1.6turbokid

I figured it out. For some reason I had the parameter cut fuel on decelerate to go off at 40kpa but my idle is 26 kpa. I changed the number to 22 kpa and then changed the tps parameter to .3 instead of 1 and everything smoothed out. This was previously masked by having my 5v and signal wire crossed and my car was always out of parameter thinking i was at 20% throttle at idle.

ChrisLol

FWIW I just skimmed this thread but I wanted to mention that the dead time sheet included with my DW700's was WAY off by about half. Since my base fuel was tune'd up pretty well on stock injectors (50ish VE at Idle and 100ish VE at WOT) I turned off O2 Control (closed loop fuel) and added time to the dead times until I got to the idle target AFR.

Full disclosure: I am not using an MS so some of the terminology I just used may be different from what you know.

1.6turbokid

What I ended up doing was keeping the deadtime as advertised and increasing my ve table. This caused my minimum to be ~85 and my maximum to be about ~120 (these are off my head because i am at work) Would having my ve numbers that high cause an issue? Would this cause my injectors to be at a higher duty cycle than if they were lower numbers? Right now my highest duty cycle at about 16 psi was 72% i believe running e85 on a t28 from an s14 silvia.

curly

iTrader: (25)

That's why I like using the correct dead time and modifying the fuel table accordingly. Because if you do it the way Chrislol suggested, I think the duty cycle calculations will be off.

But no, there's nothing wrong with using higher VE numbers as long as required fuel and dead time are correct.

ChrisLol

When using speed density to calculate for Mass Flow, you should not end with VE numbers higher than 100%.

Dead times can vary based on ECU/transistor used to trigger them. In my case, the manufacturer listed dead times were not accurate for my particular ECU/transistor.
It's not that the dead times given were "wrong", or that mine are "wrong", they are just simply incorrect for the application.

sixshooter

iTrader: (12)

100% volumetric efficiency is theoretically perfect at naturally aspirated wide open throttle. Going into boost can take you above 100% volumetric efficiency.

ChrisLol

Eh.

The VE calculation IN ECU is boost compensated. Therefore VE% above 100% are incorrect values.

(edit: when using speed density to estimate airflow)

sixshooter

iTrader: (12)

So the ve table is not actually volumetric efficiency. Got it.

So if you set up your table where your Ve is 100 at its very highest point possible and then turn around and raise your maximum boost allowable due to making other changes you have to throw everything out because it will be over 100? Sounds like a crappy design.

I guess instead of ve they should call it fuel load in the same way timing is ignition load.

ChrisLol

Any ECU using speed density to calculate mass air flow for use in the VE formula will have this caveat. It's not a crappy design, It's just breaking your expectation of the VE output % by introducing the pressure variable earlier in the equation. The end result is the same.

Now if this gentleman's particular ECU is relying on a MAF signal for mass air flow then numbers above 100% should be valid. I've never worked with a system like that. The latest tech uses a MAP and speed density. MAFs are so 1990's.

1.6turbokid

I not using MAF lol. I think I should change my dead times from .715 to 1.4 based on research from other threads using the same injectors. The weird thing is that other data from the same company states to use 1.4 and the data provided to me states to use .715. I have some values as high as 140 up at my 220 kpa ranges so that definetly seems to be an issue based on what you are saying.

Please see conflicting information below:
On the left is 2018 data and on the right is 2014 data but with same part numbers. (my injectors also look identical btw)