Hey guys,

So I have been looking at all these ebay resistors and I KNOW they add fuel... so here is my theoretical question which might actually somewhat work.

If you could add a resistor in the IAT wire which ONLY turns on when boost comes on (by way of a boost pressure switch) then it would only add fuel when it is on boost and in no other time.... ??

Also, you could tune it by adding different resistors (add more or less fuel)...

Think positive, could it work? (on a 6psi boost set up by the way, nothing to fancy)...

Theoretically? KEEP IN MIND JACKSON RACING USES THIS SAME EXACT METHOD FOR SOME OF THEIR BASIC INTEGRA AND CIVIC SUPERCHARGER KITS (iat resistor triggered by a boost switch)

 

What your describing will work on paper, as long as your droping voltage on the IAT signal input line via boost press switch then yes injector pulse width will increase. But the AF ratio will be all over the place, remember fuel requirements are different at 4k and 9k rpm even if boost pressure is constant. Or lets say the efficiency threshold of the turbo/sc or intercooler is reached, at this point IAT will be hotter than normal at 9psi (random #,an example), wrong IAT signal is sent to the pcm, injector on time is decreased. With high combustion temps and you will be running into engine knock.

What your describing is similar to a rising rate fuel press regulator which is known as "FMU", but instead of adding fuel via duty cycle it does it through bumping up pressure depending on intake manifold pressure. Both methods are not the best way to do it as there is no way to fine tune the fuel mixture and ignition timing is left the same. I have used the fmu method in the past.. 6-7 years ago but once you go with a real management system you will never look back.

 

It would not work. It is changing your timing advance too. It will trick it into thinking its running cooler so it will change the map and bump the timing which would be bad under boost.