Aux injectors on the G4+ plugin

[motomattx]

Hello everyone, been browsing for a few months since buying a G4+ plugin, I have been using Ecuflash on a stock Dsm/Evo ecu for years now and finally made the jump to standalone and the Link setup seemed to be the best bang for the buck out there, I havent seen alot of Dsm/Evo guys at the big events running it yet but I know a few are and it seems to be catching on, and I intend to suggest it to others and I'm looking forward to learning the ways of the system and exploiting its many features for my use as much as I can.  My question for today is, can the plug in G4+ for the VR4/Evo 1-3 run 8 injectors or does it require an aux injector driver setup of some kind?

[Adamw]

The Evo 3 plugin only has hardware for 7 injector drives onboard and some of them are already used for other functions - for instance Inj 6 is used to drive one of the fans and inj 7 is used for the CE light.  If you wanted staged injection you would probably have to do it in group fire mode.

[motomattx]

Ok, so I would fire all four together on one channel but I would need an outside driver box? or can the ecu's injector driver handle the impeadance of the four of them in series or parallel or series parallel depending on the specific injectors? of course in series it would sum the dead times together I'm thinking.

[Simon]

Ideally avoid wiring the injectors in series, If high impedance then you can do up to 3 injectors per drive in parallel.

Low impedance would be a push at 2 per drive. 

Assuming 8 injectors then primaries on to drives 1 and 3 and then the secondary on drive 2 and 4. Two injectors per drive. 

Then run as group staged

[motomattx]

Bringing this back to ask if I could in theory tie my 4 aux injectors in series to my main injectors on the trigger side and then us a relay to only apply the 12v B+ to the secondary injectors under a certain level of map pressure so as to keep the aux injectors in sequenced mode but only use them when needed for the high map level of fuel? I do understand that I would have to lower the numbers in that part of the fuel map at the moment where the aux injectors are brought in of course.

[Adamw]

I think you would get a better result using group/staged.  Switching injectors on via a relay means the fuel table basically needs to halve the pulse width at exactly the same instant that they switch on - that is a lot of room for error.

[Greg W]

Group/staged setup like Simon suggests works good, you can bring secondary injectors  in where you want and as gradual as you need , and adjust for different size and dead time

way better than any secondary controller is going to do