0202005 which is the same....
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0202005 which is the same....
I was hoping you had something to view the calibration for the gen 4.
We can live without boundary adjustment in efilive as long as we know where it is, I would think you would only need to adjust if your IPW was maxing out (SOI approaching the boundary) and or your cam IVC was was a lot later than 585ATDC.
What do you mean view the calibration??? on gen IV there is everything we need to actually calibrate this properly....
You guys need the boundary for the E40?
You can not view or adjust the boundary in efilive for e40 or e38Quote:
Originally Posted by Highlander
Yes, this is what I'm actually running.Quote:
Originally Posted by Highlander
:)
All this info is above my pay grade. Is there a magical number to adjust the setting(s) to when you know your cam intake valve is openning xx degrees earlier than the stock camshaft?
No,.. just that :)Quote:
Originally Posted by picnic_george
It would seem that with overlap people are having better luck delaying the injector as to eliminate it going out the exhaust valve if I have read that correct. This is acheived by increasing the value in B3702, correct??Quote:
Originally Posted by Gelf VXR
Quote:
Originally Posted by picnic_george
Except for LS1 it is in ms rather than degrees... requires some external math to convert between ms and degrees.Quote:
Originally Posted by Gelf VXR
I'll get a grasp around the mathematical equation eventually. I'm just trying to understand that raising the value delays the injection cycle and people have(generally) seen smoother idle and less fuel smell with overlapping cams. Due to not sucking unburned fuel out of the exhaust, even though GM designed it to spray on a closed intake valve to help atomization(which it will no longer do). I'm still doing a lot of reading and some of the numbers seem awkward to me, but I'm pretty good with numbers so I'll get it lolol
Thanks
Unless your IJC is maxed out, start to end of injection happens while that inlet is closed, and some time before it opens to allow for vaporization, with a high overlap cam I would try advance far enough so vapor rather than raw fuel can be drawn into the exhaust.
It's theoretically possible to have the injection event after EVC, it doesn't for much duration before IVC, and only when at running temperature, not a very efficient burn
What's IJC?
From what I've been reading it seems like people have been having luck delaying the injector some(til the tail end of the EVC events and not paying too much attention to the IVO events). Too early you suck fuel out the exhaust valve, too late and you can't use the exhaust to help draw the fuel in. Granted that happening eliminates the fuel hitting the closed intake valve. I guess I should have joined the discussion a few years ago lolol
Thanks
IJC ---> I think Gelf meant IDC (as in INJ DC).
My bad i meant IDC, thanks Joe.Quote:
Originally Posted by picnic_george
You have to remember the calibration is for the end of injection EOI, SOI is calculated in advance from EOI depending on pulse width, so SOI happen after EVC, you need to retard EOI well into the induction stroke. If your running closed loop idle, a poor homogenous charge surely will play havoc with O2 sensors, keep adding fuel if O2 reads lean because the unused O2 in the combustion.
I don't have a high overlap cam so I have not tried for myself so I could be wrong :)
I made a sheet that explains all the math because I had to spell it all out the long way before I understood it. What it boils down to is you need to add to the injector timing table how ever many degrees the IVO of your new cam is over/before your stock cam and play with it from there. So, stock cam opens at 16* ATDC and new cam opens at 8* BTDC then you add 24 to your injector timing table. I also noticed in my particular tune that there was no advance in Timing vs. RPM. All the other cars I found had some. So I copied and pasted to see what would happen. It seems to be working.
Can you post your sheet (or an image of it), please...Quote:
Originally Posted by PRAY
I suck at posting pics and what not on the net. Can I email it to you? It is all of the notes I have made and the math that goes with it for this subject on a word document.
Hey Joe,
Did you get my email?
I'll check my email...
Okay, I sent you what you asked for last week.
I don't see any emails that might be from you (not in my inbox nor in my junk/spam folder).
Okay, I will resend. It would have come from Ber1tuning@gmail.
Ok, I'll look out for it.
