Injector timing spreadsheet-anyone familiar?

[LS ROB]

INJECTOR TIMING TOOL GEN IV - Final.xlsx

i used this excel spreadsheet to adjust injector timing, then i dialed in my Injector tip temps.. My question is, how accurate is the spreadsheet? the car definitely feels better and im hoping that ive not adjusted things too much. i have attached my current tune in hopes that someone with experience will chime in. after itt.hplinjector & itt tune.hpt

[GHuggins]

If what you came up with is working for, then go with it, but honestly it looks too retarded from my experiences. Typically more retarded WILL give you more torque, but you have to watch out on drive-ability as it can cause stumbles and other transient issues. I also haven't found any further benefit going above 575 anymore.

As for your itt table - typically up to around 55 will be 0's - if not then your base fueling is usually off.

Again, nothing wrong with any of this if it's working for you. Other areas may be a little off making this work well in your specific case.

That timing tool was originally created by members on here going off of my own personal preferences from the R&D I did on the subject way back when. I originally started using degree wheels and this was evolved from that. Credit goes to the guys that made it. There were about 4 or 5 if memory serves that added to and made changes to it. Wish they were still around here...

[LS ROB]

i am still getting the bucking where my timing dips but i think thats a different issue. could be wrong about that though. however, the difference when adjusting this, was noticeable. now that i have the itt and injection timing, should i go back and redo the MAF then VVE?

[07GTS]

idle to light/mid throttle can be affected by eoit adjustments would be worth checking it out and correct fueling if need be, bucking may be an airmass thing affecting spark see if cleaning up the fueling helps as that changes airflow a little

[kingtal0n]

I use gen3 so its a bit different. But I noticed a HUGE improvement getting the spray away from overlap. I think either before (5.55 stock setting) or way after (6.5 to 6.7) is fine, but nothing in between.

This pic seems accurate based on my experiment result


The engine runs very smooth at 6.5 to 6.7 (just after overlap) no more light shuddering/stumbling when just barely touching the gas.
The fuel smell cleaned WAYYY up. I mean what a relief that was.
And the VE map got richer, most points dropped from 14.9~ to 14.2 to 14.4. So I had to re-tune the VE map.
It also leaned out a little in the load regions which tells me I probably also gained some VE and Torque as well.

Pretty happy to share

[LS ROB]

forgive my ignorance here but are you guys saying that i need to adjust this table here? normal eoit adder vs ect.jpg and if so, what is the process?

[kingtal0n]

I don't know how to do in gen4 but I Can sure help with using search tool

https://forum.hptuners.com/showthrea...highlight=Eoit

https://forum.hptuners.com/showthrea...l=1#post510457

https://forum.hptuners.com/showthrea...l=1#post408545

https://forum.hptuners.com/showthrea...highlight=Eoit

https://forum.hptuners.com/showthrea...highlight=Eoit

[eXo3901]

forgive my ignorance here but are you guys saying that i need to adjust this table here? normal eoit adder vs ect.jpg and if so, what is the process?

I make alot of assumptions in my comments here, but. The Normal ECT table is generally only adjusted in the temp range the vehicle operates in. The stock table has values over 200* in the colder areas and it comes down to 110* in the warmer temps. I think around 154*F the table flat lines at 110* and that carries to the last column. Most leave the cold area of the table stock and only the (stock) 110* values are adjusted and the cam specs dictate how much the values are adjusted.

The Normal RPM table is usually zero'ed out but some people adjust the idle area of this table. I think some stock tables have lower RPM values also.

Boundary is 520 across the board in stock form. This table is the main adjustment when messing with EOI. (EOIT = Boundary - Normal ECT - Normal RPM)

You need to account for how long the injector is shooting its fluid in the motor. So, to do any of this you need to log injector pulse width (and realize on gen4 that logged inj pulse width allegedly does not include the short pulse adder or voltage offset vs. manifold values). Add all those up and use those final total pw values in your calculations. (SOIT = EOIT - PW(in crank degrees))

I am not sure exactly how the Makeup tables play into this but the spreadsheets seem to account for it. Right or wrong, I do not know.

