turbo II injectors Vs fd injectors.

[travellinbob]

Hey people, another random question from me.:rolleyes:
 Can someone please tell me what the rating of the standard turbo Ii and fd njectors are? as in what cc.
 Also as quite alot of people are replacing them with much larger ones, what are the stock ones worth?
  cheers.

[t2rew]

t2=550cc x 4

fd=550x2 and 850x2

[travellinbob]

Thanks for that. So when people upgrade to something crazy like 1600cc secordary injectors, are they running 550cc or 850cc primaries?
   Cheers, michael.

[20B_boy]

Generally I would say people are running the 550s in the primaries still with 1500-1700s in the secondary. Others run 850s in all 4 ports.

Both 550s and 850s seem to be worth good money used as they are popular as upgrades for other jap cars...

[travellinbob]

Cool thanks, so...lets see if I am almost right about this then? When people run 2 different sized injectors do they drive around under light load(on the engine) on the smaller injectors and then when the right foot is planted do the larger set of injectors start to supply a whole heap of fuel? And is this called sequential injection?
 And if that is right then what do people do with say 4 or 5 or 6 of the same sized injectors do? Run 4 injectors at near full duty cycle then when the boost pressure hits a preset amount do the other additional injectors start to work?
    thanks for any help.
  cheers, michael.

[maximtaylor]

Secondary injectors are generally phased in during mid revs. This does vary a little depending on how heavy the right foot is planted. The more right foot, the sooner the secondaries are phased in alongside the primaries.

This phasing is gradual, it\'s not like either set of injectors just work on/off! Any extra injectors need to be driven by some form of additional injector driver, or a more top end ecu that can control more than the standard 4 injectors.

I guess you could call it sequential, it\'s a similar principal to the twin turbos!

[grinder]

so based on all this , could you run 850 from an FD as FC secondaries ??

or would you need a programmable ECU to run them ?

would they fit in the rails aswell ?

[chris]

one of the biggest issues is the injectors are not a straight forward swap over as FD\'s are side feed and FC\'s use top feed so the rails need modifying to suit