Potential Free Mods
 

Ok while I was checking out the electrical diagrams for a typical mod motor I came up with two questions. One is for the resitor in the intake air temp mod. Does a greater resistance equate to a greater advance in timing, and has anybody done this on a96-98 mod motor. I know it shouldnt make a difference on what year but I am just worried about knock. The second question I stumbled accross is, What is the octane adjust plug? Does it tell the computer what octane is being used or supposed to be used. What would happen if you changed that. Personally I dont know too much about the computer and its stock programming and I was hoping some one else could help me out. Thank you

Never heard of an octane adj switch.

On the resistor mod, something to keep in mind is that the resistor does not add timing to your car. Before you can understand what the resistor is doing you have to understand the motor. When cool air comes into the motor the car will not pull any timing or fuel, the warmer the air coming in the great chance of detonation or pinging so the EEC then pulls timing and fuel to prevent this problem. So cooler air equals more fuel and timing thus power, warmer air equals less fuel and timing thus less power.

What the resistor is doing is fooling the EEC into thinking that the air coming into the motor is actually cooler than it really is. So the EEC pulls less timing and fuel because it thinks it's actually cold outside. For track use I've seen as much as a tenth improvement but on other nights it will do nothing. Of course the cooler it actually gets outside the less effective this mod will be. The highest resistor you should use is a 100K OHM 1/2 watt. That simulates like 28-30*. If you leave it in the car it will trigger a MIL after 5-10 cold starts of the car. What happens is the EEC does a random check every so often and compares the temperature of you coolant and compares it to you IAT and if there is a significant difference it triggers the MIL.

What I did for a while that helped on the street is move the sensor, lengthen the wire and put it in the fender. The air in there is cooler than any air being pulled into the filter. It will even get a cooler reading than if you have a cool air kit since the intake piping will warm the air prior to getting into the motor. By having it in the fender and reading outside air it will be within range to not set off the MIL and enough to help out a little on the street.

Bill