More EOIT questions

[ingsteve]

Kyne are you going open loop?
PE mode below 1800rpm?
My cam is smaller but i cannot say it is like stock below 1800...

[Widebody06]

Ingsteve, nice thread on the brake install, I'll be doing that in a month or two.
You should have no problem with open loop and even closed loop- which I run and my PE is 1200.

I seen a lot of experts say get your idle right first then work on the transition. It should go without saying that a car that idles isnt necessarily tuned properly. Lots myths out there like you have to disable PO300 because you cant prevent misfire...bull crap.

I'm a newbie but from what I've seen, if your cam is at or under 300* advertized, .600 lift 11x split you should be able to run stock tune setup...not saying same table values but you dont have to disable anything or put up with the motor not being as drivable as stock or run open loop only or MAFless.

Post up your stuff and let the guys see what you have...dont forget a great tool to figure out what going on is to load the stock tune and use compare to see whats changed.
My tune was done by a shop originally and like many, they just threw a blanket over a lot of table and doubled things....including VE which we all know is backwards for cammed cars to idle.
When you find tables that vary a LOT from stock, see where the low rpm areas take you when you lower them closer to stock.

[ingsteve]

I have some problems below 1800... expecially some time in second gear before a corner it starts bucking a round 900-1200rpm...that was annoying...
I made the tune starting from the stock zone.
I'm in closed loop ve+maf only cover 3600 as per stock tune settings..

[Kyne]

I'm SDCL, I'll try to get some videos of mine driving tomorrow. I have a video on my kyne tuning Facebook page of me driving like 40-45 but not idling in gear like I can do.

[Kyne]

Ok so I tried retarding the ECT again and while it doesn't buck as bad as it used to with a MAF tune and it retarded it isn't nearly as smooth as it is when I advance the table. Cruise control going down hill bucks a lot under 1500rpms and I can't idle in a gear anymore. At school I would put it in 4th and go 20mph with my foot off the gas and now it's bucking bad enough there to make it rough. I'm switching back to my settings. I'm not sure why it works so well with the cars I've done.

[Widebody06]

Perhaps Dave can tell us what the spreadsheet is telling us when you increase the value in ECT...what I see is the area of red cells increase removing cells that otherwise might show white. If I increase all cells significantly, NO cells show white unless I make an equally large change in RPM...like going from 10 to -70. Cant see how a 16 deg change in cam overlap should require a 70 deg shift in injecton timing.

[BBA]

Cant see how a 16 deg change in cam overlap should require a 70 deg shift in injecton timing.

The difference is the small overlap on a stock cam versus the large overlap you now have, may require completely stopping spray on the backside of the valve where the stock cam allowed it.

[Widebody06]

Whatever you're trying to say isnt coming thru...the injector always sprays on the backside. The 70 deg shift is an advance vs a 10 deg retard...Kyne is saying in terms of results the effect is the same for the same cam. I'm asking how that is reflected in the spreadsheet.

[MikeOD]

Ok so I tried retarding the ECT again and while it doesn't buck as bad as it used to with a MAF tune and it retarded it isn't nearly as smooth as it is when I advance the table. Cruise control going down hill bucks a lot under 1500rpms and I can't idle in a gear anymore. At school I would put it in 4th and go 20mph with my foot off the gas and now it's bucking bad enough there to make it rough. I'm switching back to my settings. I'm not sure why it works so well with the cars I've done.

I'm flying home tomorrow and going to screw with this more.

How far do you think I should try to go?

[Michael_D]

I am playing with again..... I have a question regarding injector pulse calculations and the offset adders. My tune file has zero's across the board for Volts vs. MAP. The Offset vs. Press vs. IGNV however is populated with multipliers. Should I ignore these adders? I'm not sure what I would log to find these values.

[Kyne]

That's for the injector data, don't play with it. And mike I just keep adding until it smooths out. I'm not sure what to go to.

[Michael_D]

Yes I know. I'm using Dave's worksheet and need to input injector pulse width. I have multipliers in the injector offset tab > Injector Offset vs. Battery Voltage vs. KPA VAC. I do not have any multipliers in the other offset table that Dave mentions below (Bat Volt vs MAP), all cells have zeros in them.

The Offset table description reads: Injector Offset vs. Pressure Delta vs. IGNV: This value is added to the injector pulse width as the delay time it takes for the injector to operate. It varies with the pressure across the injectors and battery voltage."

I do not know what I can log to determine the "pressure delta across the injector".

Blue cells represent cells you can edit. For the Boundary, set it to the same number across the board. Crank Duration and Target EOI are values that are calculated.

In the table with ECT and RPM as axis labels, red cells mean you're ending EOI too early and will possibly fire while the exhaust valve is open. Green cells mean you're behind the exhaust valve closing. White means you're dead on. It is advised to use 0.006" lift values instead of 0.050" lift values.

Play with the blue cells to find your final values. I'd suggest not changing the boundary.