I did not see email from you... so I sent you an email using the email address you showed in post #143 above (with .com on the end of it).
ting research paper of injector timing, open inlet valve vs closed inlet valve injection
http://www.v-eight.com/multimedia/li...n%20engine.pdf
"However, one can speculate from these trends that the effects of injection timing on mixture quality are the reason for differences in CO emissions. Since the CO is formed due to a lack of oxygen present to make CO2, a better mixture quality is essential to lowering the CO emissions. From already stated reports dealing with HC formations, it was found that OVI injection timing can cause a local stratified mixture in the cylinder, which would cause more CO emissions due to locally rich regions in the cylinder. Conversely, with CVI timing, the fuel is transported completely through atomization. Thus, less fuel becomes stuck near the cylinder wall, causing a more homogeneous mixture. At low speed, gas temperatures and air velocities are lower than for the high RPM case. At low load, the gas temperatures are less hot than at high load. Therefore, changing from low load/speed to high load/speed has an effect on fuel/air mixing properties. However, it can be speculated that the differences in mixture quality between OVI and CVI timing become smaller as speed/load are increased. The high temperatures in the cylinder help the fuel on the cylinder wall vaporize, and the high velocities will help the fuel mix with the air more effectively during OVI timing. Once these conditions were combined, such as in the case of high load and high rpm, the data actually showed a small increase in CO emissions for the CVI timing case.
Injection timing also had a significant effect on hydrocarbon emissions at low engine speeds. This is illustrated in Figure 6. In all cases at 2100 RPM, negligible differences in hydrocarbon SE were observed. However, at 1500 RPM marked differences were detected. Stoichiometric conditions were affected the most by injection timing. For instance, the HC specific emissions (with φ=1) decreased approximately 30% at both load conditions. At lean conditions, the HC SE decreased 16% and 25% at loads of 200 kPa and 400 kPa, respectively. These results coincide with the findings of Arcoumanis et al [8] and Yang et al [4]. These changes occur for many of the same reasons mentioned in regards to CO emissions. The larger number of fuel droplets as well as the higher concentration of fuel near the cylinder wall from OVI timing decreases combustion quality, maximizing HC emissions. Once again, as shown in the CO data, the higher engine speed/temperatures at 2100 RPM quash all benefits inherent in CVI timing."
All the calculations around the net about the low resolution periods is INCORRECT! Lo Res periods is NOT 90 degrees.
If it's not 90 degrees, then what is it?Quote:
Originally Posted by Highlander
+1^^^
My thoughts would be a low res period of 720 degrees, hi res period of 6 degrees. Low res being the cam sensor which is a single pulse per cam revolution, Hi res from the crank reluctor which has 58 teeth, but is actually 60 minus 2 in the spacing.
Don't all gen 3 engines have a 24x reluctor though? And if not all, most for sure.
Correct. I had a blonde moment.Quote:
Originally Posted by picnic_george
That would put the hi res pulses at 15 degrees.
If the hi res pulses are 15 degrees apart, how many degrees between the lo res pulses (90 as highlander said...?)...?
low pulse is not 90 degrees apart.
Going from the waveforms in the manual, the cam sensor pulse runs on for 360 degree crank rotation, off for 360 degrees. So 360 apart. The crank uses a mix of 12 & 3 degree pulses at 15 degree intervals.
What do you think it is?Quote:
Originally Posted by Highlander
On the other forum the pulse degree angle and checked on some apparatus and confirmed it is 90 degrees, was he wrong?
http://www.hptuners.com/forum/showth...OI-fuel-timing
No... the pulse might be 90 degrees apart, i just misunderstood what it meant.. but the pulse is 65 degrees before top dead center....
So the calculations have to be made in base of that information.... it doesn't matter what they are apart.
I don't have the equipment to test, but a simple calculation yields a very similar result if you use 784 and 90 degrees or if you use 720 and 65 degrees.
If you have 65 degrees before top dead center, and you have certain amount of periods, it means 65 x Lo Res Periods... so it makes no sense for the ECU to have specified this angle in the calibration and have it use 90 degrees since they are apart.
The other problem is ... we don't exactly know when the ECU is actually asking for pulse after the boundary.... it can shoot the injector before the boundary and after if it needs to. My guess is that if conditions change after the calculation, then it does fire afterwards. If we don't know what that criteria is and how to control it, my guess is that we are still chasing our tails.
