bad96firechikin

I think I've about decided to go with either the METCO or the TPIS unit....how hard is it to install these type that modify the stock one?

magius231

AlexA, reading at your post from a week ago (or whenever) it looks to me like you state that an AFPR won't do anything for you...in fact Injuneer points this out as well, but I notice no response from you on it...?

If you adjust the AFPR and pull out fuel pressure, the PCM will begin adding fuel to reach its ideal AFR. When you go WOT, this added fuel is added into the WOT BLM as well...which is exactly what you state. So the only way you could get around this is by making the car run even more rich, as it won't add that into the WOT BLM, but that would be bad since we all know they already run rich as hell...

AlexA

Well, it depends on what you trying to do! Are you trying to lean out or richen WOT? Bad way to do it and if you're not careful, the PCM WILL compensate. Do you want to raise fuel pressure to compensate for injectors that are too small? An injector will act "bigger" with higher fuel pressure which is useful if you are encountering a duty cycle >90%. Are you trying to lower fuel pressure for better atomization? Yes, part-throttle will be adjusted to 14.7:1 no matter what you do (within bounds, of course), but there are valid reasons for an AFPR. I'll give you mine :

I put a Racetronix fuel pump in the car in preperation for nitrous. The new pump increased fuel pressure to 46/50 (non-WOT/WOT). So, for better atomization and the fuel pressure at WOT that I tuned the car for originally, I need to bring the fuel pressure down to ~40/43 (stock). In the mean time, I leaned the car out about 10% at WOT to give me a reasonable AFR. This was done on the dyno with WBO2s. Once the AFPR is on and adjusted, I will undo this change and be confident I am runnin the injectors at their intended fuel pressure and that my AFR is on the nose.

BTW, I replied to Injuneers post. It seems to have been my ****-poor "tired" post that wasn't very clear.

-Alex