Severe lungeing at carpark

[Dose Pipe Sutututu]

4 hours ago, ChrisW434 said:

the initial generic figures are much different to your displayed ones.

Yeah it's a self learning table, also requires your primary fuel table to be decent (with in reason)

[ChrisW434]

9 hours ago, Dose Pipe Sutututu said:

Yeah it's a self learning table, also requires your primary fuel table to be decent (with in reason)

Yep, sounds good. I suspected that to be the case. I'll be able to drive the car late this week, so looking forward to loading up some fresh data and testing it

[Dose Pipe Sutututu]

Here's a funny joke, so got my laptop back from Lenovo after 3x weeks, and literally after one day of use, it's dead again 🥲

[ChrisW434]

1 minute ago, Dose Pipe Sutututu said:

Here's a funny joke, so got my laptop back from Lenovo after 3x weeks, and literally after one day of use, it's dead again 🥲

Great service!

[MBS206]

50 minutes ago, Dose Pipe Sutututu said:

Here's a funny joke, so got my laptop back from Lenovo after 3x weeks, and literally after one day of use, it's dead again 🥲

Is the laptop the problem, or something youre plugging into it killing it?

[Dose Pipe Sutututu]

1 hour ago, MBS206 said:

Is the laptop the problem, or something youre plugging into it killing it?

Not sure?

The same Lenovo USB-C dock is shared with a Thinkbook and T490S as well. It's in the study so either my wife plugs her laptop in, or I plug my work or personal one (Yoga 7i).

Can't be the dock, as the other laptops are still fine.

[ChrisW434]

On 23/8/2024 at 4:13 PM, Dose Pipe Sutututu said:

Got my laptop back after 3x fking weeks at Lenovo... pricks.

Anyhow, here are some screenshots of my tune and how I've calibrated my shit box.

This is the best thing to come out on the Haltech since sliced bread:

 

If you make all this say 15 instead of 12 or whatever so there's not a big timing jump between 950 to 1000 the idle won't "brap" as much. I did this because I am a poser

 

Decel, I find adding in heaps of fuel on recovery stops the idle being aids

 

Also defining fuel density vs. ethanol percentage vs. fuel temperature immensely improved the car's driveability 

 

 

Ok, so i've uploaded the changes i made during the week to the car (MAP prediction, LTFT, a few other things).  
First thing was drivability (on-off throttle in light traffic, roundabouts etc) was very improved.

i am experimenting with turning off/on the decel fuel cut. See how that goes, it drives awesome on/off throttle at cruise speeds as its not jerky when constantly fueling.

The most annoying hurdle i have atm is the idle staying about 300rpm high when i roll to a stop, hanging high for ages, or until i touch the throttle. Not sure what this could be, something to do with closed loop interfering due to a bad setting?

And some jerkiness is still there as the car slows to a slow roll... smoother idle has helped i think

[Dose Pipe Sutututu]

15 minutes ago, ChrisW434 said:

atm is the idle staying about 300rpm high when i roll to a stop,

Try lower the base duty cycle on for your idle table.

 

Also check if your TPS is calibrated properly (don't follow the OEM guide, just go into calibrate TPS in the Haltech settings menu and follow the 2x step procedure) if not the ECU will not enter idle state properly 

[ChrisW434]

5 minutes ago, Dose Pipe Sutututu said:

Try lower the base duty cycle on for your idle table.

 

Also check if your TPS is calibrated properly (don't follow the OEM guide, just go into calibrate TPS in the Haltech settings menu and follow the 2x step procedure) if not the ECU will not enter idle state properly 

Awesome, i'll try that. Legend!

[Dose Pipe Sutututu]

22 minutes ago, ChrisW434 said:

Awesome, i'll try that. Legend!

Another way to see what the idle is doing, is to graph it in real time.

On the time graph select the idle base duty and the actual duty and the error rate.

That way you can set the base duty a bit higher than what the actual duty cycle applied to the idle control valve.

On the slow Nissan IACV, I like to set the base a tiny bit higher than the actual duty cycle during correct idle and target rpm, allowing the closed loop idle strategy to reduce the idle duty as required to meet the target 

[ChrisW434]

5 minutes ago, Dose Pipe Sutututu said:

Another way to see what the idle is doing, is to graph it in real time.

On the time graph select the idle base duty and the actual duty and the error rate.

That way you can set the base duty a bit higher than what the actual duty cycle applied to the idle control valve.

On the slow Nissan IACV, I like to set the base a tiny bit higher than the actual duty cycle during correct idle and target rpm, allowing the closed loop idle strategy to reduce the idle duty as required to meet the target 

Sounds like good advice to me. I'll work out how to do that, and have a crack. I think the remote mounted iacv might theoretically be laggy also compared to stock mounting position.

[ChrisW434]

On 31/8/2024 at 6:03 PM, Dose Pipe Sutututu said:

Another way to see what the idle is doing, is to graph it in real time.

On the time graph select the idle base duty and the actual duty and the error rate.