Been looking into this lately for my own car and found a couple of good threads over on hptuners forum. this post below is the standout on how it all works.
This now begs the question, when can we get the injection timing boundary value into efilive for the custom os5's. we only have the injection timing and injection timing trim, there is another single value data point for the boundary.Quote:
To put it into context, the whole thing is about vaporization of fuel in a stock setup, and about not throwing out fuel on the cammed up side.
In a stock rig, the injector sprays onto the back side of an intake valve. Both valves are in contact with the heat from the combustion chamber, but only one valve ever looks like it's been hot, right? That's largely because the intake valve is being cooled off with fuel, and nothing cools the exhaust valve directly.
In stock form, it's about turning raw gasoline (liquid) into burnable vapors (gas). Raw liquid gas doesn't burn, only the vapors do. So we use an injector at 58 psi to turn big gulps of liquid fuel into small droplets of gas. EFI and it's high pressures do this wonderfully to begin with, compared to the raindrops of fuel coming out the bottom side of a carb, right?
Then we spray this fine mist in a cone pattern onto the back side of the intake valve, and we shape the cone to hit near the edge of the valve, by the seat. This way it cools off the hot sharp edge of the valve, and as the valve opens, the air flowing in tends to shear the droplets into even smaller droplets.
Since the cool fuel hits the hot valve, it tends to vaporize and become a gas. So picture it in your head. The intake valve is closed, the motor is idling, the injector PW is maybe 2 - 4 milliseconds at idle, and the injector delay table is programmed to spray onto the valve just before it opens. This way, other cylinders going up and down don't inadvertently steal the air and fuel vapors out of this intake runner.
The injector will have a start time and an end time. The delay table back-calculates the injection timing. So let's say the intake valve is going to open at X degrees of crank rotation in the engine cycle, and the engine is idling so it only needs 3 ms of pulsewidth. The injector would END its spray pattern just before X degrees rolls around. So it would have to START it's spray pattern at 3 ms before X in order to finish by X. If the pulsewidth jumps up to say 15 ms at WOT, then the injector would finish by X still, but start at 15 ms before X.
Here's where it gets interesting. You can calculate the engine speed, the 720 degrees of crankshaft rotation (the cam runs at 1/2 the speed of the crank), and you can figure out exactly how many milliseconds (ms) of time becomes how many degrees of crankshaft rotation. That's just math. So if you're only idling, that start and end of injection time (SOIT and EOIT) will be very close to the time when the intake valve is about to open.
So picture the closed intake valve, the injector opens for a few ms before the intake valve opens, and it closes just before the intake valve opens, making sure that fuel is now vaporized, broke up into little bity pieces, and basically a gas cloud at this point. Then the intake valve opens, that gas cloud immediately gets sucked into the cylinder, and it's ready to be exploded.
Now picture a cam change. We have a cam with a lot of overlap (because it sounds cool at the local drive-in). The intake valve and exhaust valve are now open at the same time, in a way the factory never intended. The intake manifold has vacuum in it (at this point, that vacuum is coming from the other cylinders!), so the intake runner is in a state of low pressure - vacuum. The exhaust system on the other hand, has high pressure in it, from those other cylinders firing and trying to get out thru a small pipe, causing some backpressure.
Now both valves are open at the same time, so the high pressure goes towards the low pressure. That means the exhaust goes in the exhaust port backwards, goes thru the combustion chamber, and exits out the intake port. It pushes some of this nice vaporized fuel cloud backwards, up into the intake manifold. (This is called reversion or standoff in carb speak). But that doesn't last long, and then it reverses direction and the intake charge now gets sucked out the exhaust valve instead.
But our computer calculated just the right amount of fuel, no extra. So we can't afford to lose any fuel out the exhaust valve, or the cylinder runs lean. So we end up richening up idle to compensate for the lost fuel. This is why cammed up cars like to be richened up at idle and low speeds.
We could move the injection timing back some, so that we don't inject fuel into a valve that has already opened. And that might be good, if we have a longer duration cam than stock, but we don't really have any more overlap. So maybe for a mild cam, that works well.
