DFCO table questions

[QUICKSILVER2002]

The DFCO tables are a bit confusing to me. I know what DFCO is all about, but the tables are a bit confusing to me.

Can somone explain the DFCO MAP table? It has the rows 60,70,80,90,100 kPa. And then it has two editable colums that are also listed as kPa.

What the heck does the 60...100 represent. Is it the atmospheric pressure?

The DFCO Thottle Enable table is also strange. I see values like 1.5 @ 3600Rpms and it says that the throttle position muse be below this value to enable DFCO, yet I never see tp values that low. Is that a relative TP (above the IAC).

The m6 parameter values also seem to make no sense. B3312 = 321 (Vehicle speed muse be above this to alow DFCO M6 to occur). Does it just ignore this stuff or what? Is DFCO m6 something different than regular DFCO on an M6 car?

[oztracktuning]

Good questions here - im interested in some of the answers too!

[GMPX]

What the heck does the 60...100 represent. Is it the atmospheric pressure? Yes, it should show on that axis "Baro kPa' (or whatever units you use), it is showing here fine on my PC.



The DFCO Thottle Enable table is also strange. I see values like 1.5 @ 3600Rpms and it says that the throttle position muse be below this value to enable DFCO, yet I never see tp values that low. Is that a relative TP (above the IAC). It is based on the 'real' TP values.



The m6 parameter values also seem to make no sense. B3312 = 321 (Vehicle speed muse be above this to alow DFCO M6 to occur). Does it just ignore this stuff or what? Is DFCO m6 something different than regular DFCO on an M6 car? DFCO is used when changing the gears, it is different to the normal DFCO that is used when coasting down a hill etc.

Cheers.
Ross

[TAQuickness]

I had to do some minor tweaking to DFCO to realize it's worth with my cam.

[GMPX]

Getting DFCO in earlier than the factory settings is the best way to pick up some MPG......way better than Lean Cruise.

Cheers,
Ross

[TAQuickness]

Getting DFCO in earlier than the factory settings is the best way to pick up some MPG......way better than Lean Cruise.

Cheers,
Ross


indeed. Makes for killer engine braking too.

[oztracktuning]

I am amazed that on most forums and in many workshop tunes i know of people have it turned off.

DFCO being functional as much as possible is not going to do any damage is it.

Also what effect would there be of different timing levels during DFCO?

Mine is currently set to activate above 1100rpm and stay in DFCO until 875rpm and entry below 38 and exit at 46map at less than 0.7% throttle.

I have also bumped up the entry speed to the base spark table to 80kph so that i dont have trouble with spikes in rpm with my converter when off the throttle and not in DFCO.

Nice to somehow set the car up so that everytime im off the gas no gas is being used.

[ringram]

Its good to leave dfco disabled in top gear, so you can coast down hills on the motorway etc without decelerating and having to waste fuel to get back up to speed.
I used it on the first 5 gears as per factory, but get it to come on immediately when no throttle is used.

Also means you can use the brakes less, as TAQuickness says its good for engine braking. You can drive using the throttle a lot more of the time.

[oztracktuning]

I have an Auto so DFCO usually only comes on in top gear.

Would adjusting the timing have any effect on engine braking? Is it safe for the engine to adjust this at all.

[joecar]

See B3336.

[oztracktuning]

OK so how long does it take to arrive at the DFCO timing level. Im not sure my car is doing this that well. Its showing 0.4% throttle minimum and im not sure if thats preventing the DFCO timing happening or does it take a while to arrive??

Looking more at the logs it looks OK - but i have just changed the Base Spark table to happen earlier at below 80kph - this may make it a bit smoother when it switches in and out of DFCO.

Can i set DFCO to happen straight away just by having the delay as 0 - setting B3307 ??

[Tordne]

OK so how long does it take to arrive at the DFCO timing level. Im not sure my car is doing this that well. Its showing 0.4% throttle minimum and im not sure if thats preventing the DFCO timing happening or does it take a while to arrive??

I find that the timing gets progressively retarded down to the timing defined in the B3336 table. Also check the B3334 and B3335 tables as they also relate to DFCO timing.

With your TP showing 0.4% is it possible that you need to perform a TPS reset? Have you changed the position of the TB set screw at all?


Looking more at the logs it looks OK - but i have just changed the Base Spark table to happen earlier at below 80kph - this may make it a bit smoother when it switches in and out of DFCO.

Can i set DFCO to happen straight away just by having the delay as 0 - setting B3307 ??

The B3307 value defines the timeout required to allow DFCO to re-enable after DFCO has been disable. For example if this value was 2 then if DFCO had just disabled through a throttle application and then you backed off again. 2 seconds would still have to pass before DFCO would become enabled again, even though all the DFCO enablers are meet.

[oztracktuning]

Just had someone on another board share with me that are using settings that effectively give DFCO every time they are off the throttle.

rpm entry 610 and exit 611 rpm (stall rpm 680) car idles at 600rpm stock cam
Map anything under 80 kpa
speed 1 kph


This would have to save a heap of fuel.

[oztracktuning]

I will try resetting the TPS sensor - i thought i did it once before.
Its just disconnect - turn key on leave it on for a little while - turn it off - then reconnect and turn it on again. It should reset - is this right??

[Tordne]

Just had someone on another board share with me that are using settings that effectively give DFCO every time they are off the throttle.

rpm entry 610 and exit 611 rpm (stall rpm 680) car idles at 600rpm stock cam
Map anything under 80 kpa
speed 1 kph


This would have to save a heap of fuel.

Those are some serious settings!! I'd be interested to see who that feels to drive, especially when like approaching speed humps in second gear (M6). I found that if you exit DFCO at the wrong time it lurches a bit.


I will try resetting the TPS sensor - i thought i did it once before.
Its just disconnect - turn key on leave it on for a little while - turn it off - then reconnect and turn it on again. It should reset - is this right??

Yup,
1) Disconnect TPS sensor
2) Turn ignition key ON, DO NOT START CAR.
3) Leave key on for 30 seconds
4) Key off
5) Reconnect sensor
6) Not sure if you need to leave 30 seconds before starting

[TAQuickness]

Those are some serious settings!! I'd be interested to see who that feels to drive, especially when like approaching speed humps in second gear (M6). I found that if you exit DFCO at the wrong time it lurches a bit.



Yup,
1) Disconnect TPS sensor
2) Turn ignition key ON, DO NOT START CAR.
3) Leave key on for 30 seconds
4) Key off
5) Reconnect sensor
6) Not sure if you need to leave 30 seconds before starting

I think 15 seconds will do, but I'd wait 30 to be on the safe side ;)

[oztracktuning]

Bumping up the speed of entry to Base Spark seemed to stop DFCO timing from happening. So i have dropped it down again quite low. Will see tommorrow if i get low timing again in DFCO.

I hope this is what caused the problem ??

[oztracktuning]

The DFCO Spark in some newer tunes is
-1.494141
-1.362305
-1.164551
-1.010742
-0.791016
0.000000
1.999512
3.999023
5.998535
7.800293
9.008789
9.777832
9.997559
9.997559
9.997559
9.997559
9.997559
9.997559
9.997559
9.997559
9.997559

In older tunes it might be

0.000000
0.000000
0.000000
0.000000
1.999512
1.999512
1.999512
3.999023
5.998535
7.998047
9.008789
9.008789
9.008789
9.008789
9.008789
9.008789
9.008789
9.008789
9.008789
9.008789
9.008789

What would be the the difference in the way either of these sets of values effects the car??