I've heard a lot of mention, that by changing the fueling by such as a piggy back chip or a apexi SAFC, that the timing is also altered. Can anyone give me more specific details, like which way does what and by what degree.
Cheers

 

Trimming the MAF voltage (as the SAFC does) will alter the apparent load the ecu sees. So if you want to lean a particular zone you will need to trim down the MAF which reduces the apparent load, thereby reducing fuelling and increasing ignition advance. If you want to enrichen a zone, the MAF will need to be trimmed upwards increasing apparent load, thereby increasing fuelling and retarding the ignition.

In reality if you're making only very small changes to MAF voltage, you may not change the load enough to result in a timing change, but large amounts of trim could see ignition advance modification.

If say, you are planning to use such a device on a overfuelled, safely timed car such as an MY99/00 with ae802 ecu then a combination of leaning the fuelling and advancing the ignition may be both relatively safe and beneficial to engine power/torque. Wideband AFR and detonation monitoring would be essential whilst setting up. On the other hand, you could just try getting a ae800 ecu for the same effect cheaper.

Simon

 

Nice one Simon. Tell me more about the ae800. Who, where and how much?