1When it comes to discussing engine management, the amount of fuel which is injected into an engine gets pretty well all of the attention. Is the engine running rich or lean? Is a bigger fuel pump needed? Are the injectors okay? But when it comes to performance mods, the amount of ignition timing advance is just as important. The exact time that the spark fires relative to the movement of the piston helps determine whether detonation (knocking) occurs and also has a big influence on the amount of power that's developed.
But changing the ignition advance curve (especially in engines that don't use a dizzy) is not easy. In many cars, a new chip can be written to give the required changes, but this puts all of the decision-making into someone else's hands - and anyway, some cars are simply un-chippable.
But now there's apparently a solution. The A$650 Icon Race programmable ignition timing computer is said to give easy control over the ignition timing.
Just released in Australia by Powerchip, the device has been developed by UK company Superchips. The Icon Race is an interceptor-style box. This means that it takes the ignition timing signal coming out of the ECU and advances or retards it as the user requests. This results in the spark advance angle also being retarded or advanced.
So why would you want to change the timing? If the car is aftermarket supercharged or turbocharged, the factory ignition timing will often need to be retarded if detonation is to be avoided. In another case, naturally aspirated cars running fuel upgraded to a higher octane (eg from ULP to PULP) can sometimes tolerate more ignition advance without detonation and give a bit more power as a result.
Fitting
Powerchip made available a 1.6 Mazda MX5 fitted with the Icon Race. The device is wired directly to the board of the Mazda Electronic Control Unit (ECU), with this process being carried out by Powerchip. In addition to the small Icon ECU, a floppy disc of software and a PC > Icon link cable is provided.
The Icon uses a number of LEDs that indicate the status of power, input and output signals. However, in actual use, these LEDs are not really needed.
We had Powerchip set up the software in our laptop PC but this step looked straightforward and so shouldn't cause a problem. Note, however, that the Icon software must be run from the DOS prompt - not in any form of Windows. The Icon is powered directly from the vehicle's ECU and so no further wiring connections are required.
Using It
What the Icon allows you to do is quite simple: from the factory settings, ignition timing can be advanced or retarded by up to 20°
at 400 rpm intervals from 1200 to 7200 rpm. However, unlike a "proper" programmable ECU, the selected Icon ignition timing is not load sensitive - you can't set the ignition timing to be retarded only at high loads, for example. This means that the processes that the factory ECU uses to determine the correct ignition timing still occur as usual, but the end result is retarded (or advanced) by your selected number of degrees at each rpm.
The software comes with suggested ignition timing advance modifications for a variety of engines, including Toyota, Honda, Volkswagen, Rover, Mitsubishi and Mazda.
While at first glance this looks impressive, the actual timing changes which are suggested are pretty simple. For the Toyota 3S-GE for example, the suggested timing changes are a gradual increase from 1200 rpm until +4.5°
is reached at 4000 rpm, with a further increase of another 0.5°
from 6000 rpm.
These suggestions are based on British fuel and engines and so doing your own testing in your own car with the fuel that you intend using is likely to give much better results than the suggested maps.
Making the ignition timing changes is dead-easy. On the graph that shows the "race map", all that you need do is to use the arrow keys on the keyboard to drag up or down the advance/retard line. Once the changes are as you wish, hitting the 'enter' key sends them to the Icon Race. After about a second's delay, the click of a relay can be heard and the new timing is then functional. Incidentally, the car doesn't fart about in the interval between pressing the 'enter' key and the click of the relay; the Icon just reverts to the manufacturer's timing during this time.
Test Results
It was suggested to us that the Mazda MX5 would respond favourably to some further ignition advance. The Icon suggested extra advance is a gradual increase from 1200 rpm until +3°
is reached by 2400 rpm. This extra advance is then held until the redline. Wayne Besanko of Powerchip said that he had found that this could be modified slightly for better results, and dialled-in a slightly changed ignition advance for our car.
When we up picked the car it was using normal unleaded petrol and running the Powerchip advance curve. And it detonated. Not in normal city driving, but when we undertook our performance tests (with repeated full throttle use) soon the distinctive "ting, ting" was occurring on every gear change. It should also be noted that the air temperature was quite cool - around 15° C.
Using the Icon we returned the timing back to standard and put in half a tank of premium unleaded. As expected, this removed the detonation problem and so we carefully started dialling-in more advance. Measuring the Mazda's performance with a G-Tech accelerometer, we were laying down 0-100 times of around 10.8 seconds (two-up and on a slight incline).
Adding as much as 3°
timing from 2400 rpm made no measurable difference to the 0-100, so we changed tack and instead measured rolling splits of 60-90 km/h in second gear. This timing split is much easier to get consistent, because it removes the necessity for getting the launch exactly the same each run.
With standard timing, we measuring the rolling 60-90 km/h at 3.2 seconds; with 3°
extra advance from 2400 rpm it was slower at 3.3 seconds, and with +5°
from 2800 rpm it remained 3.3 seconds. The timing was certainly being changed: note-taker Michael Knowling inscribed "acceptable small detonation after gear changes" with the +3°
timing curve in place.
Conclusion
The Icon is easy to use and changes the timing in the way it is supposed to. This means that the product lives up to its claims and can be recommended by AutoSpeed. However, if you expect big power gains on a naturally aspirated engine, you may be disappointed. We see the major worth of the Icon Race being in forced aspirated cars where detonation has become a problem. In this situation it is a cost-effective way of pulling back the timing.
Contact:
Powerchip
+61 3 9510 2825
www.powerchip.com.au
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