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Thread: Injector Timing? Reference Periods? refereencing what?

  1. #561
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    Boundary fixed point in ground

    My hypothesis is that the boundary angle is an ABSOLUTE end/start of injections and the normal / makeup are able to be DYNAMICALLY be sized based on injector duty cycle.

    Let me give some examples with varying injection pulse lengths.

    Standard conditions: boundary 520, normal 110, makeup 30, rpm 0

    Injector pulse of:
    1)100 deg
    2)300 deg
    3)500 deg

    SOIT using our typical calculations:
    1) 380 deg (open intake valve, closed exhaust)
    2) 80 deg (injecting on closed intake valve)
    3) -120 deg (aka 420 deg which is injecting into the previous intake open cycle)

    So using the old method of calculating we think that the stock system is passing the 520 boundary for SOIT for the prev injection event and triggering at 420 deg (100 past boundary condition).

    Now - what if 520 boundary was a HARD limit in the ECU? What does the computer do to compensate for that?

    Well we have a "cushion" of sorts in the stock values of 110 deg normal and 30 deg makeup dont we...thats 140deg of space in a 720deg cycle.

    What if...once the SOIT hits the boundary condition of 520deg...instead of going past it...the ecu shrinks the normal and makeup numbers to compensate.

    If you think about it this makes sense - picture the stock injector at 90 or 100 duty cycle with stock boundary of 520. If normal and makeup shrunk to 0, 520 stays as a hard limit, you will never have fuel injecting into the wrong intake cycle (once you take into account the delay of fuel from spray to intake valve, and turn on delay of 0.797ms).

    Thoughts?

  2. #562
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    Dear Sir ,
    For this car I would like to fix RPM for engine limit to 500 only can you please help me how I can as I am new user
    actully this is a ICE cream selling cal owner user to keen engine start whole day . in start RPM keept @ 500 but after 2 or three hrs goes to 700 which leads to extra fuel consumption

  3. #563
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    After spending the last 3 days trying to figure out how all the formulas relate to the injector tables, I find that the version of VCM Editor that I have doesn't use the same number structure that is talked about in this thread. It appears that the tables use actual cam degrees now,no? version 4.4.2. The Boundary table and the Normal ECT look like they use degrees, while the Normal RPM table still uses 2 digit numbers. Now I guess I can spend another 3 days trying to figure this all out again....lol

  4. #564
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    With cams and lots of overlap the oxygen sensors and your AFR readings will typically run more on the lean side bc the overlap pushing extra fuel and air into the exhaust before the exhaust valve closes.
    So if your idle afr is pretty close to stoich your running on the rich side with much overlap.
    When messing with EOIT to delay the injection of fuel till after the exhaust valve closes your AFR values will typically richen up correct?
    But you still have that extra oxygen entering the exhaust. Would you still typically want to see the AFR readings more on the lean side at idle bc the extra oxygen still present in the exhaust?
    1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi

  5. #565
    Senior Tuner kingtal0n's Avatar
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    Quote Originally Posted by mild7 View Post
    Do the injection events occur as marked?
    Attachment 87253
    This must be backwards. When the yellow line is down, the injector is "on". The logic I am using is that this is showing idle which has a short pulse. So whichever way it sits most of the time is *off*.

    I think the spike in the yellow line is the inductor winding inside being turned *off* guessing

    If stock Boundary = 6.50 and Normal = 5.55 on a warm engine, and if the cam sensor is supposed to transition right at TDC compression (at least in theory, if not reality), then we should have 0 + (6.5 * 90) + (5.55 * 90) = 0 + 585 + 499.5 = 1,084.5 = 720 +364.5. We got more like 308.
    How are people supposed to use this data. A typical cam card gives EVC at .050" and advertised duration, overlap.
    So say EVC is 4* BTDC @ .050 lift and has 62* of overlap, do I split the overlap front and back to get 30-4 = 26* ATDC (random incorrect use) or some other method... there is no mention of how to clearly mark valve closing events in these relationship to degrees.

