Aux air regulator prototype Options

[emerygt350]

Well, it works on my desk and it works on 12v. Might get around to trying it in the car today.

[Superhawk996]

(IMG:style_emoticons/default/popcorn[1].gif)

Have considered the same approach.

I’ve also considered something similar to replace the MPS but haven’t found a good way to vary the inductance in a smooth linear way without a Rube Goldberg contraption of windings and a linear actuator.

[Literati914]

It'd be great if you guy could figure this stuff out.. it's just these type of individual items that make D-jet less attractive as a long term solution (they've already been that). Yes we like the old school analog but those become less available as time passes, and it seems like just a matter of time 'til replacements are dried up.

maybe the same could be done for the decel valve ? (IMG:style_emoticons/default/popcorn[1].gif)

[FlacaProductions]

Very cool!

[JamesJ]

Well, it works on my desk and it works on 12v. Might get around to trying it in the car today.

Oil pressure: check
Oil temp: check
Coffee temp: check

[tomeric914]

https://xwebforums.com/forum/index.php?thre...ernative.38379/

The link above was from 5 years ago so I don't know if the same parts are still available. Looks like it gives some user adjustability without the use of a computer.

Fiat X1/9, Porsche 914, close enough.

(Did you come to any of the events at the Glen this year?)

[emerygt350]

That looks a little like what I am up to but minus the brain. I am adding routines based on ambient temp and also adding a 4 second open on start to help with our poor hot engine starts with djet. The nice thing with the Arduino is I can rewrite the code and update the system without pulling anything apart or adding/subtracting resistors and so on.

I was at the vintage races as well as the NASCAR cup this year. Thinking about the last Glen region scca autox this weekend but not sure about that yet. At least I think it's this weekend....

[emerygt350]

Progress

[emerygt350]

More progress. Ready for a test run.

[emerygt350]

Here are my routines so far. Anybody think of any other things I can try to address with the AAR? The temp sensor is ambient temp, about 3 or 4 inches from the block.

#define ADC_VREF_mV 5000.0 // in millivolt
#define ADC_RESOLUTION 6000.0
#define PIN_LM35 A0
// constants won't change
const int RELAY_PIN = D8; // the Arduino pin, which connects to the IN pin of relay

void setup() {
Serial.begin(9600);
// initialize digital pin as an output.
pinMode(RELAY_PIN, OUTPUT);

// get the ADC value from the temperature sensor
int adcVal = analogRead(PIN_LM35);
// convert the ADC value to voltage in millivolt
float milliVolt = adcVal * (ADC_VREF_mV / ADC_RESOLUTION);
// convert the voltage to the temperature in Celsius
float tempC = milliVolt / 10;
// convert the Celsius to Fahrenheit
float tempF = tempC * 9 / 5 + 32;

//High idle for ~4 seconds on every start up. delay is how long to wait before moving to the next instruction. Delay is in milliseconds
digitalWrite(RELAY_PIN, HIGH);
delay(4000);

//Hot start routine to address low idle when restarting hot
//will probably need to move that temp around to get this right
if (tempF >99){
delay(10000); //hotstart 10 second additional high idle
digitalWrite(RELAY_PIN, LOW);
}

//Warm start routine
if (tempF <90 and tempF >70){
digitalWrite(RELAY_PIN, HIGH);
delay(60000);
digitalWrite(RELAY_PIN, LOW);
}

//Cool start routine
if (tempF <70 and tempF >50){
digitalWrite(RELAY_PIN, HIGH);
delay(120000);
digitalWrite(RELAY_PIN, LOW);
}

//Cold start routine
if (tempF <50) {
digitalWrite(RELAY_PIN, HIGH);
delay(240000);
digitalWrite(RELAY_PIN, LOW);
}
}

void loop() {}

[emerygt350]

dupe

[Superhawk996]

So it looks like Arduino is just controlling via high/low binary.

Does the valve have some sort of built-on ramp rate on the open & close? Or, is this just an open / close solenoid valve?

[Ishley]

Do you need a default routine that the code falls into after a specific amount to time that closes the valve... in the case where you you don't sense the temp? I'm not familiar with this language so perhaps it's there and I didn't get it.

[emerygt350]

So it looks like Arduino is just controlling via high/low binary.

Does the valve have some sort of built-on ramp rate on the open & close? Or, is this just an open / close solenoid valve?

yes, it's just telling a relay to trigger. That sends the 12v to the valve, which is just on or off. I am hoping this will be enough. I notice in my car the ramping closed is kind of redundant because the ecu richens the mix enough that after a minute running if I turn off the air flow off it will still idle at 1400.

[emerygt350]

Do you need a default routine that the code falls into after a specific amount to time that closes the valve... in the case where you you don't sense the temp? I'm not familiar with this language so perhaps it's there and I didn't get it.

This is just a run once routine that would only execute the moment you start the car. no loop.
There is an initial 4 sec open routine regardless of the temp.

[Superhawk996]

There is an initial 4 sec open routine regardless of the temp.

What the thinking there?

Example - car is hot to very hot. Shut down for let’s say two minutes. At restart it’s going to tend lean just based on temp. Why bleed in more air for 4 seconds when the AAR wouldn’t?

Not being critical - think this is cool that your giving it a whirl and of course if it doesn’t work for whatever reason easy to change code.

There are probably 5 good ways to do this with stepper motors or a solenoid that could be PMW controlled but you’ve actually done something and built something so my hats off to you!!

(IMG:style_emoticons/default/smilie_pokal.gif)

[emerygt350]

There is an initial 4 sec open routine regardless of the temp.

What the thinking there?

Example - car is hot to very hot. Shut down for let’s say two minutes. At restart it’s going to tend lean just based on temp. Why bleed in more air for 4 seconds when the AAR wouldn’t?

That would be the sane thought here, but since this is djet... I think the logic behind the tough start is the heads cool faster than the cylinder and therefore the head temp isn't reflective of the actual temp ending up in a rich condition. I don't know if I believe that or not, considering how heat moves in these engines.

Whatever the underlying cause, when hot in the condition you describe, my car idles low, so I am going to try bring that idle up for 14 seconds (4 seconds because it is a fresh start, and 10 added because the temp sensor sees a hot engine bay). That is the normal amount of time it takes for my car to recover a normal idle in a hot restart situation. I am not sure this will work, or if those are the right times, but it is a start.

The stepper might be where I go next if this doesn't have the resolution needed. I was also looking at a multivalve system. I am afraid that most of the cheap valves of the right size and voltage just don't create a hole big enough for the airflow I need. If I had two valves in parallel, that would give me the ability to roughly alter air available.

We will see. I have a PCA event this weekend so I don't think I will try it on the car till Sunday.

sadly, if they had just added the 6cyl throttle lever to the 4 and dumped the stupid aar, we wouldn't need any of this.

[rjames]

Very cool and imporessive work!

sadly, if they had just added the 6cyl throttle lever to the 4 and dumped the stupid aar, we wouldn't need any of this.

When you first posted this thread I came close to suggesting a manually operated AAR that could be controled form inside the cabin. (IMG:style_emoticons/default/biggrin.gif)

[emerygt350]

Very cool and imporessive work!

sadly, if they had just added the 6cyl throttle lever to the 4 and dumped the stupid aar, we wouldn't need any of this.

When you first posted this thread I came close to suggesting a manually operated AAR that could be controled form inside the cabin. (IMG:style_emoticons/default/biggrin.gif)

It would be soooo easy. I already have a valve on mine for troubleshooting, add a choke cable... But I like a challenge!!!! Or I'm just stupid. Probably the later. I was thinking about using my Bluetooth switch to just manually open the relay but this is soooo much more rube goldberg.

[tomeric914]

This is probably just a prototype, but I suggest you make the case out of aluminum to stand up to the heat, or Nylon 6-6 which is good to 450 deg F or so.

I was at the vintage races as well as the NASCAR cup this year. Thinking about the last Glen region scca autox this weekend but not sure about that yet. At least I think it's this weekend....

I failed to get the 914 to any events this year, partially because I need to adjust the clutch pivot and partly because I don't feel like getting run over by the 500+ hp cars that are the norm now. The event to go to for 914s is the September GVC BMW event because there was a proliferation of 2002s and early Lotus cars that would be fun to play with.