The "resistor mod" really does work. The way it works is that it is installed on the IAT sensor and modifies the signal so that the ECU will think it is colder air coming into the engine. This has two effects... it will enrich the fuel mixture since colder air is denser and therefore contains more oxygen and the second effect is it will advance the spark timing accordingly. You will notice the most difference on a car that has I/H/E installed but no fuel mods since the engine needs more fuel to begin with. The reason you have to run the 92 octane gas or more is that the timing is advanced meaning more chance of detonation and engine damage. Note that if 92 octane gas is used on a fairly low compression engine this mod is completely safe but I wouldn't use this mod on a high compression engine for example a Type R.
I have one question since I haven't seen a dyno with baseline for this mod... if the timing is advanced you should get better throttle response and torque at the low end but is the top end affected?
Thanks
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