At what point does your N/A ITR "ask" for more fuel? ...I mean, I installed a V-AFC and with the correction of leaning the A/F ratio between -5% - 8%, I got more HP... So what good would a fuel preasure regulator do? I don't need more fuel... I just took some away, yet I see some people installing fuel rails and FPR's on semi stock ITR's rendering good results. Is my thinking backward on this, or does an FPR really mean more fuel delivery?
thanks,
-ryan

 

^

 

yeah FPR is to add fuel, AFC is to take it away where necessary.

Fuel rail wont show any gain unless you are using injectors large enough
to require more volume in the rail.

 

...this makes sense.
So it would be safe to say for example; after an I/H/E install, the V-AFC will need to be re-tuned to apply more fuel?

 

You might need more fuel after that, but it depends on the car.
VAFC cant add fuel.
FPR is needed for that.