Thanks Howard.
My issue seems to be a little more serious than just running too rich. I'm having a non starting issue now and when it does kinda kick over a few times, it sounds horrible and it doesn't seem to be firing on the rear rotor. I'm wondering if the resistors I was using stressed the injector drivers enough that this caused them to give up the ghost. I'm still troubleshooting so...

 

PM me w as much detail as possible and maybe i can help you Railgun.

hc

 

So I wired up my four 1000cc secondaries to the FJO by pairing up the inputs (red with orange goes to one secondary wire(ecu side) and green with yellow goes to the other secondary wire(ecu side). Can anyone confirm what I should set the injector size to in the PFC? I'm thinking 1,000 for each since the FJO replicates what it sees on each input...?

 

Found my issue.

Seems that when I was doing the wiring, my first attempt was to remove the pin from the clip at the ECU to make the rewire easier. Well, I wasn't able to remove it as easily as I should have been able to and I didn't want to force it, so I left it in and did it attached. It seems that in process, I had, for lack of a better term, damaged the pin enough to cause it to not make contact with the pin on the ECU. I'm guessing when I was trying to push it through, I opened the space up enough to cause this condition. I did look at it before I put everything together and it looked fine, but didn't think to revisit that when I encountered these issues.

Sure enough, everything was fine to the clip, but when I checked continuity at the back side of the pin in the ECU, nothing unless I wiggled the wire. So I'll button her up here in a few and report back with any issues I have with settings, though at this point, I think I'll be good.

Thanks for the help in the meantime, Howard.

 

If your doing what I'm doing, where two 1,000 cc injectors are controlled by one PFC injector signal, then specify 2,000cc on the secondary injector listing.

My setup, 2 550cc primaries, 4 1,000cc secondaries (2 to each rotor with a GZ LIM), zero lag all around, 40% transition with 0.1ms sec. transition (still hashing out that number, but 0.1ms is working pretty good so far), still working on throttle tip in though.

 

Thanks Howard for the tip, I currently having this tip in problem.

 

so if i install this would the tuner need to know more about it to tune it properly or would it not matter if the tuner understood what it does?

basically with this box would the way you tune the pfc change at all, other then needing less fuel?

kevin.

 

nice breakdown on the injector types and the workings and ramifications of each. i guess i understood most of it before reading this, because i was dead set on not mixing injector types, but you filled in a few gaps.

 

Well guys, I am selling my FJO box. I never even finished installing it. I ended up replacing my engine harness, which was cooked, with one from an 87 which already has built in resistors for low impedence injectors.

$150 shipped. I paid $200 brand new from horsepower freaks. PM me.

 

Just to rekindle the discussion, after developing our dynamic flow injector bench, we have discovered a couple interesting bits of information. First off, peak and hold injectors tend to have a slight "bump" in the flow curve when switching from peak current to hold, and thus flow goes nonlinear in this range... Second, as the hold current increases, the injectors tend to go nonlinear sooner at the upper end of the range... It seems the more we get into the injectors, the more crucial data we are finding, it is very exciting!

 

FYI my injector box is sold.

 

Can you be a little more specific? What do you mean exactly by bump? I'd figure once the injector is open, it's going to flow what it can, or is there a small decrease in flow once it hits hold current?

Definitely interesting.

 

check out the data sheet for the LM1949 (main driver chip used by FJO):

http://www.national.com/ds/LM/LM1949.pdf

some good info with explanations

 

Wow...I don't have a head for that anymore. That'll be some bedtime reading for sure. Nice find.

 

Most injectors aren't nearly as stable as we expect them to be in terms of flow.. We got our hands on a "matched within 2% set" from a well known supplier and found variances up to 10% dynamically.. and don't even get me started on the bosch 1600's...

Yes, an actual bump in fuel flow. It is really a pretty minor variance, but when we run the same injector saturated, there is no bump there...

I'll try to see if I can get a graph of a good example of this.

 

you mean like this?

 

No, that is just showing the log of the channels the ecu is seeing at that point in time. There could be any number of reasons why there is a dip in the secondary output signal, but no way to tell from the data in the log there.

I'll try to make this more clear.

