Hello, I've allready done a search on this topic but I never really got the answer I was looking for, but, I was looking at WS6.com and I saw the gains given by the AFPR. I thought it to be very impressive. Then I saw that the computer re-learns itself, and then takes away the gains given by the AFPR. Now though, I am doing a cam install on my Bird. The mechanic that is helping me out said that a AFPR would be somthing great to have on my car. And that it would be a great mod to put on before I get the pcm re-programed. So I really don't know if this mod is even worth it. Can anybody give me any insight? Ohh yeah, I am looking at the AFPR that LS1speed.com is offering. Is that anygood? Thanks.

 

If you alter the pressure, you alter the fuel flow rate. The O2 sensors see the change in A/F ration, and the PCM adjusts the pulse widths to get the fuel flow back where it was.

If you are changing the cam, you need a new PCM "tune". That tune should include adjustments to the A/F ratio at WOT to lean out the overly rich stock programming. If the programmer takes care of the tuning, the AFPR becomes superfluous.... not necessary. An AFPR is useful if you want to squeeze a little more capacity out of your injectors, instead of upgrading to the next size. But it should not be used as a band-aid tuning tool.