But if we move EOIT back like that, we make it more likely that the other cylinders steal fuel from our intake port. We also still have the problem that as soon as the intake valve opens, some of that fuel is going to go right out the exhaust anyway.
So if the cam is pretty big, we go the opposite way of common sense. We inject the fuel later, onto the back side of an intake valve that's already opened. Why? Well, with longer duration, we can't start the injection any earlier, or we'll end up injecting on the previous engine cycle, where the valve is still open from the last time. So we're going to lose some of that fuel vaporization by doing this, but we are going to be able to time the injection more properly to the longer duration cam.
We're also not building up that cloud of fuel, just so it can easily get pushed back up the intake, or straight out the exhaust, as soon as the valve opens. Better that we spray it in as we go, instead of 'building it up just to get stolen' all at once.
On here, guys are trying to time the injection so that the exhaust valve has already closed. So that means a few degrees after TDC, instead of a few degrees before TDC for EOIT to happen. But what I think is being overlooked is the fact that at WOT, the injector duty cycle is supposed to be roughly 80%, right? So the injector is open 80% of the entire 720 degrees of crankshaft rotation. Which means it must START long before the intake valve opens, and end long after the exhaust valve closes.
Because of this, I theorize that it's not really about the exhaust valve open/close points, as much as it is about starting the injection at the right time (to match the new cam opening/closing points), and about not having the cloud of fuel stolen or completely evacuated out the exhaust valve.
More common thinking is that it's only about the overlap period, and losing so much fuel out the exhaust, and not so much about having fuel stolen from the intake runner by other cylinders (or pushed back up the intake by exhaust pulses during overlap).
At higher speeds, all this stuff sort of works itself out. But at lower engine speeds, the overlap may be the exact same amount of crankshaft degrees, BUT the amount of actual time it takes to pass thru those degrees (a product of RPM) is much longer. So it's sort of like trying to play ping pong in slow motion. It just don't work.
My best guess about what to do here is to experiment with EOIT by slowly adding to it, making the injector start and end it's on-time later in the engine cycle. (Unless you have a mild cam, then maybe go the other direction). I would start by adding 10 degrees of delay at a time, and monitor the results. If you are improving the situation, you'll notice that the engine is getting richer on the wideband.
This is because the correct cylinder is actually GETTING the fuel you injected for it. So an increase in a/f ratio is an indicator that you're improving your situation. Obviously, you'll end up going back to your airflow model and leaning the car out to compensate eventually.
If it liked 10, add another 10 and see what happens. It's tough to say exactly how much a motor would like, since all cam overlap periods are going to be different. But somewhere between 20 and 40 extra degrees sounds about right.
The LS1 PCM doesn't go by actual crankshaft degrees in their delay table though. They go by reference periods. Each reference period is 90 degrees. So if you want to add in 10 degrees, you would add .11 reference periods. Also noteworthy, some clever fellow on here decided to take an engine on the stand, and test it to see where the 720 degree cycle actually starts at, and found that it started at -784 (if I remember correctly). That's just about where the cam sensor is relative to actual TDC on #1, and about actually sensing the crank magnet go by BEFORE the cycle starts, so the PCM has time to get it's act together by the time the cycle actually starts.
That's unimportant if you're just going to add 10 degrees at a time until the motor doesn't reward you any further. But it is important, if you have drawn up a 4 cycle chart on paper, and are trying to actually calculate when the injection timing is going to end, compared to when your cam valve open/close points happen.
And just when you think you've got it all mastered... "did you degree the cam in, and has the chain stretched any since?". heheh
It's not rocket science. Just add a little delay in at a time to the normal table, and probably leave everything else alone. I am a bit less informed of exactly how the makeup thing works, but I'm sure it's about the same way. I believe makeup is made up of things like acceleration enrichment and other last-minute changes to fueling, while normal is the typical fuel injection cycle.
Thanks for the quote.
It seems that SOIT/EOIT is important at low engine speed, and that it becomes irrelevant at higher speeds
(for example, 80% INJDC spans a 576* out of the 720* cycle, and at 6000 RPM 720* is only 20 ms).