mxguy1286

iTrader: (11)

So I have been trying to find a neat way of going about running a secondary set of injectors with my stock ecu. What I need to know is will the bcs circuit handle the load of 4 injectors?

A little back round-
The car already made over 700 on pump and meth but I am getting tired of the unreliability of meth injection. E85 is not really local and not something I can run on the regular. I do the majority of my driving on pump gas and on pump gas at 29 psi the car made 618. Now I know most people run e85 with a limp map on pump but that is just not the case for me. It would be the other way around, 93 95% of the time and racing time e85. So running around on 1600+ cc injectors im just not willing to deal with. And 700+ for i.d.2000 ect im just not trying to spend right now

Heres my idea-
Use the secondary maps as a e85 map with using bcs to activate the secondary injectors. They will obviously be fired batch fired this way but above say 5500rpm it will not be a issue. Injectors are used in duty cycle anyway so wouldnt I "in theory" be able to just put in a duty cycle every 250 rpm or so to 9k and have it work? So I would have 1000cc injectors as my main injectors and pick up some cheap 880s to use as secondary injectors and have a fuel system at the flick of a switch that will support e85 but yet still run and idle great on both e85 and pump fuel as I need it.

Any input would be great!
Thanks

Raptord

iTrader: (10)

I'm no expert but it sounds like something like that would be pretty complicated and about as risky as meth injection. Wouldn't 1600cc injectors be enough?

mxguy1286

iTrader: (11)

1600s max out at about 700 and run like dookie on pump gas. Aem and lots of other ecu's use secondary injection. Its not risky at all and far safer then meth when it works right. I just dont know if the ecu will handle the load from 4 injectors on that circuit and if it will operate properly.

JohnBradley

iTrader: (30)

If you ran them to a resistor box I wouldnt see a problem. Not sure on the actual draw to the system through that set up but I doubt it would matter. Interesting idea.

Aaron

Dynotech Tuning

iTrader: (12)

+1 I wonder if we can use AFR monitoring as a closed loop correction of sorts for the WGDC?


I thought about adding a sinlge injector and have it controlled in this manner for a meth injection system ages ago but kinda...forgot about the idea over time lol.


-Jamie

Go_Lancer_Go

iTrader: (13)

neat idea...

Dynotech Tuning

iTrader: (12)

Well, we know that the BCS output can handle input resistance pretty well in the 20-40ohm area. I'm sure we can configure the injectors to stay in that range. Maybe just a single ID2000 since it will be batch fire anyways?

-Jamie

mxguy1286

iTrader: (11)

I just dont want to burn out the driver in the ecu. I know that with the dsm ecu if you use a solenoid with too much resistance it will burn out the driver.

I am sure one injector would be fine but I want to use 4 and use it as a e85 solution ya know?

Dynotech Tuning

iTrader: (12)

FWIW, I can get 2150's to run just fine on pump gas and E-85 so its not like you are limited here.

-Jamie

Dynotech Tuning

iTrader: (12)

Too 'low' of a resistance will burn it out. Running 4 high impedance injectors in parallel will be about 3.5ohms total. Putting a 25ohm/10-watt resistor in series with the +12v power leads should let the ECU see around 28ohms, which should be fine for that output circuit.

-Jamie

mxguy1286

iTrader: (11)

A Low Impedance will draw 2-3ohm with a resistor pack. So at 4 injectors that would be 12ohms correct ir no? Maybe add in a 15ohm resistor if get it up on pay with what the ecu wants to see and maybe this idea will work?

Dynotech Tuning

iTrader: (12)

Generally, injectors are wired in parallel which lowers the total resistance. I'm not sure how they respond in series. The problem is the whole peak n' hold vs saturated circuitry. I have no idea what kind of circuitry the BCS circuit is. I would do some good reading on how iujector drivers work and how the BCS signal will mimic the same thing.

This might have some info? I didnt read it yet lol.

http://www.dynamicefi.com/InjectorDriving.php

ezz-e

iTrader: (5)

Hi guys, i was just speaking to Jamie At Dynotech about this and im currently going to try to accomplish this on the stock ecu, I dont believe using the BCS output is ideal in this application, once reason i believe is because i would love to use map switching with this and in turn have a higher boost level control with the BCS. Now i know we have some open out puts that could be used like the evap solenoid,FPS, or EGR. I Have seen the dsmlink community has been using these out puts to control them with there newest version. what do you all think about doing it that way.

Dynotech Tuning

iTrader: (12)

My concern is the duty cycle. Injector duty cycle is determined by the rpm. I don't think the duty cycle is determined that way on the EGR and BCS circuits is it? I recall hearing that the BCS was determined by a constant 31hz or something like that. MrFred may know since he did the extensive BCS testing a while back.

-Jamie

ezz-e

iTrader: (5)

From my learning experience in the automotive industry the EGR opens based of a load,speed and tps input in the ecu