    And then assuming I get the true EVC event, do I take this number against the factory's realistic 308* (assuming this is crank degrees and 360* = tdc exhaust) Or use the spreadsheets assumption of ~350* instead of 308* that was found, next issue:
    SO guessing more, maybe it needs 360+26* = 386* from 308 = 386 - 308 = 78* so lets say 80* just to put EOIT on top of EVC, so next add injector spray time,
    big enough injector looks like it takes 10-20* of crankrevolution so lets go 80* + 20* = 100*
    Since each 1.0 = 90* it looks like I need to add about 1.05 to the "normal" table to "fix" the injector spray




    Next I open the excel spreadsheet and the first input at the top is "normal". Which is what you opened the file to figure out in the first place. So I thought that was strange.
    The rest is just numbers in degrees, I get that. 365, 450, etc...
    But what does that tell you? There is no indication of how to use these numbers.
    Camshaft input boxes are obscure, asking for EVC and IVO without label whether it wants .006 or .050"

    So I just looked it over and it and the only thing I can even guess at is that "6.5" in the normal table (no mention of "makeup") shows SOIT 435*
    And also that 5.55 gives 350*
    Which is also confusing since the data above suggested in reality it was 308*

    So this is all very confusing and without graph labels, correlation from EOIT to exhaust valve close events, vague spread sheets, still need packaging and deployment
    Last edited by kingtal0n; 07-04-2019 at 04:22 PM.

  6. #566
    Senior Tuner kingtal0n's Avatar
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    Something like this is what I would have expected at the end of all this research and equipment
    newlscrankeoitchart.png

    Thats just an example. I have no idea if it is correct. I used whatever was given to me from the above information. So if its wrong, that only shows how difficult it is currently to interpret the data that was found.
    there is still much left a mystery as evidenced I hope with this picture

  7. #567
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    Still trying to understand the mystery of LS1 EOIT

    https://pcmhacking.net/forums/viewtopic.php?f=28&t=6396

  8. #568
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    I see this post pop up a lot, haven't read all the comments but I see a lot of questions. My trials were posted early in the pages of this thread.

    I did some street and dyno testing with this. Made zero difference in power throughout the entire RPM range at WOT. Not sure about part throttle/lower loads.
    Sulski Performance Tuning
    2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
    2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB

  9. #569
    Advanced Tuner IARLLC's Avatar
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    Yeah, with a stock/very small cam I don't see any difference in power. I know GHuggins got some fuel economy improvement on stock GEN5s with careful EOI adjustment.

    For increased overlap cams EOI makes a HUGE difference in drivability, emissions, torque.

    Also any time we are getting close to the end of the injectors' ability to do their job within parameters, especially GEN5

  10. #570
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    Quote Originally Posted by IARLLC View Post
    Yeah, with a stock/very small cam I don't see any difference in power. I know GHuggins got some fuel economy improvement on stock GEN5s with careful EOI adjustment.

    For increased overlap cams EOI makes a HUGE difference in drivability, emissions, torque.

    Also any time we are getting close to the end of the injectors' ability to do their job within parameters, especially GEN5
    How does it effect driveability?
    1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi

  11. #571
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    I should have added I was just comparing for Gen III stuff.

    I had a 230/232 112+4 and 236/244 110+4 (the grind was actually missed, supposed to be on a 112) and saw nothing WOT wise. I never tested enough to check fuel economy.
    Sulski Performance Tuning
    2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
    2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB

  12. #572
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    Quote Originally Posted by anniversaryss View Post
    How does it effect driveability?
    Often stock injector timing with a larger overlap cam results in watering eyes and a terribly unstable idle...as loads of fuel get sprayed right past the open valves into the exhaust. Even a very small change in injector timing can help clean up idle, throttle response, launch, etc.

  13. #573
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    Quote Originally Posted by anniversaryss View Post
    How does it effect driveability?
    Just like an untuned carb dumping fuel..rich, stinks, clogged cats, decreased MPG's etc..

  14. #574
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    I don't agree with injecting fuel with the intake valve open/after the exhaust valve closes. Do as OEM intended and spray on the back of a closed valve. The temporary gain in idle stability isn't worth the long term effect of washing your cylinders/oil out with fuel.

  15. #575

    Injector timing

    Have been following this thread, its nice there are others out there also wanting to learn the hows and whys of things like this, and figured I would try to contribute my findings so far.

    Short version; based on the most thorough testing I could achieve (without a dyno and weeks of time) I have only been able to produce negligible to inconclusive differences "on paper" and nothing in the way of "seat of the pants" between stock and delayed injection timing on a decent overlap cam in a 383 ls6. I might be missing something though, so am open to feedback!

