Been spending a bit of time with SOIT/EOIT and have a few questions.
Sorry if the post is a bit lengthy but lots to cover.
I had someone here help me setup my SOIT\EOIT a couple months back, now wanting to just optimize it a bit in the transition area from the off idle area(1500-2000RPM) to 4000 RPM, if its even necessary as the car is running quite well.
I'm not really experiencing anything negative as far as drivability goes but when making adjustments like advancing the injection timing a bit later the car feels a wee bit lazier going into the max injection advance area.
I've included my tune, screen shots of graphs for EOIT/SOIT timing.
Here are my Cam specs for SOIT/EOIT
282/297 advertised duration (.006")
IVO - 32 degrees BTDC
IVC - 70 degrees ABDC
EVO - 83.5 degrees BBDC
EVC - 33.5 degrees ATDC
Overlap is 65.5 degrees
The boundary angle is set to 470 and the higher RPM is 580, with the transition starting at 2500-4000 Here is the reasoning and calculations behind this
EOIT sets the Boundary at idle to 470 so that no matter what, fuel is not sprayed "in the danger zone" of getting reversed. IVC is 610, BDC is 540, 610-540 is 70. So 540-70=470.
EOIT at higher RPM sets the Boundary angle to occur 30 degrees before the IVC. IVC is 610, so EOIT or the Boundary angle is 580.
Make up mode has been turned off.
I have played with SOIT at idle and have determined that 389 degrees is the "sweet spot" with the richest STFT.
389 degrees is 4.5 degrees before the EVC. This really cleaned up the raw fuel smell as well.
As far as the boundary angle of 580, the car pulls extremely well and hard above 4000 RPM, so I am only assuming the 580 boundary angle is correct.
EOIT-SOIT Tables.jpg
So for right now I am playing with the transition from say (1500-2000RPM) to 4000 RPM and I am just wondering If I am on the right track.
I have not modified the Boundary table at all, as I am only shifting the Normal RPM table right or left to either advance or retard the SOIT transitioning from the idle area to 4000 RPM.
I have to be honest, I have started the transition as low as 1400 RPM and as high as 2900 RPM and the only thing I notice, is if I advance it at a later RPM the engine just feels a bit lazier transitioning into higher RPM.
I fully expected to feel bucking and jerking or hiccupping in the the lower RPMS, but felt nothing.
I have about 10 different settings I tried and flashed to the ECM and have included them in an EXCEL spread sheet, which I have attached here.
I made sure my Normal RPM tables values were changed to have a smooth transition of SOIT values going from low RPM to High RPM.
The SOIT formula is SOIT=SOIT- NORMAL ECT- NORMAL RPM - MAKEUP ECT(if used) - MAKEUP RPM(if used)
I belive the Injector PW value is added to the SOIT after the value is found.
From what I understand you can use any combination of numbers on your boundary table, Norma ECT and Normal RPM table to achieve the actual SOIT value.
I know there are many different opinions on SOIT/EOIT here, but I am not trying to start a thread on opinions about that
I know I was told to watch the STFT values going from low RPM to High RPM, but I could not get any kind of a stable reading to make any kind of call using STFT's as I am only doing street tuning and don't have a DYNO
I have used Cringers EOIT program and plugged all my values into including injector PW and I do understand how his program lays everything out.
EOIT Assistant.jpg
I have also got my hands on the Injector Timing tool by black charts and put all my data in there. Now it seems a bit more complex than Cringers EOIT tool, but I am not sure how to properly read the SOIT and SOIT-FRC values. The SOIT and SOIT-FRC(green Lines) drop to the bottom of the graph from idle to 3500 RPM but then spike to the top of the graph by 4000 RPM. I am not seeing the pattern of this in the EOIT assistant program.
I have included a screen shot of the graph and the excel spread sheet.
Injection Timing Tool Graph.jpg
I do have a basic understanding on how the SOIT/EOIT works with valve timing along with the boundary angles what I am struggling with is the SOIT/EOIT transition from low to high RPM. I am just looking for some guidance on this as I cant really notice much in the way the car behaves during the transition, other than the bit of laziness on the later injection timing when the transition RPM is raised.
I am tempted to just leave it alone and have the transition start at 2000 RPM as it is in my tune, unless any of you guys spot something obviously wrong and are able to explain why its wrong and what I should do to correct it?
INJECTOR TIMING TOOL GEN IV - Allens Vette.xlsx
SOIT-EOIT Work Sheet.xlsx
Current Tune.hpt