karpetcm

What to buy a adjustable fuel pressre regulator and not sure how about my 94Z. Just wondering ive gone this route before on my 93Z and it worked perfectly and would stay at what i would adjust it at. Major help using nitrous and tuning on the dyno. I dont know how my 94Z will do, ive heard that many times you can adjust your fuel pressure regulator but at WOT the computer will re adjust and add fuel accordingly but that wasnt the case on my 93Z how are the 94's in comparison. Can you add a fuel pressure regulator and adjust it at a giving PSI and it will stay there without the computer re adjusting it. Thanks in advance

seawolf06

The computer will readjust at all throttle positions. Don't waste your money on a AFPR. Get a tune.

Injuneer

The PCM will not adjust the fuel pressure - it will stay exactly where you set it. But it will start to modify the long term fuel corrections, negating the change, or possibly making the engine run richer at WOT - depending on whether you raise or lower the pressure.

You do not "tune" with an AFPR. You use it to change the flow rating on your injectors, and then you have the PCM reprogrammed for the new injector flow rating. I'm also not sure why it would be a benefit for nitrous applications, since you want to tune the engine for best performance without nitrous, then use external means (fuel jet in a wet system, or using nitrous pressure applied to the FPR for a dry system) to provide the extra fuel when you spray.

96capricemgr

Look at an adjustasble regulator as a fuel system component, NOT a tuning tool. On a 93 "dumb" system you might have been able to see some gains but you will see less with the "smarter" 94+ pcms. If you don't like the tuning in the car change it in the pcm, not by altering other things.