help with eoit tuning

[dhoagland]

ethanol percent is a set stoich for the burn so should be left as is stoich table, if ur having to adjust that then its prob more so injector data is off a smidge

Thanks for the response, I appreciate it.

My sensor reads 5% different (more) than what the actual content is.
So when running Ethanol free (and confirmed with a kit) my sensor registered 5% not zero. This caused my commanded AFR to be around 14.25 (following the stoich table [ECM12300] as it should) instead of the 14.67822 as should have been commanded by the same table (and I'm sure it would have if the sensor reported Zero).

I adjusted [ECM12300] to command 14.6 when my sensor reads 5% ethanol content (actual content is zero, but sensor won't go lower than 5%).

I hope I'm explaining this correctly.
My commanded AFR is now what it should with the offset I put into the table regardless of what the sensor reports.
E-0 commands 14.6
E-10 commands 14.1

I'm going to test some higher percentages to see if the offset is linear

So when I run across someone with a sensor fitted vehicle I ask if the have verified their sensor.
If most people have no error with ethanol free, I'll replace my sensor

[07GTS]

did u test the sensor outside the vehicle flushed out and dry ? sounds like the sensor is an issue then as it should read 0, did u get the sensor with the temp offset built in ? they can get affected by that sometimes if the fuel is heating up too much, i done a test with mine once on petrol with engine idling i kept it super low and added ethanol and watched it adjust as it filled up and stayed within a few percent over a 50% ethanol shift and settled when done, can still be some in the system and take a few tanks of petrol to remove it unless they are sneaking e10 into it without saying at the bowser

[Knight123455]

can you keep the the normal rpm table as is. just trying to understand why you zero this out. I set mine to 520-normal ect in the 110 area lowered to 80 and seems alot better. this is a gen 4 z06 with HCI BTR3 cam. Thanks in advance.

[turabo87]

I stumbled on it from a previous thread but this is the technique that works for me and makes actual sense to me, especially to reduce the smell of unburned fuel for larger cam in idle. Get specs of stock cam and specs of new cam: intake and exhaust duration, LSA, intake centerline. Put them in the Wallace Racing cam degree calculator http://wallaceracing.com/cam-deg-calc.php (if you use advertised duration, use it for both cams. If you use [email protected], then use it for both cams), and get the EVC for both cams (stock and the new one). The DIFFERENCE between the two EVC (say stock cam EVC is -11.0deg ATDC and new cam EVC is -1.0deg ATDC), whatever that difference is you add it across the board to the boundary table. In this example it would've been adding 10 to the entire boundary table. The logic here is that you want to shift EOI target boundary by the same amount that the EVC shifted forward by, to avoid "short circuiting" the fuel straight from the intake thru the exhaust if the exhaust valve hasn't closed yet (based on the shift of EVC).

I've done this technique in multiple cammed cars and reduced smell at idle by over 50%. The beauty here is that there's no guessing either. Just shift it by whatever the math says to do it by.

[Knight123455]

Than you, ill apply this and see what i get. With the current settings my LTFT are + 1.6-2.0 at cruise and -4.7 at idle. I have adjusted the MAF hertz in the mentioned area to see if the fuel trims get back to zero, haven't drove yet. like I said I will apply your approach and see if this helps. Thank you again for your time.

[GHuggins]

Don't forget about rich after flash - will skew a lot of your progression. All cams are different and will require different settings depending on the rest of the engine build. Your engine may actually want it advanced, so don't be afraid to try different settings.

[07GTS]

can you keep the the normal rpm table as is. just trying to understand why you zero this out. I set mine to 520-normal ect in the 110 area lowered to 80 and seems alot better. this is a gen 4 z06 with HCI BTR3 cam. Thanks in advance.

u dont need to advance the injection as rpm increases so the normal rpm is zeroed out, with the boundary at 520 after u have found the sweet spot lowering the normal ect u can use boundary to play with it as the rpm increase which takes the function from the normal rpm table anyway, normal ect advances injection added to boundary value before the boundary, boundary value higher delays injection, just dont delay too far u dont want to catch the reverb out the intake valve before it closes

[Knight123455]

sorry I worked 14 hrs yesterday. So I used the stock cam specs 211/230/120/3= -122 and btr3 237/250/113/3= -98. is this correct if so i would add 24 across the boundary table and zero normal rpm. also I am aware of the rich after flash and thanks for asking that question as it does make a difference when tuning.

[[email protected]]

u dont need to advance the injection as rpm increases so the normal rpm is zeroed out, with the boundary at 520 after u have found the sweet spot lowering the normal ect u can use boundary to play with it as the rpm increase which takes the function from the normal rpm table anyway, normal ect advances injection added to boundary value before the boundary, boundary value higher delays injection, just dont delay too far u dont want to catch the reverb out the intake valve before it closes

Hello 07GTS I have followed the instructions you gave me awhile back which are the same as you stated in this post. I have struggled with finding the sweet spot. My cam data indicates the EVC is 397 deg ATDC on the 720 wheel. That leaves 123deg window at idle between 397 and 520. PW at 800 rpm is 2.7 or 12.9 to 13 deg. Makeup ECT was lowered to 25 per instructions, so should SOIT target should be in the 397deg range? If so then Normal ECT would be 123-(25+13)= 85 or in that range. I am having a problem starting at Normal ETC of 110 and lowering. After each flash, I reset the LTFT's and wait but the trims usually return to same all the way to 85 and lower. Should I make a WOT pull between flashes also? Should I open and close the throttle 10 times as suggested in Hyme's idle tuning tutorial.? What am I doing wrong?

