Rev Limiter kill switch/ working around the ecu, Adding variables to a factory ecu Options

[Agent21]

Ok so I know there is a happy little pulse width modulation signal that goes to the ECU to tell it how fast you are going. I have heard this is a purple wire with white tracers. I have heard you can cut this wire or add a chip to reduce the pulses and lie to the ecu. I know it triggers the cel but I have suspicions it throws the ECU into safety mode as well. Anyone got better info?

This post has been edited by Agent21: Nov 8, 2005 - 11:22 AM

[Agent21]

Well legal is sorta a question we are raising. The guys with Carbs can rev their motors till they blow so why can't we? Last I heard from the MR2 guys the 4AGE can be altered be altering the clock crystals and the 5sfe can be altered by simply cutting said purple wire with white tracers. You pretty much brought up the same concern as I did earlier about the ECU going into safetly mode. Now in our case the only time we would be below I'd say 5000 rpm would be during pace laps and entering and exiting the pits which our heat races don't usually include unless something went BAD wrong. Really if I could change the clock rate of the ECU it would be near ideal. It would run the engine a little richer I believe because it will think the car is at a lower RPM then it really is. Taking that into consideration since we already need to run the car much richer we can then adjust with the right injectors. Now comes a really tricky part I know I can alter the timing slightly with the temp sensor by making it a variable resistor. Essentially raising or lowering the temp it thinks it is outside to advance or retard the timing HOWEVER we do need an correct reading for the actual gauge in the car to make sure we don't cook the engine. Really I know I am trying to do all this the hard way and an aftermarket management system is the way to go but really I got no choice and if I can get this to work there will be more Celicas on the circle tracks.

This post has been edited by Agent21: Nov 8, 2005 - 9:56 AM