    Long version; TSP built 383 (10.9:1 compression and 237/243 @.050, .622/.624 112+2 cam), GM 3.8 GTP / ASA injectors and correct data, dialed in VE / timing / airflow in SD/OL and now with all fuel/air/idle learning disabled, started to do some testing with injector timing to see if I could finally get rid of a nasty surging/bucking at very light (neutral) load below 1600rpm. As far as the bucking goes, no injection timing between 5.55 and 7.2 EOIT ref. periods made any difference.

    For my testing setup, I started with the first good data I came across to describe the timing events (big thanks to Bluecat for his testing and contribution) and assumed that the stock injection timing was based on the formula ((bound+norm)*90)-784 which put it at 300.5 after compression TDC. Based on my valvetrain events, a value of 7.2 EOIT ref. periods was what I determined would theoretically START the injection just after exhaust valve closure at the particular RPM and injector pulse width my surging/bucking was occurring at, as well as all of the idle and light load/rpm conditions. SOIT would then back up into valve overlap again at high RPM/load but at that point I figured the IPW was so much longer that the relative amount of fuel lost should be smaller anyway. I plotted my valve events and injector events in excel and then was able to modify my EOIT, IPW, and RPM based on known operating conditions to see where it all fell out. The example screenshot attached is showing my cam with the one green line representing the stock injector timing values (5.55 norm) and the other representing the delayed 7.2 norm value at 1600 RPM and 3.0ms IPW.

    5.55 vs 7.2 EOIT example 1600rpm 3.0ms IPW.PNG

    "seat of the pants" I honestly wouldn't be able to pick either setting out in a "blind" test in any operating conditions. I also did a visual tailpipe filter and smell check of the exhaust at idle since I figured it would show up most there but at normal operating temp again wouldn't bet anything on being able to pick which was which. I did however try delaying the cold coolant temp values and during cold start it was noticeably less "clean" with the delayed timing (spraying into open intake valve), so I do feel like that may further validate the point that the stock injection happens on a closed intake valve, even earlier when cold, to vaporize the fuel better.

    As far as numerical findings, I need to compile them into a single table, but I would tend to call them negligible differences in any parameters observed during steady state idle, 20%TPS accel 1-3krpm, 35%TPS accel 1-4krpm and 100%TPS accel 1-6krpm. Oddly enough though, if I look at the cumulative trend at idle, the stock injector timing actually produced higher RPM, consumed less air to do it, held more manifold vacuum, and showed a richer WBO2 reading, at the same TPS% as the delayed injector timing! Talking +/-1% for the most part in all testing though, but still opposite of what I expected.

    I thought my camshaft was fairly aggressive, but maybe its just not big enough for injection timing to make a difference on? or maybe my normal operating temp injection timing settings aren't actually taking for some reason? (would be a bit extreme, but cool to have high enough data rate/fidelity to monitor injector on/off status vs crank position!) Interesting topic here for sure. May just be yet another parameter that every particular engine setup wants something completely different on...
    Last edited by CaudleDynamicsLLC; 10-08-2019 at 01:41 AM.

  16. #576
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    Quote Originally Posted by CaudleDynamicsLLC View Post
    Have been following this thread, its nice there are others out there also wanting to learn the hows and whys of things like this, and figured I would try to contribute my findings so far.

    Short version; based on the most thorough testing I could achieve (without a dyno and weeks of time) I have only been able to produce negligible to inconclusive differences "on paper" and nothing in the way of "seat of the pants" between stock and delayed injection timing on a decent overlap cam in a 383 ls6. I might be missing something though, so am open to feedback!

    Long version; TSP built 383 (10.9:1 compression and 237/243 @.050, .622/.624 112+2 cam), GM 3.8 GTP / ASA injectors and correct data, dialed in VE / timing / airflow in SD/OL and now with all fuel/air/idle learning disabled, started to do some testing with injector timing to see if I could finally get rid of a nasty surging/bucking at very light (neutral) load below 1600rpm. As far as the bucking goes, no injection timing between 5.55 and 7.2 EOIT ref. periods made any difference.

    For my testing setup, I started with the first good data I came across to describe the timing events (big thanks to Bluecat for his testing and contribution) and assumed that the stock injection timing was based on the formula ((bound+norm)*90)-784 which put it at 300.5 after compression TDC. Based on my valvetrain events, a value of 7.2 EOIT ref. periods was what I determined would theoretically START the injection just after exhaust valve closure at the particular RPM and injector pulse width my surging/bucking was occurring at, as well as all of the idle and light load/rpm conditions. SOIT would then back up into valve overlap again at high RPM/load but at that point I figured the IPW was so much longer that the relative amount of fuel lost should be smaller anyway. I plotted my valve events and injector events in excel and then was able to modify my EOIT, IPW, and RPM based on known operating conditions to see where it all fell out. The example screenshot attached is showing my cam with the one green line representing the stock injector timing values (5.55 norm) and the other representing the delayed 7.2 norm value at 1600 RPM and 3.0ms IPW.

