Intercooler water spray project

Hi everyone,

New to the forums and infact totally new to Arduino, so much to learn and take on board - But i thrive of a good challenge! - already have a handfull of ebooks and working my way through the info in them.

I have just ordered what i believe are all the parts i need for a mock up version of a intercooler water spray for my car.

What I am looking for achieve is as follows.

The only time the spray needs to operate is when the intercooler itself (not the intake air temp!) is hot and the engine is under moderate/high load. Furthermore, the longer the spray has run, the longer it should keep running after the load or temperature drops below the trigger point. (Why? Because it’s likely that the amount of heat stored in the intercooler will then be greater.)

Having a spray controller that takes into account the above points automatically allows for:

  • Days where it’s raining (and so the intercooler is already being sprayed with water!)
  • Short bursts of boost (where the intercooler won’t have risen much in temperature)
  • Hard driving where there’s lots of full throttle work mixed with zero throttle (the spray will keep running during gear changes and quick throttle lifts for corners)
  • How effective the spray actually is at cooling (weather with low relative humidity will allow the spray to work more effectively, so it doesn’t have to be on so long)
  • Variations in road speed and so airflow (eg you’re stuck behind a truck slowly climbing a long hill)

There are quite a few variables i need to set up, they include...

  • Inlet Manifold Temp
  • Intercooler in temp
  • Intercooler out temp
  • Throttle Body Postion - (how much gas im giving the car)
  • Boost Level - (in addition with the above can calculate how much power im requesting from the engine)
  • Airflow - (am i actually moving or in traffic) - but this uses a frequency reading, not sure how to deal with this yet.
  • Windscreen wipers (or a rain sensor) - If on, override system and do not spray water
  • Water level - reading, light a LED if no water
  • Master override switch - device on, off

So if 1, 2,3,4, 5 and 6 are triggered (thresholds yet to determined), spray water (or light LED in mockup) - otherwise do nothing.

I realise there is alot of inputs and ifs and buts but I will be taking this project one step at a time, once I have mastered one element i will introduce the next untill everything has been taken into account.

The first port of call will be to determine the temperature of the inlet manifold, the inlet of intercooler and outlet of intercooler.

I will go forth and search the forums for info on determining temperature and performing an action (spray water) based on that, unless someone already knows of a good article/guide on peforming this action?

P.s. the mock up will use LED's to represent the water being sprayed - eventually once everything is working i will start planning the car installation.

Personal reference Guide.

Related Threads.

- http://arduino.cc/forum/index.php/topic,108020.0.html

Thanks for reading!

P.s. the mock up will use LED's to represent the water being sprayed - eventually once everything is working i will start planning the car installation.

How will lighting an LED affect the intercooler inlet and outlet temperature readings? I thought the idea of the project was to make something happen to affect those values.

Otherwise, the only challenging part of your project is to find temperature sensors with the right range, and mounting them in such a way as to get an accurate temperature.

You might use a thermocouple like this:

http://www.alpha-crucis.com/en/sensors-en/2668-thermocouple-type-k-glass-braid-insulated-3700386502705.html

Should stay alive even in your harsh environment.

Thanks for the response - the LED’s are only part of the mock up phase, so to replicate the water pump being activated a LED will be lit.

I have purchased a number of Thermistors which i can use to measure the temp, i think one challenge will be to determine exact temperatures, for example boil some water, take measurement with thermometer and then measure that against the reading the thermistor reads - quite a rudimentary method i know, so welcome any advice on calibrating them.

The LEDs may be fine for your very first test of your system, but you will rapidly need something that impacts the temperature being read, otherwise you can't test your control logic. A fan blowing over ice water for example.

Indeed you are correct - However there are quite a few variables i need to set up, they include...

  • Inlet Manifold Temp
  • Intercooler in temp
  • Intercooler out temp
  • Throttle Body Postion - (how much gas im giving the car)
  • Boost Level - (in addition with the above can calculate how much power im requesting from the engine)
  • Airflow - (am i actually moving or in traffic) - but this uses a frequency reading, not sure how to deal with this yet.
  • Windscreen wipers (or a rain sensor) - If on, override system and do not spray water
  • Water level - reading, light a LED if no water
  • Master override switch - device on, off

So if 1, 2,3,4, 5 and 6 are triggered (thresholds yet to determined), spray water (or light LED in mockup) - otherwise do nothing.

Airflow - (am i actually moving or in traffic)

Just read pulses from the tail shaft or other rotating part.


Rob

You have listed lots of possible inputs, including some that would need considerable analysis to work out the implied water spray requirements.

A relatively simple algorithm which I've used for primary cooling fan control is to measure the charge air out temperature from the intercooler. If the intercooler is not capable of keeping this within a suitable window of ambient then you know that it has not had enough ram air flow plus rain plus all the other factors affecting the intercooler, relative to the amount of heat it is being asked to remove from the charge air, for long enough for the cooler itself to heat up. That can be your signal to add some evaporative cooling. In other words you measure whether the intercooler is doing its job successfully, and help it if it isn't. If it ends up needing lot of help, that's your clue that the intercooler is not adequately rated for that application.

If your car has an engine management computer then the all the sensor values are there for you on tap, my Nissan had an ecu and using an obdII interface I could connect to it and read off any values.

A low reading from the air intake temp will advance the timing a few degrees and improves performance, as you can control the timing through obdII, you can get a boost on demand.

I have to say though any non factory approved modifications may well void any warranty and maybe insurance too.

Thanks for your response, you are indeed correct and the end goal is to plum into the ECU, here I will be able to get pretty much all the inputs required, however as I am in prototype stage I will be using alternatives to replicate those signals. I already know the voltages they use, right through the range so that isnt a problem.

Warranty? Heh no worries, the car is 15 years old :) insurance will also not be a problem as it will be declared like all of my other perfOrmance mods.

I do however value you response and it does fall inline with the end goal of this project.

Anything other ideas or suggestions will be most welcomed!

I haven't investgated Atmel chips enough to know if there are any with built in CAN bus, the obdII interface i got of ebay for around £10 and it outputed straight rs232 making life a whole lot easier to read into a uC and display on lcd

P18F4550: I haven't investgated Atmel chips enough to know if there are any with built in CAN bus, the obdII interface i got of ebay for around £10 and it outputed straight rs232 making life a whole lot easier to read into a uC and display on lcd

I'll also be using evoscan to help with pinpointing the inputs etc, but thats a wee bit down the line - firstly i need to understand the product (arduino), the code and make the simple inputs trigger the LED, which represents the Water bottle pump - from there it will expand to the full list of inputs/outputs mentioend in post #1

I haven't investgated Atmel chips enough to know if there are any with built in CAN bus,

I'm pretty sure the new Due has CAN.

See the connector labels at the bottom right.


Rob

He bits have started arriving from eBay, by Wednesday I should be able to start putting together phase 1, which consists of 1 termister, calibrated and have this configured to activate an led at a preset temp (close to body temp) the led will represent power doing to a relay which will eventually run the water pump.

phase 2 will see a preset introduced which represents the throttle body, again once that is at 50% and thermistor threshold is hit the led will light. Phase 3 will have another preset added, this will represent the boost level. Phase 4 adding on off switch to replicate windscreen wipers being on and thus disabling everything

This should then the the basis of te entire unit, from here I can further expand an elaborate on it's uses.

Will update thread once phase 1 is completed, I may start a separate thread should I encounter problems or require guidance.