Hi All,

I have found only one usefull information how to make water spray on:

 

I don't know a great deal about this, but you would be better off switching from a specified boost level, or much easier to take a feed from a microswitch that triggers on full throttle.

Disadvantages of ECU switching:
expensive and complex

Disadvantage of thermal switching:

Heat soak when in traffic triggers water spray
It takes a long time for heat to build up, by which time your off the power, so water no longer needed

 

Should find out in a couple of days how effective thermal switching is.

I've mounted a K-type thermocouple inside the
intercooler near the airstream to the throttle. I'm connecting this to a termocouple chip which can be setup to act as an adjustable switched based upon temperature . This will then drive a relay in place of the pressure soleniod.

I've done some temperature measurements and the thermocouple seems to response quick enough and at an educated guess reflects the air temperature rather than the heat soak temperature of the IC.

The heat soak at idle is a concern. I've had raises upto 40C from a 30 second stop.

Setups not cheap but not too expensive. Average $90NZD on the thermocouple switch part of it.

Advantages of thermal switching (at a guess):
Spray only when needed, eg. no wasted water
at night.
Prevent heat build up in traffic conditions allowing for safer (less chance of detontaion)acceleration bursts.

Disadvantages:
Idle switch to prevent excess water dumping in stop conditions.
More complex electrically to setup.

A suggest modification to the water spray setup being looked. Use two pumps in series.
Depending on the spray nozzle this can give a better spray from the increased pressure/flow.

 

anyone know where I can get some spray nozzles from - pukka ones or something that does the same job?

 

Ian,

Look in B&Q or Homebase for the nozzles from a garden watering system. They usually have several types with "misting" being the best option.

I got mine from Homebase for £3 for 6.

MRT sell genuine STi jets, if you are after the OE parts.

Thanks

Gavin

 

Ian p, try scoobymania , Ben can get them for you.

mike

 

Hi all1!!
I am thinking of fixing a diy water spray on my 95 my uk car
Is it the same idea or is there a better way??

 

Thanks BR. I call them first thing Monday. Bought some mist nozzles from a garden centre and they don't produce a fine enough mist, I think.

 

Iain,

I've read a number of different reports about the water spray - location seems to be pretty important.

Apparently, putting the nozzles as high up the airstream as possible seems the popular choice.

How many nozzles did you fit ?

I fitted four and placed them at varying angles (pointing up the air stream and directly onto the I/C).

My suspicion is that insufficient pressure is available if you use four with a standard washer motor - I may disconnect two and see if this improves matters.

If anyone has been down this particular road, I would be interested in your findings

Thanks

Gavin

 

If you really.....really want to improve the efficiency and power of your scoobs why not do the waterspray in conjunction with an intercooler splitter.

What this does is splits (and therefore) channels the air flow more effectively into the intercooler which increases its efficiency.( denser air = more power ?)

The general idea comes from the aussies who have also tested the splitter and waterspray both single and together.

If you go to :-

 

Have fiited a splitter plate (smooth 90 deg curve), mounted the hood plate. Fitted two nozzles but only direct water onto the front of the intercooler, so I add a couple more for the rear section. Maybe mount them to the splitter. The first time I drove the car was Monday morning (w/o water spray)and although it wasn't particularly cold, the engine seemed to respond like it was a frosty morning. Initially I had forgotten that I fitted the splitter - well it was 5:30 - but was surprised at the pick up. I hope to get the same improvement again with the spray. I'll let you know.

 

O.k. O.k. try not to laugh too much but what does the intercooler do EXACTLY. I had my own assumptions, but comments on this thread have made me doubt myself

What does the Intercooler cool?
How does a fine mist of water help?
Dense air. What can that do. (thought the main air intake prefered dense air)

 

Hi David

1. Intercooler is still cooled with air.
2. Water help cool down air becouse it absorb heat.

 

David,

The intercooler cools the air going into the engine. Cooler air is more dense than warm air and will result in more power.

When the turbo compresses the air, it rises in temperature. The intercooler tries to reverse this effect as much as possible.

A good comparison is a bicycle pump which gets rather warm when pumping up tyres (from compressing the air).

If the air coming into the scoop is cooler and/or damp, the "radiator in reverse" gets colder and lowers the temperature of the air passing through it into the engine.

I think density of the air from the scoop in this instance is a bit of a red herring....

Thanks

Gavin

 

Thanks Gavin, the clearest reply I've read in ages.