Injection Timing in 2024

[Big Biscuits]

It seems that every time I read a thread about injection timing on here it changes. Old 2012 DSteck way was to leave the boundary and rpm stock and change the ECT to get the SOIT past the EVC. Not much info on the higher rpm tuning.

Now I read more about zero out RPM and set ECT for idle richness and throttle snap. I see a lot of boundary changes in every direction. Small to large ramp up in rpm, and large to small ramp down with rpm. Stock tunes look like the SOIT is sooner as the rpm increases. If you zero the normal rpm table, and change the ECT table to a lower value from 110 to 90 or so, the SOIT pushes past the EVC target up around 1,152 rpm. All according to the EOIT spread sheet. If boundary is not changed, the EOIT is around PPV. If you change boundary in the higher rpm, what is the target supposed to be? I also read that the old targets in the spread sheet past 4000 rpm are not valid now due to new things learned from testing. GHuggins has said he rarely pushes the boundary out past 575 to 610. If I target the old 20-30* before IVC I would be in the 635 boundary area.

I am confused on which way to go. Old way, 2018 way, or whatever the correct way is now.

Car Specs: 2010 Camaro E38 ecm
408 iron, 10.4:1 CR
242/258 116 LSA 113 ICL .629/.612 lift @ .006- 297/313 Cam motion
ID1300X injectors
ESS G4-95mm Centri blower Max effort 20+ psi

Excel snapshot
408.G4.87.Startup.E85.LTFT.8.3.hptScreenshot 2024-04-09 094816.png

[Cringer]

It seems that every time I read a thread about injection timing on here it changes. Old 2012 DSteck way was to leave the boundary and rpm stock and change the ECT to get the SOIT past the EVC. Not much info on the higher rpm tuning.

Now I read more about zero out RPM and set ECT for idle richness and throttle snap. I see a lot of boundary changes in every direction. Small to large ramp up in rpm, and large to small ramp down with rpm. Stock tunes look like the SOIT is sooner as the rpm increases. If you zero the normal rpm table, and change the ECT table to a lower value from 110 to 90 or so, the SOIT pushes past the EVC target up around 1,152 rpm. All according to the EOIT spread sheet. If boundary is not changed, the EOIT is around PPV. If you change boundary in the higher rpm, what is the target supposed to be? I also read that the old targets in the spread sheet past 4000 rpm are not valid now due to new things learned from testing. GHuggins has said he rarely pushes the boundary out past 575 to 610. If I target the old 20-30* before IVC I would be in the 635 boundary area.

I am confused on which way to go. Old way, 2018 way, or whatever the correct way is now.

Car Specs: 2010 Camaro E38 ecm
408 iron, 10.4:1 CR
242/258 116 LSA 113 ICL .629/.612 lift @ .006- 297/313 Cam motion
ID1300X injectors
ESS G4-95mm Centri blower Max effort 20+ psi

Excel snapshot
408.G4.87.Startup.E85.LTFT.8.3.hptScreenshot 2024-04-09 094816.png

The correct way is going to involve a dyno and lab grade emissions testing equipment IMHO.

There several different ideologies and methods. It is something I have spent considerable time on and put my thoughts and work here:
My views on EOIT theory: https://youtu.be/Td6oC9CIUas
My EOIT Tool to replace the spreadsheets: https://youtu.be/4AHS5a3lqkQ

A lot of people will say EOIT has minimal gains and impacts and to only worry about taming the idle fuel smell. The benefits and effects from this are going to be largely dependent on the cam you have. FWIW I recently tuned a car that was getting 11mpg and now gets 17 mpg just from EOIT alone.

I suppose you can try all different methods and see which one yields the best fuel trims and drivability.

[Big Biscuits]

Thank you sir! lots of great info and a useful tool to boot. I have to add some stuff to my scanner and input some values. I also need to sit down away from distractions to really pay attention to the videos.

[ns158sl]

I'd say play with it but at the end of the day, Dave aligns with Banish and other OEM calibrators.

[Big Biscuits]

I'd say play with it but at the end of the day, Dave aligns with Banish and other OEM calibrators.

That is true. I remember reading that long ago.


Cringer, Do you want me to PM you questions, or post them up? I think I have it going in the right direction.

[Cringer]

That is true. I remember reading that long ago.


Cringer, Do you want me to PM you questions, or post them up? I think I have it going in the right direction.

Just post them here.

[Big Biscuits]

Here are a few screen shots of what I am looking at currently. Moved things around to stay in the targets suggested. I am high boost and E85 so I would think I need to allow as much time as possible to inject fuel at high rpm. I sent you a PM on the other questions.