"De-engineering" a project--injector choices.

[ImprezaRSC]

I'm thrown for a loop on what to do for a replacement of these big, weird fuel injectors. I'd post pics but they're packed under these big fuel rails.

I have 900cc+ injectors that are low impedance top feeds. I need smaller flowing high impedance injectors of the same body type. The existing injectors were controlled by a Link ECU that is no longer in the vehicle. Luckily, I can revert to a stock ECU. The problem remains that these injectors are too damn big for the stock ECU. They also require a resistor box.

The problem I'm stuck with has three parts on the car

--custom fuel rails for these injectors
--this special JDM intake manifold that only works on phase 1 heads.
--this current manifold and fuel rail set being fitted for these "different" injectors that sit down into the manifold pocket.
--The manifold was also NOT machined to fit.

I've noodled with top feeds, but these injector bodies are different. It's not a side feed style of injector, but has a fat body like the pic below. I can't use the JDM grey tops OR the WRX style Denso/Bosch injectors. These injectors look like Bosch Ford units.



Thoughts? I think I can get high impedance injectors that fit these rails and I'm good to go. I'll be piggybacking a set of secondaries with a PerfectPower SMT6.

[93forestpearl]

Outfront Motorsports makes a nice topfeed injector kit that allows you to run Bosch style injectors on the EJ25D intake manifold. I'll be going to this setup when I run out of room with my 900cc sidefeeds.




One thing to keep in mind is that large, low impedance injectors should be ran in a peak-and-hold format. When run with a resistor box in a saturated method, the injectors are slow to open and you end up wasting a lot of your fuel capability. On small injectors, like what comes from the factory on Hondas, this is a non-issue. Step the size up significantly and you start to see problems.


FJO Racing Products makes a nice little 4 channel peak-and-hold driver to run low impedance injectors instead of a crude resistor box.

[ImprezaRSC]

I'd like to get away from these low impedance injectors entirely. I'd prefer using those new 1,000cc Bosch units but it's a fitment issue. Is there a high impedance replacement that readily fits? It's a special JDM manifold that I'm working with.

[ImprezaRSC]

Solved! I found a set of high impedance 525s that fit. These are Delphi/Rochester style injectors I'm replacing. Figuring out what these were was the hard part. I had never seen these before.



From here:

http://www.fiveomotorsport.com/Injector_SetsMODS.asp