Lots of discussion and multiple spreadsheets on this topic. At the end of the day the gains you might get are minimal and apart from reducing fuel smell at idle, only obvious on a dyno, maybe.

[GHuggins]

I would argue that with my dying breath Boosted applications especially it is a VERY keen player - I have gained up to 120hp with injection timing alone on twin turbo setups below 3000 rpms Not to mention if when done correctly and at a linear retard rate with rpms IT WILL increase torque enough to rip the tires loose whereas it may not have before... Just takes some playing and getting right for the particular application.

Also as far as the ect table goes - depending on cam and setup - you can shift the whole range the same amount or mostly flatline it - you have to watch trims at cold start idle along with some throttle snaps to know where to set it to...

[kingtal0n]

If the EOIT is boundary - ECT then why do you have to change both boundary and ECT, shouldn't just the boundary globally shift everything later and ECT is the same ? I get moving around for ECT but the global shift from boundary does most of the work, no?

[GHuggins]

ECT is the global adder based off of ect if that's how you would like to look at it. Boundary is rpm specific. Then rpm is a finer rpm specific table that ends around 3000 rpms "thinking off the top of my head here". I do not know if the last value at 3000 rpms is carried on throughout the rpm curvature.

[LS ROB]

@kingtal0n- thanks for the links. I went down a rabbit hole and ended up reading about something else.
@eXo3901-thanks for the info. I will have to redo my injection timing as I'm waiting on a response email from TSP for figures @.006. I used .050 which is what I had at the time. it's not correct but an improvement from what I had.
@ghuggins-thanks for dumbing that down for me. it usually takes me a few times to learn something new. ill get cam figures @.006 and give it a go from there.

[LS ROB]

Ghuggins- i tried the settings from that cal. you sent a while back. the pedal felt spongy and had a slight lag. thats when i went on the hunt for the spreadsheet. hoping TSP gets back in touch soon with figures at .006, but if i understand what you were saying in the other thread, (my apologies for thread hopping) i should log a WOT stomp at 540 boundry after some idle time and also at 500? is this to determine the general direction i should go?

[GHuggins]

Yes, that's what your trying to find out. That cal I sent you way back required you to change the stoichio settings too. I imagine you didn't copy those over. It was specifically setup to short circuit fueling a touch to eliminate super sensitive bucking. The one you posted above is not incorrect - just need to bring the curvature down below 4000 rpms. That's if all your after is torque and response. Fuel consumption will however be higher. Typically anyway....

[LS ROB]

injector & itt tune.hpt

i recieved the figures for the cam from TSP and this is the new settings according to the spreadsheet. how does that look? the way i copied the info from the cal you sent was- after i opened the compare file, anything that was highlighted green got copied over including the stoich table. quite possibly, copied over too many settings and it just didnt jive with my setup. however, i didnt have ITT dialed in and that made a noticeable difference for me.

[GHuggins]

Made an ever so slight adjustment for you. If you copied even the injector stuff over then that explains everything. You might even want to retry it with just copying boundary, ect and rpm along with stoichio tables only.

[NotSure]

May I ask why the straight figure across the Normal ECT chart? All of the stock cals that I have looked at have it decreasing as ECT goes up, I assumed to spend more time on the back of the intake valve to vaporize when the engine is cold. I need to do more work on injector timing myself. I left this chart alone as I am still running a stock cam.

[GHuggins]

Depends on the cam and it's corresponding overlap - if advanced in colder temps you can wind up with fuel just going out the exhaust. You have to do wideband and throttle snaps to see what you need to do with it.

[07GTS]

i usually have ect flatlined with ethanol as id rather more in the warming chamber then a cold valve as the ethanol will just be trying to cool it further anyway, and u dont waste as much straight out the exhaust sometimes too

[LS ROB]

i ended up copying the tables over from the cal. from a while back. throttle snap feels good. stood on it in 1st gear and instantly tires lit up, so that makes me happy. however, it did have some "cruise control" feel to it. i figured id need to adjust VVE anyways so i tried tweaking VVE. ill get a log tomorrow after work and see what the results are. Huggins i appreciate the help brother.