Also, note that pulsewidth is the fuel injector pulse width taken from the scanner plus the short pulse adder and voltage offset. You need to manually look these up. If your idle pulse is 1.0ms for example, go into your tune and look up the short pulse adder at 1.0ms. Add that to the pulse. Then, look at your battery voltage and MAP value. Go into the voltage offset and look that up, and add it to the pulse. 2.2ms is the final delivered pulse on my car with my ID1000s while idling at 800rpm.

I said there was nothing special. It's pretty simple and plain!

[Michael_D]

Found it. PID>Fuel System>Fuel Pressure>Inj Delta Pressure

It varies between 2.6 and 3.2 at steady rpm, and I do not have the patience to chase it all over the damn place, so I'm calling it 3.

So after playing around with EOIT with more effort yesterday, than I put into it last year, I've successfully made the 1500 - 2000 rpm low load cruise surging worse. When taking the time to really pin down a calculated crank degree and when to shoot fuel after the exhaust vlv is shut, many Normal RPM target numbers were negative. Some more than -30. (These are the targets found in the Normal EOI Target vs. RPM table). When inputting a negative value in the cells, the cells turn a bright angry red, so I figured that was most likely, not a good idea. I then lowered the ECT table cell 20 degrees. With these cells lowered, I then had to add a few degrees to the cells in the Normal RPM table.

I'm running a blended MAF/VE tune, with MAF taking over at 1500 rpm. Fueling is in the weeds under 1500 rpm now, with LTFT's running about +10. They were all under 4. So it's pretty clear this definitely changes fueling. Now it's a matter of figuring out which direction to go. (the cam I'm running in an LS7 has 73 deg seat to seat overlap).

[DSteck]

You're all nuts.

The spreadsheet was meant purely as a visual to show end of injection in relation to the exhaust valve closing. The colors mean nothing. They're just what I chose because that's how a lot of HPT histograms are set up. There's no law that says magic things happen when you match up EOIT with the exhaust valve closing. The only thing I've found is that matching them at idle minimizes smell.

Don't overthink this and don't assume it does more than it actually does.

[Widebody06]

Which is exactly why I asked what does all this mean
And the answer is tunings is an experimental process aided by experience, newbies like myself are in deep water if you want to do more than tune for WOT performance.

[Michael_D]

You're all nuts.

The spreadsheet was meant purely as a visual to show end of injection in relation to the exhaust valve closing. The colors mean nothing. They're just what I chose because that's how a lot of HPT histograms are set up. There's no law that says magic things happen when you match up EOIT with the exhaust valve closing. The only thing I've found is that matching them at idle minimizes smell.

Don't overthink this and don't assume it does more than it actually does.

Oh stop being so snarky.

If you're referring to my comments on color changes, then you didn't read my post correctly. I couldn't care less about the color change in your worksheet, although it is a neat trick. I was referring to the cells in the HPT table. They did not like a negative number.

Moving the fuel shot later in the stroke makes sense when you change valve events with a larger camshaft. Whether or not it will help eliminate surging is debatable, but worth experimentation. I spent a few hours messing around with yesterday, and things are looking better.

[DSteck]

It's not directed at anyone in particular. I just keep seeing people assume things that aren't there.

It's a visual, and is meant to build in the calculation to convert pulse width to crank degrees at a given rpm.

[Sébast19X]

Oh stop being so snarky.

If you're referring to my comments on color changes, then you didn't read my post correctly. I couldn't care less about the color change in your worksheet, although it is a neat trick. I was referring to the cells in the HPT table. They did not like a negative number.

Moving the fuel shot later in the stroke makes sense when you change valve events with a larger camshaft. Whether or not it will help eliminate surging is debatable, but worth experimentation. I spent a few hours messing around with yesterday, and things are looking better.

So in end , have you lowered the number or increased it vs the stock table to get a better ride ?

[Michael_D]

Well I'm still screwing around with it... Right in the middle of my next "experiment", it started to rain like a cow pissing on a flat rock...

But in the end, I had to lower the Normal ECT numbers from 110 to 90, AND move the targets in the Normal RPM table to move toward the calculated target (some up, some down). With the cam I am running now, the .006 EVC event is 39 deg ATDC. If I leave the ECT values stock, and I want to shoot fuel after the valve shuts, some values were negative. When I lower the ECT values 20 degree, I do not have to enter a negative value in the HPT normal RPM table. It is an iterative process and the worksheet is an excellent tool to see what the piston position is in relation to valve closure. Granted, it is not perfect, but a damn good reference tool. So anyway, I am working my way towards the target, slowly... MAF LTFT's did not move, and I didn't expect them to. But VE LTFT's did, significantly. I had to re-calibrate VE table under about 2000 rpm.

If nothing else, it's worth playing with the worksheet and see the effect a change makes. Kinda cool really, and there's a pretty good chance someone might learn something.

[Widebody06]

Michael, how sure are you about that 39 deg? thats 31 deg more than mine. I'd have to say, if you're right, my 6 deg is wrong and I need to contact Trick Flow