Gernby

I think I understand the differences in how the eManage controls fuel as compared to the VAFC, but I have no idea how it controls ignition timing. What does it wire up to? Does it alter any OEM sensors to trick the ECU, or does it actually wire straight into the coils?

While I'm at it, let me make sure I understand about the fuel control. From what I've read, it seems that it alters MAP for REMOVING fuel, just like the VAFC, but it can also be wired into the fuel injectors directly to extend the pulse width if it needs to ADD fuel. Correct? If so, what is it about the eManage that allows larger injectors? Why wouldn't a VAFC be as effective for larger injectors, assuming the larger injectors provide enough fuel using the OEM injection pulse width?

bigpurp

Curious on this end as well. Anyone??

SpEeDxXxRaCeR

I would think the VAFC just lacks a lot of options, thus costing 2x less then the greddy emanage. I have the greddy and the profec e01. The greddy allows u to input your injector size (or test), therefore answers that question I think. I'm new to this part of the car area, therefore I'm curious as well.

-Trung

Flite

I'm bumping this up hoping that someone will chime in. I'm very curious as well.

Fyrestrike

My E-manage is on the way so I'm latching on too. Hopefully Westmaster sees this.

AusS2000

Looking for me! <in my best superhero voice>

Gernby is pretty much spot on with the fuel side. It has 2D maps for MAP-based fuel control so it's much like the V-AFC except instead of two 16 point graphs it has a 16 by 16 map of RPM vs. throttle position.

The injector correction is just a global modifier of the MAP signal. Suppose you have 440cc injectors and stock is 380. You enter these values in the the fields and get a correction of 0.86. That would be the same as entering -14 in the V-AFC maps or in all the E-manage AAV fields.

But then you actually tune the AAV map. If later you decide to change injectors you only have to enter the new injector size in the injector correction field and no retuning is necessary (well, I'd still do a dyno run as the relationship between MAP and fuel won't be exactly linear).

As mentioned the E-manage can also directly increase the injector pulse phase by holding the injector signal high longer than the stock ECU. This is another 2D map with pressure (or MAP signal) and RPM as the axes.

With regards to ignition, the E-manage intercepts all four coil wires at the ECU. I assume it provides it's own signal based on the injector signals and they are either delayed or advanced (in which case I assume they are one phase behind the ECU signal).

The E-manage does a couple of other things as well such as clamp the MAP signal (for us FI guys), has an anti-stall feature, and can drive additional injectors.

ItalianBucwheat

I thought that I read in a Jenner post that larger injectors really won't work with the vfac....well, it will work
but your idle will really suck! Is this Correct?

Slows2k

Pretty much correct. I beleive Jenner was trying to use 780cc injectors, which is above the E-manage's correction factor of 150% over stock.

Gernby

I can see how the eManage could easily retard timing, just by intercepting the ignition pulse, then waiting X msec to send its own ignition pulse. However, that method can't be used to advance timing, since it would have to guess when the next ignition pulse is going to occur, then send its own ignition pulse X msec before. If the timing curve was very predictable (ie. linear and repeatable), then it could interpolate, but the ECU uses a lot more factors in determining timing than the eManage sees.

chrissa

[QUOTE]Originally posted by gernby
I can see how the eManage could easily retard timing, just by intercepting the ignition pulse, then waiting X msec to send its own ignition pulse.