    5.55 vs 7.2 EOIT example 1600rpm 3.0ms IPW.PNG

    "seat of the pants" I honestly wouldn't be able to pick either setting out in a "blind" test in any operating conditions. I also did a visual tailpipe filter and smell check of the exhaust at idle since I figured it would show up most there but at normal operating temp again wouldn't bet anything on being able to pick which was which. I did however try delaying the cold coolant temp values and during cold start it was noticeably less "clean" with the delayed timing (spraying into open intake valve), so I do feel like that may further validate the point that the stock injection happens on a closed intake valve, even earlier when cold, to vaporize the fuel better.

    As far as numerical findings, I need to compile them into a single table, but I would tend to call them negligible differences in any parameters observed during steady state idle, 20%TPS accel 1-3krpm, 35%TPS accel 1-4krpm and 100%TPS accel 1-6krpm. Oddly enough though, if I look at the cumulative trend at idle, the stock injector timing actually produced higher RPM, consumed less air to do it, held more manifold vacuum, and showed a richer WBO2 reading, at the same TPS% as the delayed injector timing! Talking +/-1% for the most part in all testing though, but still opposite of what I expected.

    I thought my camshaft was fairly aggressive, but maybe its just not big enough for injection timing to make a difference on? or maybe my normal operating temp injection timing settings aren't actually taking for some reason? (would be a bit extreme, but cool to have high enough data rate/fidelity to monitor injector on/off status vs crank position!) Interesting topic here for sure. May just be yet another parameter that every particular engine setup wants something completely different on...
    Good write up. I get some bucking usually between 2 to 3k.

    I do however believe i was able to reduce the bucking with EOIT just around/ after the valve closes.

    I did notice a loss in vac at idle but its inconclusive bc i noticed my tune was commanding my idle 150 rpm higher than what the tune was, so when i reflashed it went to down to what my tune was calling for. The loss of vac could have been from the idle drop. I was able to get some back with timing but i need more testing and with a big cam on stock cubes you need whatever vac you can get lol
    1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi

  17. #577
    I've tested it on my Camaro with some mixed results. I can say there is a noticeably different amount of raw fuel smell in the air, as well as a slight increase in richness on the VE in a few areas. I can't say how much of a difference really, since I did a cam change, and most of the testing I did was on the previous cam. I didn't mess with it again, because it was tough enough getting the car to idle nice again, coupled with having injector data that kept me way too rich on decel. I since reduced the minimums on injectors to nearly half the original values to get control over the overspray on decel. So that didn't help in determining if the EOIT was helping or not.

    Now, I will say for a fact, that you can get a huge cam to idle with the perfect settings, to include EOIT. The current cam is (seat to seat values) 297/305 114+4 .633/.633, 93 degrees of overlap. .050 values are 244/252, 20* overlap. Car idles great at 700, and I've had it set as low as 638. My EOIT is set right at 360*, because I am figuring that even at idle, some of that fuel going down the pipe is getting pulled back in through scavenging. It's also a 427 stroker, so an interesting animal to tune on. Only stock parts are the block and heavily modified heads lol. Maybe a few of the bolts here and there too, but can't say for sure.

    Here's the log where I commanded the idle down. So this can be done, not sure how much it has to do with EOIT though, which again is set at 360* on that big ass cam. My daughter still calls it the smelly Camaro though, so not sure really how much of an effect it has on the smell really. I think it's better, but it's awfully subjective. I'd like to test some more on it in the future. I also like doing excel math, and recently I was working on ways to backwards calculate fuel transients and their "units" and perhaps a way to tune them without guessing. That's another animal though.

    Super Low Idle test.hpl

    Here's a pic if you don't feel like firing up the scanner lol. I know sometimes I don't feel like it.

    Super low idle.PNG

  18. #578
    Senior Tuner kingtal0n's Avatar
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    I think the fuel sitting on the valve, can evaporate long before the intake valve opens, and some of of the fuel escapes, back into the manifold, or even out the throttle body sometimes, due to the reversion of the cam (bigger cams can spit fuel back into carbs etc...). The stock cam probably sips the intake runner effectively enough that the high column of vaporized fuel hanging in a well designed runner tube doesn't get much a chance to escape. I tried the 6.5~range settings with the OEM camshaft over a year ago and noticed very little if any difference so I put it back to stock 5.55 until recently.

