[luckythirteen13]

Originally Posted by Fobra

This is what a shop tuner had to say about it:
Lets assume IAT is 100 degrees now with meth it drops to say 70 degrees.

IAT sensor after injection

We tune by removing fuel for the Meth in the tune AND the fuel the computer adds for the lower temperature. If the meth fails you are at 100 degrees and have the needed fuel MINUS the fuel we added for meth -- result LEAN BOOM!

IAT sensor before injection

We tune by removing fuel for the Meth in the tune for the sensed temperature of 100 degrees. If the meth fails you are at 100 degrees and have the needed fuel MINUS the fuel we added for meth -- result LEAN BOOM!

i wouldnt ever go back to that tuner again. he doesnt know sh*t. if the iat sensor is after the injector and you tune for the meth WITH THE IAT, if the meth fails, the iat will know and compensate by adding fuel and pulling timing. if your tuner doesnt do it this way, stay the hell out of his shop!

in other words, if the meth sprays, the iat see that (because temps are lower), and the computer pulls fuel and adds timing because it can when the meth is spraying. if the meth fails, the iat will see that (because temps are higher) and the computer will dump more fuel and subtract timing because the meth is not present. that is the correct way to tune for meth injection