I just had my P1SC installed and I am curious about tuning it. I used the adjustable FMU that ATI supplies, but I also have an AFPR. While tuning the car do I play w/ both of these or just the FMU. Any info. on this subject would be greatly appreciated.

 

since your AFPR is usually adjusted pretty close to begin with, and it mainly controls base fuel pressure without the boost (all motor), I like to mainly adjust the FMU. if on a dyno you find that you cannot get rid of a dead rich condition at full boost at high rpm, try diconnecting the vacuum reference to the AFPR (plug the line too). They can sometimes close off return (like the FMU) all the way which circumvents the FMU's activities. if this is the case then get an orafice similar to the little white one on the FMU (included) looks like a little white vacuum fitting from the autoparts store. they are sold by the same company that sells the "HELP!" parts and found in the same catalog. If you cannot find this then try a .015" nitrous jet (or other really small sizes) lubed an shoved into a piece of vacuum line. this works as a buffer to the vacuum and boost signals delaying the activity until after the shift.

 

thanks for the help man. I'm going to have my car dyno tuned Friday, so I'll have to see how everything goes.