[GHuggins]

If you really want to go "in depth"... Members on here made this up some years ago.

[07GTS]

Hello 07GTS I have followed the instructions you gave me awhile back which are the same as you stated in this post. I have struggled with finding the sweet spot. My cam data indicates the EVC is 397 deg ATDC on the 720 wheel. That leaves 123deg window at idle between 397 and 520. PW at 800 rpm is 2.7 or 12.9 to 13 deg. Makeup ECT was lowered to 25 per instructions, so should SOIT target should be in the 397deg range? If so then Normal ECT would be 123-(25+13)= 85 or in that range. I am having a problem starting at Normal ETC of 110 and lowering. After each flash, I reset the LTFT's and wait but the trims usually return to same all the way to 85 and lower. Should I make a WOT pull between flashes also? Should I open and close the throttle 10 times as suggested in Hyme's idle tuning tutorial.? What am I doing wrong?

i dont worry too much about SOIT it will be what it will be as were port injection so have plenty of time, i only think of moving it around to see what works best as the airflow going in is a back/forth motion its not one way so if u find a good inward pulse to inject on it will work well so just trial and error see what works best for yours, as mentioned by GHuggins even going the other way can work well in some, if u want more stable results u can go for a 15 min drive just so everything gets up to temp so any changes are more noticeable if the adjustment works, or maby the overlap is working to get it in the cylinder at lower speeds and not as much out the exhaust, the calculators are good to see whats expected to happen but have to leave some room for error mechanical wise in the engine

[pannetron]

Did you set the injector off time to zero?
Table [ECM 45524]

What's the need or desire to set this to zero vs a non-zero number in an OEM tune?

[Knight123455]

I noticed when I used the injection tool spread sheet that the #'s that I would add to the EOIT boundary are almost the same as what I would delete from the normal RPM table. has anyone else noticed this and if so please comment. I am trying to get this last part sorted out in my tune.

thanks for the help.

[legerwn]

07GTS, does your method work with VVT cams?

[GHuggins]

I noticed when I used the injection tool spread sheet that the #'s that I would add to the EOIT boundary are almost the same as what I would delete from the normal RPM table. has anyone else noticed this and if so please comment. I am trying to get this last part sorted out in my tune.

thanks for the help.

RPM numbers advance the timing with increasing / ect numbers advance the timing with increasing / boundary numbers retard with increasing their numbers

[[email protected]]

i dont worry too much about SOIT it will be what it will be as were port injection so have plenty of time, i only think of moving it around to see what works best as the airflow going in is a back/forth motion its not one way so if u find a good inward pulse to inject on it will work well so just trial and error see what works best for yours, as mentioned by GHuggins even going the other way can work well in some, if u want more stable results u can go for a 15 min drive just so everything gets up to temp so any changes are more noticeable if the adjustment works, or maby the overlap is working to get it in the cylinder at lower speeds and not as much out the exhaust, the calculators are good to see whats expected to happen but have to leave some room for error mechanical wise in the engine

I have tried 07GTS's method and could not see the a richer mixture at idle. I have tried the Inj Timing Tool method with similar results. What has worked so far is to add the Delta of New vs Stock Cam IV opening and add that to Normal ETC. The fuel at idle has finally gotten richer. I'm going to keep trying to determine if adjusting the fueling is going to help.

[GHuggins]

Sounds like your cam may like advanced injection timing then. Keep in mind you need to adjust for startup, idle control and drivability all in one... The timing will effect everything.


On a side note - the tool isn't for changing your numbers for you. Just to let you see what changes you make to the numbers actually does in relation to valve overlap and so on.

[07GTS]

07GTS, does your method work with VVT cams?

ive not worked with VVT cams but u can try it just move the ect around to where it likes it the most, once ur above sorta 3k rpm most cams overlap event should be doing its job and getting more into the chamber its just the lower rpm that can benefit

[blkchevyz]

I stumbled on it from a previous thread but this is the technique that works for me and makes actual sense to me, especially to reduce the smell of unburned fuel for larger cam in idle. Get specs of stock cam and specs of new cam: intake and exhaust duration, LSA, intake centerline. Put them in the Wallace Racing cam degree calculator http://wallaceracing.com/cam-deg-calc.php (if you use advertised duration, use it for both cams. If you use [email protected], then use it for both cams), and get the EVC for both cams (stock and the new one). The DIFFERENCE between the two EVC (say stock cam EVC is -11.0deg ATDC and new cam EVC is -1.0deg ATDC), whatever that difference is you add it across the board to the boundary table. In this example it would've been adding 10 to the entire boundary table. The logic here is that you want to shift EOI target boundary by the same amount that the EVC shifted forward by, to avoid "short circuiting" the fuel straight from the intake thru the exhaust if the exhaust valve hasn't closed yet (based on the shift of EVC).

I've done this technique in multiple cammed cars and reduced smell at idle by over 50%. The beauty here is that there's no guessing either. Just shift it by whatever the math says to do it by.

i know this is old, but with that math, say my stock cam is -12 and my new cam is 5. so would i subtract 7? since the number is -7 or would i still add?

[pannetron]

The difference in crankshaft degrees is actually 17 given your numbers. With a 215/247 @ 0.050" 121 LSA cam, here's the injection boundary table I ended up with to minimize idle exhaust smell:

2022-09-30_14-40-37.jpg

And my wife still hates the smell!