    So it would seem a general idea then emerges for those of us running shorter-modified runner manifolds and larger than stock camshafts, that is, to inject the fuel as late as possible in order to conserve it within the chamber or runner (direct injection is the next step) thus maximizing fuel savings.

    couple risks
    Since we cannot inject at very high pressure (1500psi or whatever) there is a risk of fuel puddle if the fuel is injected cold, and the engine is cold. Furthermore there is no way to tell when the intake valves are 'very hot' or the engine is actually vaporizing fuel easily to avoid fuel puddling. Some of the fuel injected may be integral with cooling the valve or have something to do with long term stability of intake valve. I noticed they look quite different engines. You could say "but Civvie the exhaust valves do just fine" and to that I would reply "yes, but, we don't know if the intake valve manufacturer or engineers who designed the engine used different materials or science behind the design of the intake valves that depends on the cooling effect interactions of fuel vaporization" I just don't know is all I'm saying, from random search [https://www.quora.com/What%E2%80%99s...exhaust-valve]
    Inlet valves are made of Silicon -chromium steels containing about 0.4% carbon, 3.5% Silicon, 0.5% nickel, 0.5% manganese, 5% chromium.
    The exhaust valves are made of about 0.25% carbon, 0.25% Silicon, 9% manganese, 4% nickel, 21% chromium and 0.4% nitrogen. It is designated as 21–4 N austenitic steel. For heavy duty engines, the exhaust valves are made of nimonic alloys but they are costly.
    also random articles here on this site can give insight "valve design" if you had time, like this one
    http://www.sbintl.com/tech_library/a...and_alloys.pdf


    Fuel puddle/cling can remove oil film from surface of cylinder walls, it may facilitate engine cylinder bore wear. The rate of vaporization can vary and there maybe tipping point where so much fuel cools things down so far that sudden fuel begins to cling and puddle. The most annoying part of these risks is we have very little insight as to how well(how fast) and where/when the fuel is vaporizing from outside the machine.


    technology
    some computers can adjust injection timing per RPM, not just temperature.
    Injectors will be starting to inject fuel much earlier at high RPMS anyways if it's anywhere near WOT at high duty cycle
    In other words there is no way to avoid spraying fuel to the back of an intake valve at WOT if the injector gets to a high duty cycle. I think the risk at WOT is minimized for a variety of reason and this injector spray setting is mostly for cruise/idle conditions. You want the late injection to keep the fuel where it belongs near idle and cruise when fuel mass is low and easy to vaporize.

    experiment
    First I tried having all the fuel in just a ways after overlap, 6.5 to 6.7 normal with the usual boundary 6.5.
    Noticed immediate improvement in a/f ratios (richer) in cruise and idle regions when fully warm with the mild cam TFS-30602001 @ 5.3L
    Then I took my cam card and found advertised duration rough intake valve opening point 327* (open to .050" by 2*ATDC) and put my end of injection right near that,
    so (5.9+6.5)*90-786 = 330*
    That way the fuel is injected later than factory, but still has a brief moment to touch and cool the intake valve just before it begins to crack open as the piston is moving up, which I think pushes the fuel away from the intake valve slightly for an instant. Then hopefully it can glide through overlap before any fuel is in the cylinder.

    And I am still rich everywhere. I'm pulling fuel out of the VE map around 2% VE (a fuel savings of roughly 5%) some spots. I think this later spraying is conserving fuel within the intake runner and it's early enough that I keep most of what I spray now AND it still hits the back of the intake valves which I can tell by looking down the runners has a slight cleaning effect as well. I can't wait to test fuel economy difference next.
    Last edited by kingtal0n; 10-08-2019 at 12:00 PM.

  19. #579
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    Interesting. Let us know how the fuel economy turns out.

    I've think some issues come from not adjusting after a cam change. Depending on valve events it could lead to bad injection moments which could contribute to bucking/smell. I always look at stock injection with stock cam/valve events and adjust to match those. I'm paranoid having fuel wash the cylinders down and degrade the oil.

