Originally Posted by
Red_bull
it's worth if you're getting not enough fuel. Till that point there is no use of fitting one. So first you can let you car be mapped and see what's going to be limiting you in getting more power out of the engine.
I don't agree with that. Although it depends on what your priorities are with the car.
To increase on-boost fuelling on an MFi car, you screw the off-boost fuelling, so by fitting and mapping the 5th Injector, you can enjoy sensible off-boost fuelling and the 5th injector can take car of on-boost enrichment. Crude, but thats tuned MFi for you.
That's my view on it anyway.