nuro

is there a difference in ease and options, tuning wise, between peak and hold+resistor pack vs. high impedance injectors (given use with the AEM EMS)?

Joseph Davis

A resistor pack has no place inbetween your ECU and injectors.

Run the correct resistance injectors - most standalones can run either high or low impedance injectors, the EMS is probably the same.

racerxadam

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">A resistor pack has no place inbetween your ECU and injectors.</TD></TR></TABLE>

In this case how do you limit current flow through the injector driver so as not to burn them up?

nuro

the EMS can only use high impedance injectors...

Joseph Davis

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by racerxadam &raquo;</TD></TR><TR><TD CLASS="quote">

In this case how do you limit current flow through the injector driver so as not to burn them up?</TD></TR></TABLE>

How about you run the correct impedance injector for your ECU?

double0Si

what if you need a larger injector than is made in the impedence of the stock injectors??

And why not use a resistor box, like Honda did for a few years....

racerxadam

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">How about you run the correct impedance injector for your ECU?</TD></TR></TABLE>

How about you lose the attitude, I knew I was going to get a smart *** answer so I purposely wrote the question in the way as to least provoke you. It was a pretty simple question and its obvious that it was well within your superior intellect to answer. I thought that perhaps you had some super secret squirrel internal ECU mod that you were referring to cause you are the ECU god or whatever.

m R g S r

Why does it matter if there is a resistor box?!? I've seen them work fine time and time again.

nuro

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by m R g S r &raquo;</TD></TR><TR><TD CLASS="quote">Why does it matter if there is a resistor box?!? I've seen them work fine time and time again.</TD></TR></TABLE>

thats what im saying too, but i dont know nearly enough about how these work to pass my own judgment on this subject

Joseph Davis

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by racerxadam &raquo;</TD></TR><TR><TD CLASS="quote">

How about you lose the attitude, I knew I was going to get a smart *** answer </TD></TR></TABLE>

How about I keep my attitude, and you come to accept the fact that it's not the attitude you ASSume I have. Ask anybody who's ever met me IRL - Joey is not like the other kids in the trailerpark.

I get tired of explaining the same thing a lot, sorry if I came off the entirely wrong way. It was not intended to be insulting, I apologise if I communicated poorly.

At the time the Honda ECUs started using the resistor box trick, high impedance/low current Darlingtons (the sort of transistor an injector driver is) were a lot cheaper than the low impedance/high current Darlingtons. Also, oddly enough, low impedance injectors were real cheap but the high impedance injectors were not. Resistors have always been cheap. Honda cut a corner.

Here's how to test my statement, you will require: dual trace oscilloscope, spare knock sensor, ghettofabulous injector test bench, timer circuit w/ darlington to pulse your test injector (you can rig this to be an on-car setup if you're slick, use the aforementioned ECU to pulse the injector). Monitor voltage drop across the injector with one o-scope input and the KS with the other input. In a correctly matched setup, you will note that the KS registers the injector clicking open in sequence with the injector being pulsed. In an incorrectly matched sequence there is lag, and muddy response. Play around with the injector at different pulsewidths, it gets.... disheartening.

There is a reason why a number of standalones have a rep for being able to make more power than the Honda ECU, and it's not the fault of the Honda ECU. It's the fault of an incorrect premise.

And, morncoil, VTEC is pink for good reason... if you've ever wired a VTEC solenoid with pink wire you'd notice the 20 extra mad JDM whp... stunna.


Modified by J. Davis at 2:26 PM 4/22/2004

boosted15

the ecu has nothing to do with the resistor box. all honda ecu's put out the same voltage no matter what. if you use low impedence injectors ,then you use the resistor box. if you use high impedence injectors theres no need for one. the resistor box will limit voltage so you don't burn out the peak and hold injectors.

nuro

so even after that long and interesting explanation - i still don't see the clear answer: is a resistor box going to limit the tuning capabilities of the EMS or not?

JDogg

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nuro &raquo;</TD></TR><TR><TD CLASS="quote">so even after that long and interesting explanation - i still don't see the clear answer: is a resistor box going to limit the tuning capabilities of the EMS or not?</TD></TR></TABLE>

not it wont.. there are countless guys running 1000-1600cc injectors with resistor boxes on supras with no problems. we had 880cc precision injectors with a resistor box running fine.

racerxadam

just because a solution works doesn't mean that it is correct. The lines you need to be concerned with in his post are:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">Monitor voltage drop across the injector with one o-scope input and the KS with the other input. In a correctly matched setup, you will note that the KS registers the injector clicking open in sequence with the injector being pulsed. In an incorrectly matched sequence there is lag, and muddy response. Play around with the injector at different pulsewidths, it gets.... disheartening.
</TD></TR></TABLE>

Joseph Davis

Stunna JDogg told me once in PM that some of the EMS guys were getting stock GSR engines to hold 500 whp for short durations, until the power levels shitcanned the engine due to the stresses involved. The point of that was to illustrate how tuning would allow you to tap those power figures without blowing up the engine on the way there. Like with many things associated with the hardware aspects of good tuning and a good engine management system, you need high resolution on your sensor inputs and actuator outputs, you need fast + responsive processors that are coded well so they don't lag, and you need your sensor and actuator systems to be on a par with the computer that runs the whole gig.

Running an impedance matched Darlington and injector combo is another level of this finesse. Those Stoopras running the 1600cc injectors? How was the idle quality? You think more precise injector control would help that out some, or what?
I can assure you that the setups that would idle those injectors do not include the use of resistor boxes, and muddy idles and poor transient injector response times are not what i call "running fine," Jason.

I have the .pdf file containing the honda injector driver spec sheet, I'm happy to email it to you and then allow you a couple years of electronics classes so you can learn how to understand it, and we can pick this argument back up then

This is another what you should do vs what works scenario. It's exactly like the AFC hack in my mind... you should do something else, but plenty of people have reliable AFC hack setups running around.

Joseph Davis

http://www.sanken-ele.co.jp/en...e.pdf

Importracer_001

Is it possible to run saturated injectors in a 1990 HOnda crx with a resistor box?
I already have these injectors but didn't install them yet so please help me out on this

JDogg

no, you would have to take the resistor out ot make the saturated injectors work,