idea for the technically minded

[twilightprotege]

well those hos email "chips" have got me thinking.

if anyone is unsure about what i'm talking about with the famous ebay chips, basically they are a resistor. they go in between the positive and the output wires on the air temp sensor to fool the car into thinking it has colder air coming in. why is this bad for us? well for most cars when you modify them they tend to be a little lean at high rpm. having the ecu think it's getting colder air means more fuel injected into the engine. for most modified cars with stock ecu, small power boost.

now the problem we have, esp in the BJ's, is that the cars run flippen rich at high rpm. so doing this "chip" would make less power than before. anyway, using the idea of resistors, we could do a test (on dyno with true a/f ratio readings ofcourse) and put a resistor inline on the output from the MAF sensor to fool the car into thinking it's getting air than what it really is and therefore, less fuel.

but wouldnt this make the low rpm even leaner than what it already is? well no. at low rpm, known as open loop, the engine uses all sensors to determine the best amount of fuel to inject into the engine. but this is where our cars are good. the ecu will trust the o2 sensor over the maf to work out the ratios. so changing the maf by a little bit wont hurt. at high rpm when the ecu goes into closed loop, it only uses the air temp and maf sensor to work out the amount of fuel to use. that's right, not even rpm. rpm is used to fire the injectors and that's it. the ecu has a predetermined "safe" amount of fuel to inject for the amount of air sucked in. when it's an injectors turn to fire, it fires blindly so to speak.

so, if with testing on a dyno and reducing the amount of air the ecu thinks it's getting, i could have a winner a very very cheap mod which should yield decent results.

but there is a downside, and this is where i dont have electronics knowledge so correct me if i'm wrong.

there are several types of resistors right? ones that take out percentage of voltage, ones that take out a fixed voltage, and ones that limit voltage. is that right?

anyway, where do i start to work this out? who can help moi?