dtaforum.psycode.com

Astra4wd · Joined: 24 Feb 2007 Posts: 42

Stevieturbo: thanks for leading me into the correct path.
i was 'locked' in mind that this low values were bad.

now i got:
25
10
0

Now it makes MUCH more small adjustments and wait´s a longer time before adjusting again.
now i just have to tune 'throttle to lock' for a bit.

when revving up and the engine drops in rpm back at idle, it adjustes it a little bit lean, down to Lambda 1.1, and engine makes small hickups there so it´s close to stall.

stevieturbo · Posted: Sun Feb 07, 2010 12:07 pm Post subject:

The other numbers may have been fine. Although a sample rate of 1 per sec is probably too slow.

Leave closed loop off, and record lambda on the PC as Ive already stated to do many times.

it works better.
_________________
383 LS1, YSi

9.85 @ 144.75mph
198.3mph over 7/8th mile logged by me.
http://www.youtube.com/watch?v=XgWRCDtiTQ0

Astra4wd · Joined: 24 Feb 2007 Posts: 42

haha.. i wrote that i was about to alter the samplerate, but i changed my mind so i deleted it in the last post before posting it.

yes it might work nicer with direct recording.
but i want to get some kind of mileage on fuel also when running E85 fuel.

and when cruising it adjust´s itself a little if the fuelling is off.
when having bad vaccum and map as load the mappoints alter a little
One day you run lean, the other day you run rich without having touched the map.

stevieturbo · Posted: Sun Feb 07, 2010 12:45 pm Post subject:

Really, unless there are other problems with the mapping. You should be able to drive all day every day, and see very consistent AFR's everywhere.

If you are seeing big differences for no apparent reason, you have problems elsewhere.

its not like weather and conditions vary over here so much, or altitude etc.
_________________
383 LS1, YSi

9.85 @ 144.75mph
198.3mph over 7/8th mile logged by me.
http://www.youtube.com/watch?v=XgWRCDtiTQ0

Astra4wd · Joined: 24 Feb 2007 Posts: 42

i knew you´d say that.

but i got this big injectors and they are a little bit unstable at low openingtimes.
so even if voltage alters a bit in car when lightening the headlights for example it makes difference.

and i have set a table for deadtime to overcome this problem.
it helped, but not perfect.

and a moisty day the alternator for some reason gives higher voltage.
normal with Delco alternator in Vauxhalls.

stevieturbo · Posted: Sun Feb 07, 2010 2:35 pm Post subject:

so you need to get a proper voltage compensation table for your injectors then ?

Send them away to a company who can do this for you.

Or else purchase a voltage regulator/stabilisor and supply the injectors or other critical items from this, so they always ensure the same voltage.
_________________
383 LS1, YSi

9.85 @ 144.75mph
198.3mph over 7/8th mile logged by me.
http://www.youtube.com/watch?v=XgWRCDtiTQ0

Astra4wd · Joined: 24 Feb 2007 Posts: 42

This was just an example of what can modify the AFR with out having the EMS to do it.(outer factors are many, the world is much more dynamic than an cheapo EMS can handle)

I´m not givinvg closed loop up!

stevieturbo · Posted: Sun Feb 07, 2010 4:41 pm Post subject:

It is a pity it wasnt easier to get the settings optimised better.

I see little reason why the ecu couldnt self determine the best settings for closed loop operation.

I think I had mine at 4 samples per sec, then 70,30,10 although I only allowed -3% and + 8% adjustment when I used it.

Although I use a different make of wideband controller.

One annoyance is...unless that has changed. It used to be the three numbers had to add up to 100. Clearly something somewhere has changed, given you can now input values up to 1000 in each box.

