Ken, not trying to say you wasted money, but I did read some of what he had on his site. I would like a further explanation if he would, as it seems almost like overkill. Some hondas have saturated injectors stock, pretty much all of them from 92 and up, except for the ludes. In 88 - 91 they ran peak/hold, and just had an injector resistor. We just changed over a stock Integra with saturated 240 injectors to peak/hold 550s. No problems with the ecu or injectors. Unless the ecu has some sort of voltage drop circuitry for the peak/hold styles, which I don't see why it would, as it was designed with saturated in mind, it won't last according to LJ. Hmm.. just trying to understand this some more. Please post any info you find out! I thought about trying some big injectors in my car with a resistor to drop the voltage down, like a honda would. I have a set of 83s laying around from a mustang that is in the shop right now.

 

The $EE PCM simply grounds one side of the injector to open it. The other side of the injector is connected to battery voltage via the ignition switch (12V supplied to injectors only when the ignition is on). High impedance injectors can handle full voltage across them without burning out the wire coil inside, and the drive transistor in the PCM can handle the ~1 amp of current needed to open the injector, and hold it injector open.

What if you try to drive low impedance injectors with the PCM without changing anything? When the PCM grounds the low-Z injector to open it, the current through the injector wire coil and the PCM drive transistor be be somewhere in the neighborhood of 3 to 6 amps. This much current, if it stays on for more than a few milliseconds, will overheat the injector wire coil and the PCM drive transistor, causing one or both of these components to fry (sooner or later). You might get away with it for idling and cruising, where the pulsewidths are just a few milliseconds long, but you'll let the smoke out at WOT when the pulsewidths go into the upper teens and the duty cycle gets to 80%. Electronic stuff does not work after you let the smoke out.

What about just putting a 10 ohm resistor in series with the low impedance injector, which would limit the current to 1 amp, just like the stock high-Z injectors? Low-Z injectors are *designed* to be yanked open with about 4 amps of current. The pintle (or disk, or what-have-you) gets heavier as the rated flow gets bigger, so the wire coil inside the injector has to yank harder to open it quickly. More current = harder yanking! A big, low-Z injector might not even open, or would open sluggishly and erratically at best, if it only saw 1 amp.

So low-Z injectors are peak and hold. The peak current *needs* to be on the order of 4 amps to yank those suckers open. the hold current *needs* to be around 1 amp to prevent the injector coil wiring from overheating and failing.

This is exactly what the Acceleronics Impedance Converter does. It intecepts the 8 injector signals from the PCM and converts each one to peak and hold.

My $.02 on this is; if you need to get that last 10hp out of your engine, you *should* spend 10 times the money (as in thousands instead of hundreds) for a wide band FAST system. If you're budget minded, the Converter at $375 is a very effective solution. I've had no trouble tuning my blown car to run on 75's, and I expect no trouble when I drop in the 92's to support the new ys-trim.

My schedule doesn't allow me to hang out on all the web boards that are talking about the box (I've sold many to Stangers), so please email me directly if you have more questions.


LJ
http://para.noid.org/~lj
www.acceleronics.com

 

Thanks very much for the info LJ!