here is the datalogging graph showing the optimised air/fuel ratio. Again, the green line is the AFR:

We have concluded that the HKS FCON iS is a cost effective performance upgrade solution on the Mazda RX8. For the more discerning owners or for those with turbocharged or supercharged models, the HKS FCON V Pro ECU solution is available which has significantly enhanced features and capabilities.

Torque Developments International has released a video of the initial dyno evaluation which can be seen on Youtube at http://www.youtube.com/watch?v=QWj0i-JWr20

Torque Developments International were commissioned to evaluate the engine performance of the Astin Martin DB7, with a view to enhancing the torque.

We already had a wealth of experience of tuning the Jaguar 6 cylinder 4.0 supercharged engine, so we expected to apply some of our learning to the DB7 which shares some commonality with the XJR.

The test vehicle is a stunning manual transmission example in red, having covered a very modest mileage which the owner had previously installed a high performance exhaust system from the catalytic convertor backwards.

The first stage in the evaluation process was to extract some performance and dynamic data from the standard engine using our Rototest chassis dynamometer and DataQ data aquisition centre.

Our testing indicated the following limitations that need to be addressed:

1. The intake temperatures are too high and are uncontrolled (see data log sheet below showing the increase from 43 degrees at low speed on the first run, to 58 degrees at high speed on the 3^rd run).

2. The power and torque drops by 10% over the course of three power runs (see attached performance snapshot – runs 5-7 below).

3. There is an intake restriction before the supercharger (see the green line on the data logging sheet – runs 8 & 9 below).

4. There is a substantial back pressure present in the exhaust system (measured in the down pipe (see data logging sheet – runs 10-11 below)) of almost 1.7 bar (absolute).

5. The air/fuel ratio is very rich.

This is the exhaust back pressure test taken from the down pipes, showing a 1.7 bar (absolute) of back pressure in the exhasut system. That is higher than the supercharger boost pressure!

This is the restriction in the intake system.

This is the intake temperature. Note how the temperatures rise from 43 degrees to 58 degree over only three power runs. Worryingly, the temperatures seem to be uncontrolled and continue to rise the longer that full power is used.

This is the power and torque curves of the standard engine. Note that the power and torque reduces by 10% after only three power runs!

Our testing has revealed that the following critical path should be followed:

1. De-restrict the exhaust downpipes and catalytic converter.
2. Design and manufacture a large capacity charge cooler pre-radiator.
3. Manufacture a less restrictive intake system.
4. Re-check the air/fuel ratio after the above solutions have been implemented.

Following the implementation of the above, if the AFR’s are still too rich we will then consider an ECU solution to remedy this. If the exhaust back pressures and intake temperatures come into acceptable limits, we will then consider raising the boost pressure.

After running the engine is carefully, it was given an oil and filter change and cylinder leakage test.

The next procedure was to calibrate the Autronic SM4 on the Rototest chassis dyno for ECU mapping.

In a departure from conventional “chipping” methodologies that most Tuners tend to use, we quickly identified the Autronics stand alone ECU as being a suitable solution four our purposes.

The Autornic SM4 is highly regarded in the world of professional motorsport as being a very capable and robust ECU solution with the following features:

• Sequential fuel injector control at speeds of up to 30,000rpm
• Comprehensive speed density load sensing, along with exhaust manifold pressure sensing to calculate the true delta pressure accross the cylinder head, enabling very fast and accurate digital assessment of fuel and ignition under dynamic conditions.
• Excellent peak and hold control of low impedence injectors.
• Fully sequential ignition control (cylinder by cylinder compensation).
• Closed loop wide band lambda feedback with 3D target tables.
• Exhaust gas temperature monitoring with closed loop feedback control.
• Closed loop boost control with 3D target tables.
• Traction control
• Launch control
• Over-run boost enhancement (anti-lag).

Here are some pictures of the uprated Escort Cosworth engine fitted: