Feature request: IAC throttle follower

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sd1nl
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Feature request: IAC throttle follower

Post by sd1nl »

i have the following feature request, maybe the developers could give this some thought:

I think it would be a good idea the have an IAC throttle follower option. The IAC would then follow the position of the throttle.

This in addition to all the normal closed loop IAC stuff.

It would function like this: let's say you are driving with 70% throttle. The IAC would then be opened 70% (or 80 or 60, this would be adjustable in a curve), and then if you let go of the throttle the IAC would count down to normal commanded position in 1 or 2 seconds (an adjustable period).

This way we could always have a steady predictable drop to idle and as an addition this would smooth down city driving (going on and off the throttle all the time). Also it will be easier for (certainly engines with lighte flywheels) to prevent stalling after blipping the throttle.

I think this is something that some OEM engines also do, it is not really my own idea.
Last edited by sd1nl on Mon Jun 29, 2015 12:35 pm, edited 1 time in total.
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nathaninwa
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Re: Feuture request: IAC throttle follower

Post by nathaninwa »

Have you tuned the air temp initial value table for idle control? This does just about what your asking. Based on air temp, I can have the idle valve catch the motor at about 2/300 rpm above my target in just about any situation so far
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Re: Feuture request: IAC throttle follower

Post by Magovit »

[quote="sd1nl"][/quote]

sd1nl, always with good ideas, I like it!
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sd1nl
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Re: Feuture request: IAC throttle follower

Post by sd1nl »

nathaninwa wrote:Have you tuned the air temp initial value table for idle control? This does just about what your asking. Based on air temp, I can have the idle valve catch the motor at about 2/300 rpm above my target in just about any situation so far

Of course, tuned the hell out of the initial value table. It works more or less ok. But this will never be a perfect solution.This is why OEM's have a different approach.

I also have to raise the IAC steps in the initial value table much higher than I would like too just to be on the safe side. with the IAC throttle follower you can tune much more precise. And like I said, it will smooth out city driving. i can see some people won't be bothered, butI do a lot of city driving and I like things to be smooth.
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muythaibxr
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Re: Feuture request: IAC throttle follower

Post by muythaibxr »

A number of users want the opposite of that behavior. I.e. they want to close the valve when the throttle is pressed.

I'd prefer not to have to add yet another curve and yet another option to the code. The initial value table more or less does what you are talking about when you lift off the throttle, especially configured not to close the valve.

Ken
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Re: Feuture request: IAC throttle follower

Post by sd1nl »

muythaibxr wrote:A number of users want the opposite of that behavior. I.e. they want to close the valve when the throttle is pressed.

Those people shouldn't use this option.


I'd prefer not to have to add yet another curve and yet another option to the code. The initial value table more or less does what you are talking about when you lift off the throttle, especially configured not to. A number of users want the opposite of that behavior. I.e. they want to close the valve when the throttle is pressed.

There are literally thousands of parameters and curves. I don't see why this one should present a problem


I'd prefer not to have to add yet another curve and yet another option to the code. The initial value table more or less does what you are talking about when you lift off the throttle, especially configured not to close the valve.

The initial value system isn't really perfect, you have to admit that. let's try to make it better. I 'm just thinking of ways how to. My suggestion doesn't seem overcomplicated. And if you dont want to use it, just don't tick the box.


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Feature request: IAC throttle follower

Post by muythaibxr »

This feature already confuses enough people. The initial value table tuned properly does in fact do more or less what you request.

No more curves/settings for this feature. In fact I am going to do what I can to drastically reduce what people need to tune for this feature using some ideas around fuzzy logic.

It is easy for you to say "what is one more setting among thousands" when you aren't the one supporting the feature when users are confused or have issues.
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Re: Feature request: IAC throttle follower

Post by krisr »

Ken - to a degree I agree with you but I don't agree with the "no more curves/settings" bit - as people WANT the most/more adjustment out of their systems and if they don't need that functionality, it should be simply turned off (check box, 100% value etc..), the way haltech has done it by allowing users to "profile" their cars and allowing users to "tick" the options they want to use to tune their cars is fantastic and something that might help you guys with your SDLC as it would be very modular. In terms of support, documentation and intuitive UI's will dramatically help ease support burdens or "power users" on the forum generally help immensely from what i've seen over the years. But the commercial/product model is noone elses business but yours/B&G etc..

On topic - I personally feel the IVT table is "half-way there" and needs to be expanded so that the table is based on speed/rpm and will follow the table whilst the table is active all the way down to CL-Idle (vss=0) instead of hitting a step position (once) based on load/target RPM then will get to CL-Idle when the conditions are met, but you also need a static airflow step table as a reference point based on coolant so there's a starting point to get the car to idle at varying temperatures (again, more tables needed) - the afore mentioned don't need to be based on those factors alone and user switching/dropdowns would work here so people could use whatever they wanted/needed to get the desired result. This behaviour would be what the OP is talking about I think and is how the OEM's did the LS1's in the delphi system. But there is another element that hopefully is in consideration and that is not everyone uses a manual transmission and in cases with automatic transmissions, big cams, big converters, the airflow, spark and fuel and differ slightly to get the car to idle both in gear and out of gear.

