Hello,
I think you need a little help to learn to understand the ECM and it's communication with the VP.
"My question is, from a performance standpoint, what is the advantage of a modified ECM over fueling and timing boxes?"
For me performance is not only the HP readings that a dyno can give, a little more is involved.
The advantage of the ECM over a fuelling box is, firstly the driveability, second the EGT's.
Let me explain better.
Just as an example, all you guys with an AT,
when it shifts into OD, ever noticed how low the boost drops?! It takes more and more effort on the right foot to get the boost climb again.
With the ECM modification this is no longer. When it shifts into OD you can back out of the throttle, because now, then more load the engine has then stronger it pulls.
Think about it!
You're climbing a grade with a large trailer and want to pass the Phurd... . The OD pulls stronger than it ever did! Ok, that's an driveabilty example.
Some other could be how fast can the boost raise, RPM limits, or timing, but I don't want to bore you with too much stuff.
Now let's get more technical.
Timing! It seems to me that most people think about timing like a single point in time and space. WRONG!
Timing for the injection is made out of TWO points. The beginning of the injector spraying fuel and it's END!
What happens when you add a fuelling box?
They keep the fuel flow valve of the VP open for a longer time. They allow more fuel to flow. Yeah, more fuel but also for a LONGER time. At relative low RPM's that's not a big deal. At high RPM's the VP has less time to inject fuel because the speed of the pistons is higher. The box allows fuel flow for a longer time, it injects fuel for too long, too late. Away the EGT's go... .
You guys with the boxes, ever noticed that EGT's climb rapidly at higher RPM's?
WHY?
Got it? Did I make this point clear?
Maybe I should have started from the beginning, not from the end. Let's get to the beginning of the timing story.
Timing! The ECM tells the VP for Each single injection pulse, when to start, to end, and how much fuel. It tells that to the VP right NOW. It doesn't tells the VP sometimes before the pulse has to happen. The ECM says act, the VP reacts instantanously.
This brings me to the "Timing boxes".
I would like to know, how such an box can Anticipate an event that's happening in the same moment the signal is send/recived???
Would be like knowing the future!
Point is, it CAN'T!
Also, keep in mind, it isn't said that the impulse that follows, is the same like the previous one.
MAY be that those boxes are so smart and FAST that they can advance those signals.
Sure enough they can't advance it a significant amount. They don't have the time to do so! The piston is moving... .
Not even worth to call it timing advance.
I've seen two different kind of those boxes, none of them did a dime to timing. NO, I will NOT make names!
When we speak about the so called "Timing Boxes", you shold keep in mind that the ECM doesn't, DOES NOT!!! have a fixed timing.
A large part of the ECM works on timing.
I know 36 different fields in the ECM that work on timing. Different RPM/boost/Engine temperature combinations have different timings. In such an scenario, how can you simply add some degree to the timing? At the very best, this would be harmfull to our engines.
I still have not answered the question.
All this stuff to lay down a baseline from where to start my BOMBing purposes.
All the above mentioned rules apply obviously to the ECM too!
The highest POSSIBLE timing ( start and end) for the ECM isn't as powerfull as one of the GOOD boxes one can buy.
Hey, have I said isn't as... . ?!?
In which conditions? What kinda mods?
Which rules?
Rules are simple; EGT's!
To keep the EGT's under controll one has to stuff the added fuel within two precise moments. The begining and the end of the injection pulse! PERIOD!
How can this be archieved?
I have four possibel ways in mind.
First is the ECM, done.
Second, HUGH injectors, since they can flow more fuel in the same amount of time. They are being build for me.
Third, to a certain degree ( depends on the mods) a reasonable fuelling box. I'm building a fully customable box to add to the ECM. Nearly done. Time a week or two.
Fourth, a bigger VP. This one is.....
I don't want to do what all the others can do. I want to do it better! I want more power. At lower EGT's, with less expenses in mods in order to controll EGT's.
I want to raise the bar!
'Nough said?
The last point that got my interest is the warranty question.
I don't think it's important HOW you void the warranty! If I kill someone it's not important if it was done with a gun or a knife. He's dead...
#ad
Oh yeah, last thing then I promise that I'll let you go!
#ad
The fuelling boxes don't override the ECM's signal(s). They add their signal(s) to the ECM's one(s). And the VP "CPU" has no limits, it's a simple executor.
Sorry for being so long winded!
Thanks for your attention.
Marco.
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