That way you can set the base duty a bit higher than what the actual duty cycle applied to the idle control valve.

On the slow Nissan IACV, I like to set the base a tiny bit higher than the actual duty cycle during correct idle and target rpm, allowing the closed loop idle strategy to reduce the idle duty as required to meet the target 

Ok, bit of an update with whats working..

- i think it's the fuel staying on (when i perhaps shouldn't be) at zero demand that causing the lungeing. I say this because when playing around and trying to learn about fuel cut/zero demand settings i got it to lunge bad at 30-40km/h whilst decelerating. It's almost as if the fuelling is fighting the natural engine braking and the chassis 'bounces' against the backlash in the driveline (diff especially), making it worse. I had a forester GT (w/aftermarket ecm) that used to do it, and i couldn't work out why.

- map prediction works awesome with drivability, made a big difference straight away.

 

I'll keep working on it, esp the idle quality with and without aircon. 
 

Thanks again for the help lads!

[GTSBoy]

Yeah, it won't be that the fuel stays flowing during that decel period. the only reason that OEMs have fuel cut is for emissions/consumption reasons, given that the engine doesn't really need any fuel at that time. But back in the day, with carbies, fuel continued to flow under decel.

The problem is merely with when it is cut and when it comes back in (as revs contibue to drop) and how it is brought back on when the throttle is opened again. Transient tuning is always that hard part.

[ChrisW434]

1 hour ago, GTSBoy said:

Yeah, it won't be that the fuel stays flowing during that decel period. the only reason that OEMs have fuel cut is for emissions/consumption reasons, given that the engine doesn't really need any fuel at that time. But back in the day, with carbies, fuel continued to flow under decel.

The problem is merely with when it is cut and when it comes back in (as revs contibue to drop) and how it is brought back on when the throttle is opened again. Transient tuning is always that hard part.

Yeah sorry, it's hard to articulate the conditions it falls under (i.e doesn't do it under fuel cut).

As i'm coasting and the revs very slowly come down, and the revs lower to a certain point, the car will start lungeing (conditions depending) as if it's fighting something in the tune.

Turn on fuel cut, and the car just rolls nice when coasting (no fuel).
However, the trade-off seems to be when coming back on the throttle (even slightly) it's not as smooth (as when throttling back on without fuel cut).

I'll keep experimenting with different settings and seeing what works better over time. I have a new appreciation for modified ecm cars that truly drive like oem. It's so much work to get right!

[Dose Pipe Sutututu]

Post up a screen grab of the fuel decel rpm table, might be that 

[ChrisW434]

24 minutes ago, Dose Pipe Sutututu said:

Post up a screen grab of the fuel decel rpm table, might be that 

This info?, i haven't tried the drive with the current DCDT settings, they were around 500rpm higher and only started at 2000rpm before, not 1000

Edited September 15 by ChrisW434

[Dose Pipe Sutututu]

Decel table, column 60°C add 100 rpm to all the cells, at 80°C add 200 rpm to all the cells, at 90°C at 300rpm too all of them.

On the last screen shot, set the fuel enrichment at 20%, try 25%, if it's too much you'll notice a massive rich spot/bog on transient.

I think mine is at 25% and it's just good, this is all dependant on intake manifold a d injector position.

[ChrisW434]

9 hours ago, Dose Pipe Sutututu said:

Decel table, column 60°C add 100 rpm to all the cells, at 80°C add 200 rpm to all the cells, at 90°C at 300rpm too all of them.

On the last screen shot, set the fuel enrichment at 20%, try 25%, if it's too much you'll notice a massive rich spot/bog on transient.

I think mine is at 25% and it's just good, this is all dependant on intake manifold a d injector position.

Ok, i'll make those changes to the decel table and see how that goes. Cheers.

with the fuel enrichment, ive tried different percentages all the way up to 80% just trying to get a feel for how it reacts when touching the throttle again after decel. The more fuel i add the harsher the engine snaps back to life. It gets really bad.
So i'm all the way back to 5% currently to soften the hit when the throttle is first cracked. I reckon a table with RPM axis or vacuum (demand) might be useful with this setting also...

[joshuaho96]

On 9/15/2024 at 12:22 AM, ChrisW434 said:

Yeah sorry, it's hard to articulate the conditions it falls under (i.e doesn't do it under fuel cut).

As i'm coasting and the revs very slowly come down, and the revs lower to a certain point, the car will start lungeing (conditions depending) as if it's fighting something in the tune.

Turn on fuel cut, and the car just rolls nice when coasting (no fuel).
However, the trade-off seems to be when coming back on the throttle (even slightly) it's not as smooth (as when throttling back on without fuel cut).

I'll keep experimenting with different settings and seeing what works better over time. I have a new appreciation for modified ecm cars that truly drive like oem. It's so much work to get right!

That sounds like it could be fueling or timing. Everything that you're describing is part of why it's taking me so long just to build a "base map" for a Haltech tune. I'm really trying to make everything behave as close to OEM as possible before I even connect the ECU and see how it runs against the real thing.