Injection Timing Assistance Requested

[adunphy]

Great work here! (talk about the lazy man's approach to a fairly complex topic... You guys nailed it!)

I spent a few hours "test driving" the sheet. I tried various examples and the one that is the most perplexing to me is taking the known cam specs and logged IPW for a WOT pull on the dyno and then pasting in the stock Injector timing settings from the ECU. (in other words with cam+injectors+boost and no changes to stock inj timing.) I've attached the demo below. Should I really conclude that the stock injector timing is this far off or are the diagrams just making it look worse than it is? Specifically have a look around 3072 - 4096 RPM. I tend to rely more on the math and graphs in this worksheet, but this just has me scratching my head on how this thing even runs! (and pulls pretty hard too)

INJECTOR TIMING TOOL GEN IV - Black Charts-FRCv16_Cam+turbo+injectors+stockboundary.xlsx

[schpenxel]

Yes, I am absolutely killing it.

Gimme some stocks!

[Area47]

W00t, im gonna try this out tonight actually.

[IXR08]

ok so what values do you load into your tune once you have populated the sheet?

[07GTS]

all the adjusted "input" values that u have changed to suit your eoit timing, put your current settings in then adjust to suit your cam then copy back into tune file and see how it goes

[IXR08]

all the adjusted "input" values that u have changed to suit your eoit timing, put your current settings in then adjust to suit your cam then copy back into tune file and see how it goes

ok so to check im doing it right what values do you get with this cam: 235/244/.647/.612/111 LSA (these values are @50) i don't know the 0.6 values.

[07GTS]

its better if u can find the .006 values otherwise u will have to account for a little more which can have a decent difference, if u input your values it will show u visually what is going on then u just have to change your inputs to suit where u want the soit/eoit

[Michael_D]

Damn you guys have been busy!! I've almost got my 'new' engine back together and logged on to find Carson's spreadsheet for the new cam and injectors and found this thread. Wow, just wow.

[J-CUE]

Those of you that retard EOIT, is it only at high RPM's?
If it's also at mid range, how are you not getting cylinder wash?

[GHuggins]

Those of you that retard EOIT, is it only at high RPM's?
If it's also at mid range, how are you not getting cylinder wash?

Plug a stock injection timing table into the spreadsheet - might realize some things Factory targets PPV at idle and low rpms - they only start advancing it at cruise and higher rpms and stock actually has the ability to inject as the intake valve is closing with high enough rpms... I haven't personally had any issues with wash setting up the injection timing how I do it - there's a demonstration a page back do demonstrate how I do it... Newer Gen5's inject fuel straight into the cylinder after the exhaust valve closes at very high pressure... As long as you have the turbulence or something to "beat" or atomize the fuel in some regards - you shouldn't have problems...

[J-CUE]

So, when EOIT is after IVO, target EOIT between PPV and Peak Intake Charge Velocity (PICV)?

Makes sense.
Thanks!

[schpenxel]

Damn you guys have been busy!! I've almost got my 'new' engine back together and logged on to find Carson's spreadsheet for the new cam and injectors and found this thread. Wow, just wow.

Yeah, the community here really put together a nice sheet for this one..

[scottt28]

Gimme some stocks!

I was daytrading options for bank stocks. BAC was my biggest winner. Party over now.

Spending every day adding Precision 88mm Pro Mod turbo to truck. Hoping I can get it running tomorrow without too many issues

[adunphy]

again...love this sheet. Awesome piece of collaborative work!

So, I've got an ISKY cam and they measure at .007 instead of .006. On the input sheet, cell D2 does not appear to be referenced anywhere. I've updated the "Table" sheet and on row 21, 23 and 25 used references as follows: =Input!$D$2 to make it dynamic based on data in the input sheet.

In this case all it does is slightly lifts the bell curves off the x-axis a bit more and narrows the visible overlap range as well as EVO and IVC. (you can exaggerate this by using advertised 0.050 and see what I mean)

Not sure if this is even worth the time or if this was already obvious to everyone. (feel free to correct my logic if I've mis-applied it!)