    I use to adjust to after the exhaust valve closes. I think I've mentioned this before but I could just tell something wasn't right when I changed my oil. It didn't feel right and smelled like fuel/acid like if that makes sense. Oil sample proved my concerns. Since moving away I haven't had any issues with this. I did not keep track of fuel economy though. Idle is still stable too just had to spend more time with throttle/spark correction, VE, about idle airflow.

  20. #580
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    Quote Originally Posted by kingtal0n View Post
    I think the fuel sitting on the valve, can evaporate long before the intake valve opens, and some of of the fuel escapes, back into the manifold, or even out the throttle body sometimes, due to the reversion of the cam (bigger cams can spit fuel back into carbs etc...). The stock cam probably sips the intake runner effectively enough that the high column of vaporized fuel hanging in a well designed runner tube doesn't get much a chance to escape. I tried the 6.5~range settings with the OEM camshaft over a year ago and noticed very little if any difference so I put it back to stock 5.55 until recently.

    So it would seem a general idea then emerges for those of us running shorter-modified runner manifolds and larger than stock camshafts, that is, to inject the fuel as late as possible in order to conserve it within the chamber or runner (direct injection is the next step) thus maximizing fuel savings.

    couple risks
    Since we cannot inject at very high pressure (1500psi or whatever) there is a risk of fuel puddle if the fuel is injected cold, and the engine is cold. Furthermore there is no way to tell when the intake valves are 'very hot' or the engine is actually vaporizing fuel easily to avoid fuel puddling. Some of the fuel injected may be integral with cooling the valve or have something to do with long term stability of intake valve. I noticed they look quite different engines. You could say "but Civvie the exhaust valves do just fine" and to that I would reply "yes, but, we don't know if the intake valve manufacturer or engineers who designed the engine used different materials or science behind the design of the intake valves that depends on the cooling effect interactions of fuel vaporization" I just don't know is all I'm saying, from random search [https://www.quora.com/What%E2%80%99s...exhaust-valve]


    also random articles here on this site can give insight "valve design" if you had time, like this one
    http://www.sbintl.com/tech_library/a...and_alloys.pdf


    Fuel puddle/cling can remove oil film from surface of cylinder walls, it may facilitate engine cylinder bore wear. The rate of vaporization can vary and there maybe tipping point where so much fuel cools things down so far that sudden fuel begins to cling and puddle. The most annoying part of these risks is we have very little insight as to how well(how fast) and where/when the fuel is vaporizing from outside the machine.


    technology
    some computers can adjust injection timing per RPM, not just temperature.
    Injectors will be starting to inject fuel much earlier at high RPMS anyways if it's anywhere near WOT at high duty cycle
    In other words there is no way to avoid spraying fuel to the back of an intake valve at WOT if the injector gets to a high duty cycle. I think the risk at WOT is minimized for a variety of reason and this injector spray setting is mostly for cruise/idle conditions. You want the late injection to keep the fuel where it belongs near idle and cruise when fuel mass is low and easy to vaporize.

    experiment
    First I tried having all the fuel in just a ways after overlap, 6.5 to 6.7 normal with the usual boundary 6.5.
    Noticed immediate improvement in a/f ratios (richer) in cruise and idle regions when fully warm with the mild cam TFS-30602001 @ 5.3L
    Then I took my cam card and found advertised duration rough intake valve opening point 327* (open to .050" by 2*ATDC) and put my end of injection right near that,
    so (5.9+6.5)*90-786 = 330*
    That way the fuel is injected later than factory, but still has a brief moment to touch and cool the intake valve just before it begins to crack open as the piston is moving up, which I think pushes the fuel away from the intake valve slightly for an instant. Then hopefully it can glide through overlap before any fuel is in the cylinder.

    And I am still rich everywhere. I'm pulling fuel out of the VE map around 2% VE (a fuel savings of roughly 5%) some spots. I think this later spraying is conserving fuel within the intake runner and it's early enough that I keep most of what I spray now AND it still hits the back of the intake valves which I can tell by looking down the runners has a slight cleaning effect as well. I can't wait to test fuel economy difference next.
    So your saying you adjusted your EOIT to right after the intake valve opens trying to still utilize the evaporation technique as it was but still moving injection timing later to aid in helping the cam work more efficiently?

    Hows the idle smell? Do you feel the car runs better right after the IVO or after the EVC?

    Im not entirely sure if i like how it runs with it right after the EVC but it did get rid of the fuel smell. But if i move it toward the IVO with better results then i can deal with some smell.

    Ill do some calculations later and see what i find out.
    1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi