Moderately built LT1 / bored .030" over w/ ported heads and intake, moderate cam (CC 467) and 1 5/8 tube headers. Been tuning with the factory 24 lb injectors since finishing the rebuild, and have good confidence my VE tables are rock solid - at least in "normal" driving ranges (all load ranges up to about 3200 rpm). Runs great in SD mode, makes incredible power up to fuel cutoff @ 6800 rpm but hard to tune there because the rear tires aren't big enough or roads long enough.

So having a long weekend to tinker with it, I thought I'd try installing the no name brand, auction site injectors I bought when I started the build. The specs provided claim these are 36lb/hr / 380cc/m "skinny" bosch gen 3 clones. The auction shows Bosch 0280155737 as an equivalent part #. I'm starting to think I might have wasted $90 (I know, why go cheap here). After four months of tuning this isn't the only thing I've found I shouldn't have pinched pennies on, but a poor man has to try...

Initial start I used 36.0 lb/hr for the injector constant, and an extrapolated offset / voltage table that the seller provided. It did start and run, but with newly installed (dry) injectors and the fuel rails not completely purged of air it wouldn't last long. Subsequent start attempts seemed to flood instantly. Zeroing the injector offset adder table and cutting all the tables with "* prime pulse width vs coolant temp" (adder) tables by half made no difference. Still would only start after opening throttle to clear the flood.

Next steps were to increase the injector constant by 1lb / hr, followed by cutting the injector offset vs voltage table by 25%. Twelve or thirteen flash cycles of the E side later I'm at offsets lower than the stock Rochester specs and 42lb / hr IFC.

Oddly, when warming up at idle with commanded AFR of 14.0:1 the narrowbands are indicating a lean condition of ~130mv. Then closed loop / BLMs turn on and it immediately turns pig rich (~850mv average on the narrowbands over a short drive).

This is my first injector swap, so I'm sort of grasping at the idea I must have forgotten something obvious.

Any thoughts or ideas appreciated, including recommendations for a quality set of 32-36 pound 3 bar injectors with a known good datasheet that I won't have to sell a kidney to own. I would especially like to make these triple-C injectors function acceptably for the time being, but at this point the money lost on the junk injectors is somewhat irrelevant. I've built the valvetrain and reciprocating assembly to survive 7000 rpm. That, in addition to the cam, port work and exhaust it should be able to touch on 460-500 crank hp which is (according to what I've read) well beyond the flow capability of the 24lb factory injectors north of 6000 rpm.