2c and all that jazz.

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sd1nl
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Re: Feature request: IAC throttle follower

Post by sd1nl »

muythaibxr wrote:This feature already confuses enough people. The initial value table tuned properly does in fact do more or less what you request.

No more curves/settings for this feature. In fact I am going to do what I can to drastically reduce what people need to tune for this feature using some ideas around fuzzy logic.

It is easy for you to say "what is one more setting among thousands" when you aren't the one supporting the feature when users are confused or have issues.
Ok. Although I'm dissapointed,I respect your opinion and awaiting improvements on this part of the system anxiously.
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Re: Feature request: IAC throttle follower

Post by sd1nl »

Maybe an idea that would improve things but would fit better in the current firmware setup:

After dashpot adder steps are added, they would then count down over a period of time. Make this time adjustable, in a range from 1 to 5 seconds let's say (or infinite if you don't want to use it).

The drop to idle would then be somewhat better adjustable, without overcomplicating things.
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Re: Feature request: IAC throttle follower

Post by muythaibxr »

The drop to idle is already controllable using the ramp to target variable.
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Re: Feature request: IAC throttle follower

Post by sd1nl »

Ehhh, sorry but that is not the drop to idle...

You mean the ramp to idle taget AFTER the engine has entered closed loop idle. The rpm drop has been long gone by then.........
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Re: Feature request: IAC throttle follower

Post by nathaninwa »

I have thought about this for the last few days. I have an ms3 semi cammed 2j and a darn near bone stock 22re on ms2. Both run the same ford Pwm idle motor and the only problem I have is when the 2j is cold, gear decelling down a slight grade where I'm already in closed loop idle, a clutch stop at the bottom the motor will stumble down to about 500rpm from a slight lack of initial duty since that time had already passed, and this feature would not really fix it since I'm off the throttle.

The initial values and settings there seem to work good, and 90% of my driving is stop light to stop light as well

Once I switched to an airtemp lookup for the initial values, I've been really able to get decel into idle pretty dialed
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Re: Feature request: IAC throttle follower

Post by muythaibxr »

sd1nl wrote:Ehhh, sorry but that is not the drop to idle...

You mean the ramp to idle taget AFTER the engine has entered closed loop idle. The rpm drop has been long gone by then.........
Are you talking about immediatly after lifting or after RPM settles?
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sd1nl
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Re: Feature request: IAC throttle follower

Post by sd1nl »

The period between lifting throttle and entering closed loop.

Basically I want better control over de rpm drop.

In an ideal universum I would like to be able to set this drop as a user definable parameter in rpm/s and have MS3 control this drop closely umder al circumstances. No graphs, no dashpot adder: just that one parameter (lets call it the "dashpot" parameter)

A few firmwares ago there was something that was going in the right direction, the dashpot decay factor.
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Re: Feature request: IAC throttle follower

Post by piledriver »

muythaibxr wrote:This feature already confuses enough people. The initial value table tuned properly does in fact do more or less what you request.

No more curves/settings for this feature. In fact I am going to do what I can to drastically reduce what people need to tune for this feature using some ideas around fuzzy logic.

It is easy for you to say "what is one more setting among thousands" when you aren't the one supporting the feature when users are confused or have issues.
I think what most really need is not to have to wait 2 seconds (minimum) before closed loop kicks in.
I do not have a hipo motor or lightweight flywheel, but it is still typical for the RPMS to have dropped well below the target prior to the CL and IAC etc kicking into their presets.
Having aggressive timing and well tuned fuel in the cranking column of the tables keeps it from stalling, usually.

I guess I should go mucking about in the ini again...
Always doing things the hard way, MS2 sequential w/ v1.01 mainboard, LS2 coils. 80 mile/day commuter status.
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Re: Feature request: IAC throttle follower

Post by nathaninwa »

Ms3 doesn't have that 2 second delay. I have an ms2 and an ms3. My 3 is set to 0 seconds and wish my ms2 could too
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Re: Feature request: IAC throttle follower

Post by sd1nl »

nathaninwa wrote:Ms3 doesn't have that 2 second delay. I have an ms2 and an ms3. My 3 is set to 0 seconds and wish my ms2 could too
You can easily change that yourself bij changing one line the ini file, and set the minimum to "0" instead of "2" . I did that also when I was running on MS2.

In found that 1s was the best setting for me though.
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Re: Feature request: IAC throttle follower

Post by muythaibxr »

If rpm is dropping too low before closed loop kicks in, the initial value table is wrong. The delay should be used to allow the engine to become stable before closed loop engages.
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Re: Feature request: IAC throttle follower

Post by nathaninwa »

For me it's just the time delay. The idle catches really well about 150 above target, then 2 second pause for it to idle down. Not a huge deal, but i do like the option to set it up lower on ms2
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