The main reason that 8 injector setups existed in the first place was all down to induction stroke timebase and injector flow required versus the resolution needed at idle.

Basically older injectors arent as quick to respond (open and shut) as modern injectors.

Now at high rpm you dont have long to get the fuel into the cylinder, so you need a BIG injector, but then this means when it will only open and shut at a certain speed you end up over fuelling it at idle and low rpm, cause the injector has a imnimum fuel delivery per operation thats simply too high.


To get round this, you use 2 banks of injectors, and 1 bank only operates at higher rpm, that way you can still use small injectors in the first bank and maintain a good idle.

Read the "803" topic on here for a lot more info on this

https://passionford.com/forum/viewtopic.php?t=157305