i want to learn about tuning, i guess this is a start.



1) what are maps (injector,ignition) ?
2) what does stand-alone ecu mean ?
3) what is a wide band 02 sensor for ?
4) what are closed loop systems ?
5) what are duty cycles?



thanx for your time.

 

A map is a matrix of pre-set (or user-set) values that the ECU uses to run the engine. As you may expect, an ignition map is for the ignition, and the fuel map is for fuel. Most of the modern maps are 3D, which means they are graphed by rpm x load x ignition or fuel value. Some maps are 2D, which means that they are only rpm x ignition or fuel value. Sometimes the 2D maps are made into a pseudo 3D system by providing several 2D maps to be used at different load values. See a 3D map here:
http://www.redlinerotary.com/wolf.htm
You can download some old software and maps to play with, as well as the manual. You will need the software labled "Wolf Memory Cartridge Software".
http://www.wolfems.com.au/wolf_downloads.html

Stand-alone means that the ECU doesn't require the car's original computer in order to run the ignition timing or fuel injection. This is in contrast to a "piggy-back" unit that works in conjunction with the stock computer.

Any O2 sensor is for determining the air/fuel ratio of the engine by reading the amount of oxygen in the exhaust vs. the amount of oxygen in the outside air. This information can be used by the ECU to keep the engine tuned during idle and cruise, and some day technology will allow for it to tune the engine during acceleration and deceleration. The O2 sensor may also be fed into a monitor so that a mechanic can use the information as a tool when tuning the engine, or for the driver to monitor the air/fuel ratio when driving. A narrow-band O2 sensor reads the air/fuel ratio accurately when the ratio is close to stoich (chemically correct ratio for economy), but not so accurately at ratios beyond this point. A wide-band O2 sensor is more accurate through a wider range of air/fuel ratios, which is good for performance tuning that requires air/fuel ratios on the richer side of the scale from stoich. The common scale for unleaded pump gas is rich = 10:1, stoich = 15:1, lean = 20:1. Ratios are by weight, not volume.

Closed loop = O2 sensor input is used by the ECU to run the engine.
Open loop = pre-set values stored in the computer database (maps) run the engine.

http://www.sdsefi.com/techform.htm

You may like these sites also:
http://www.rceng.com/technical.htm#WORKSHEET
http://www.grapeaperacing.com/GrapeA...linjectors.cfm

 

thanx dude that really deconfused me