In the above case, you are seeing the signal that the ecu is sending to the injectors based off of all the incoming signals, fuel map, and compensations. So it tells the injector to run at a specific pulsewidth to properly fuel the motor for those specific conditions. I am describing the actual amount of fuel flow coming out of that injector at all possible pulsewidths. Here's an example: say based off all current conditions, the ecu tells a peak and hold injector to run at 2.2 msec, where it is still running at peak current. Then atmospheric conditions change slightly requiring more fuel. The ecu then tells the injector to run at 2.4 msec where it is transitioning into hold and a bump in fuel flow exists there for this particular injector. The motor would be fueled a slightly different amount than it thinks it is. Don't get too alarmed, with all the injectors we have tested we have never seen any drastic changes in flow at this transition, but it is just interesting to know that that exists there.

Also, I reread my post above and it made it seem like I was trying to say the Bosch 1600's vary quite a bit from one another. That's not really the case, I was more trying to further make my point that injectors don't necessarily flow what we think they do. The 1600's have very erratic flow throughout their range and especially huge peaks and dips at low pulsewidths.

 

^Now I finally understand it.

Actually the dip on the graph above was cause by pri to prisec turbo transition.

 

With regard to installation, where did you guys get the box's main power from? The main power wire that comes out of the box is pretty thick, which makes me little concerned about the current draw . Is tapping into any switched 12V ok, did you guys wire it to a fuse box somewhere, or straight to the battery with a relay?

- Andy

 

Yes, I would just connect it to an ignition controlled power source.

 

Ok, I wasn't questioning that . I was questioning whether the thin wiring normally used in the in the engine harness was acceptable to tap into due to it's narrow gauge. I'm concerned that the narrow gauge of the engine harness wire might not be able to handle the current draw of the FJO box. On the other hand, one of you guys might come back and tell me I'm wrong because I have no idea how much current the box will really pull, so that's why I was asking.

I only have two low-impedance resistors. To be honest, I don't remember the impedance on them, but let's say it was 1.5ohms. Since V=IR, I=V/R, so I=14/1.5=9.3amps. I've got two of those, but presumably they aren't injecting at the same time. I don't know if they overlap that much, but I'm guessing they might, so call it a worst case of 18 amps or so. That's over the limit for 16 gauge wire. On top of that, any engine harness power wire that we could tap into has current flowing through it to something else too. So we need at least 14 gauge wire or thicker.

Like I said though, I'm guessing about a lot of these numbers. I also don't know what gauge the engine harness wire is, though I'm still searching for that. I was hoping someone else had already run through all of these numbers and could just tell me the answer.

- Andy

 

I have a Haltech E8 running stock 1988 Turbo 550cc injectors and ford 1600cc. one set is low impedence and one set is high impedence.

I called haltech usa and they said that it would not matter. Just set the haltech to 3 amp peak .8 amp hold.

Obviously I don't know enough about this subject but on the e6k I had no problems with staging. On the e8 I have been stuggling for a year on the staging. (Could be my limited tuning experience) Maybe it really has something to do with unmatched pairs.

Is there a need to run this FJO injector driver or should the haltech e8 driver ciruit provide adequate performance. If not whats the point of a fuel management system.

This injector driver should be an upgrade to stock components only?

Any input

 

There is no need for you to get an FJO box as the e8 is already controlling the injectors. If you have it set to 3 amp peak and .8 hold, you are already running the injectors peak and hold. I'm not completely certain on how the haltech's run both saturated and peak and hold injectors simultaneously though... I've heard there's supposedly some kind of "smart" driver that delivers proper driver settings, so if somebody who knows could chime in and correct and/or inform me that would be great.

 

FJO is now shipping to dealers an uprated Peak and Hold convertor....

it is 4 channel, 60% the size of the original unit, wires more simply and is
approx 25% cheaper at a retail of $150

model # KID0404

available NOW.

if you are still running resistors i suggest you re-read my first post in this thread. it has been over a year since i made the switch and i must confess i have almost forgotten it is on my car. i do like my linear fuel map as well as my secondaries are having to run less duty cycle because they now are properly controlled.

hc

 

From a very credible race car electronics engineer:

" I had an FJO box fail where an injector driver stuck wide open and hydro-locked the motor. So I switched to the AEM unit.

Not trying to bag on the FJO unit or promote the AEM, just relaying my experiences. And when an injector driver actually breaks a motor, you get really gunshy."

I had Injector Dynamics (2a+RoN) send me data for my primary and secondary injectors. Everything he said above is dead on. Based on the data they provided I shifted my pri/sec injector transition upward a bit to keep the secondary injector turn on MS above the operating range where they are inconsistent.