There has never been any reference to this change in any manuals as far as I have seen.
_________________
383 LS1, YSi

9.85 @ 144.75mph
198.3mph over 7/8th mile logged by me.
http://www.youtube.com/watch?v=XgWRCDtiTQ0

The Zedhed · Posted: Mon Feb 08, 2010 10:49 am Post subject:

The manual still states they should add up to 100 Rolling Eyes

_________________
Things will always get faster,
When I pull me finger out and build it..........!

kevhaywire · Joined: 13 Mar 2007 Posts: 479

Yeah, and I've noticed a few other references to the old P8 still in the S Series manual. And even though it said they had to add up to 100, the P8 still let you leave one of the PIDs empty.

I used to use 50, 5, 0 in my old P8, but after migrating the map over to the S80, I found the closed loop did practically nothing. I had to increase it to 500, 50, 0.

I too find the lambda drifts from one day to next. I don't really consider it a major problem as I've watched OE management vary the lambda trimming differently from one day to the next. I guess some engines are more sensitive to external changes than others.

The thing that upsets my fuelling the most is battery voltage. Not so much the injectors as I use the compensation table (the injectors were professionally IDT tested from 8 to 16V) and it works OK, but it's the MAP sensor which seems more sensitive to voltage fluctuations.

I also use an idle valve and that will definitely influence the Idle AFRs from one day to the next.

Personally speaking, I find DTA's lambda control to be incomplete and too slow, but working with what we've got, I can get it to an acceptable compromise, but it could be better.
_________________
VR6 turbo powered by DTA S80

stevieturbo · Posted: Mon Feb 08, 2010 12:56 pm Post subject:

If its wired right, it would be impossible for MAP sensor voltage problems unless you have a faulty map sensor, or signal line

Its fed along with all other sensors from a regulated 5v, regardless of what voltage the ecu sees. These sensors always see a steady 5v.
_________________
383 LS1, YSi

9.85 @ 144.75mph
198.3mph over 7/8th mile logged by me.
http://www.youtube.com/watch?v=XgWRCDtiTQ0

kevhaywire · Joined: 13 Mar 2007 Posts: 479

Cheers Stevie. You're right, I checked the 5V supply and it shows a constant 5009mv in the diagnostic screen.

I guess I have other issues then!

Maybe it's just down to the winter blues and the alternator is constantly damp etc, not sure!
_________________
VR6 turbo powered by DTA S80

stevieturbo · Posted: Thu Feb 11, 2010 5:43 am Post subject:

When you say MAP signal fluctuates....is the signal line damped at all ? where is the takeoff ?
_________________
383 LS1, YSi

9.85 @ 144.75mph
198.3mph over 7/8th mile logged by me.
http://www.youtube.com/watch?v=XgWRCDtiTQ0

kevhaywire · Joined: 13 Mar 2007 Posts: 479

The MAP sensor is the Bosch 4 bar / air temp one DTA sell, which is mounted directly to the intake manifold.

Not sure what you mean by damped. Do you mean the filter value in the Sensor scaling settings?

I might go back to my old GM 3 bar on a 12" pig tail and see if matters improve.

For 3 years now I've had massive boost spikes showing in the diagnostic screen. My wastegate is set to 190kpa and 99% of the time, that's what is shown as a max in the diag page, but every now and then, it will show something daft like 400kpa and the overboost time is 0.00 seconds.
Very odd. Electrical noise perhaps? Is that what the filter does?
_________________
VR6 turbo powered by DTA S80

stevieturbo · Posted: Thu Feb 11, 2010 2:34 pm Post subject:

By damped, I mean just that.

ALthough if the sensor is mounted in a wide open plenum, I assume that would provide adequate damping over say a single takeoff from a single runner, which woul;d be a bad location.

A damper would be a small orifice in the signal line ( carb jet or similar )

I guess in theory, the electronic filtering would do the same thing though. I havent had to use it myself though. But Ive always used remote map sensors.

If you are seeing random spikes, high or low, or just erratic voltage traces. Then maybe it does need more filtering. Or perhaps it is reading a mechanical problem ??

I guess a small backfire could show as a boost spike. Say intake valve not closing etc ?
_________________
383 LS1, YSi

9.85 @ 144.75mph
198.3mph over 7/8th mile logged by me.
http://www.youtube.com/watch?v=XgWRCDtiTQ0