[scottt28]

again...love this sheet. Awesome piece of collaborative work!

So, I've got an ISKY cam and they measure at .007 instead of .006. On the input sheet, cell D2 does not appear to be referenced anywhere. I've updated the "Table" sheet and on row 21, 23 and 25 used references as follows: =Input!$D$2 to make it dynamic based on data in the input sheet.

In this case all it does is slightly lifts the bell curves off the x-axis a bit more and narrows the visible overlap range as well as EVO and IVC. (you can exaggerate this by using advertised 0.050 and see what I mean)

Not sure if this is even worth the time or if this was already obvious to everyone. (feel free to correct my logic if I've mis-applied it!)

Correct... the input value of .006 was not being used. In version 18 attached, I referenced the cell in lines 21, 23, and 25 of the "Table" sheet tab. I did a random check on the "Graph" sheet tab, and the formulas were correct - so no changes needed there. As you noticed, it doesn't really show much. It basically raises or lowers the starting points for the curves along the horizontal axis...

[liquidforce917]

Looking for a little clarification after reading ALL 11 pages yesterday! (For reference vehicle is a bolton LS3 Vette with a mostly stock tune.)

To calculate EOI the ECU will reference the Boundary Table with respect to the current RPM, the Normal RPM IF under 4,096rpm, and the Normal ECT. Lets assume the Normal ECT is at operating temp and its value is 110, The Boundary is 465, and the Normal RPM is 93. Given these conditions the End of Injection will be 465-110-93= 262? Is that correct?

How does the Makeup get factored in?

Can I get some suggestions for how far I can retard EOI for my stock cam to gain more efficiency?

[07GTS]

boundary - ECT - RPM -Makeup = EOIT zero out the RPM and use boundary as the rpm for full scale, easiest start is to make boundary all 520 then lower ECT at idle till ur after EVC then u know where ur at with your valve events, then adjust the boundary after idle to delay or advance what ever u want to do for cruise economy or power up top, this is with RPM all zero, if u go up and down in the boundary keep it smooth, for cruise just adjust it and see what it likes go for a drive and see if your instant fuel usage gets better or worse for the same driving and adjust to suit it can make a big difference especially if u go the wrong way

[liquidforce917]

boundary - ECT - RPM -Makeup = EOIT zero out the RPM and use boundary as the rpm for full scale, easiest start is to make boundary all 520 then lower ECT at idle till ur after EVC then u know where ur at with your valve events, then adjust the boundary after idle to delay or advance what ever u want to do for cruise economy or power up top, this is with RPM all zero, if u go up and down in the boundary keep it smooth, for cruise just adjust it and see what it likes go for a drive and see if your instant fuel usage gets better or worse for the same driving and adjust to suit it can make a big difference especially if u go the wrong way

What I have done: Zeroed out Normal RPM, and added 130 degrees to the stock Boundary Table. This puts me at EOI of 527 degrees (at idle) with the stock IVC of 579 @0.050. This should be pretty conservative considering 52 degrees away from the intake valve closing. I will report back.

[07GTS]

try to inject as the EVC is happening so it also gets good vaporizing going on, leaving it so it only has 52 deg before the IVC is too late if u stab the throttle it may not have enough time to get the first crack of fuel in, i have my idle injection ending around PPV or just before depends on your PW, if u crack the throttle it should stay nice and responsive

[GHuggins]

What I have done: Zeroed out Normal RPM, and added 130 degrees to the stock Boundary Table. This puts me at EOI of 527 degrees (at idle) with the stock IVC of 579 @0.050. This should be pretty conservative considering 52 degrees away from the intake valve closing. I will report back.

You won't like it. Target ppv for the most part at all times. Or in other words have SOI about the same distance from ppv as EOI. If it's a stock cam - don't retard as much.