Talk to me about stand off injectors...

[laine_16v]

Hi,

I've been told these are good to use if possible. Currently i use Jenvey DCOE 45mm bodies, short manifold and 90mm air horns.

The current injectors are Bosch 289cc Hi Impedance jobbies that are located half way in the THrottle bodies themselves (pretty standard).

My question is, im obviously going to need another fuel rail, set of injectors e.t.c

Does VEMS work well with stand off injectors, and they blended / swtiched by RPM / load?

Can i keep my current injectors primary and use a set of other inecjotrs ive got as the standoffs (these inejcotrs are low impedane 200cc ones, can i use ballast resistors in stand off setups?)

Any help appreciated. Heard they can net 10-20% power gains alone at 5000rpm+

[GintsK]

Last weeks I was forced to configure/tune second fuel rail on one of my customer cars.
Reason: main injectors in throttle bodies spraying "uphill". Fuel at idle and partial load flowed backwards and accumulates in the intake. Race car has very poor driveability at low and partial loads.

Small set should work until intake air flows really fast. But VEMS do not allow such strategy for staging. Second set can be started from TPS level or MAP level. Both unusable for describing air flow.
I decided to use two separate switchable configs actuated by misc1 only when Rpm >5000 and throttle >53%. and back when Rpm <4700  and TPS <47% (every config own misc1 setting for some hysteresis)

Then problem was uncertain state of injector outputs from currently unused set. When config switched over, program have no care about outputs state. I solved this issue by misc2 in currently used config to switch all four injectors from other set off.

Now car drives much much better. Only issue is small jerk when injectors swithces over.

Gints