Let the tinkering begin...

[572]

Ideally hook the fan up to a pressure switch, so it only runs when your speed is low, and it can then just freewheel at speed. If it's running, at 100kph, it would probably be a restriction at a guess.

I was thinking just a standard switch at first, see how it performs. I can monitor inlet air temps on the ScanGauge. Through light traffic I see about 35-40deg, seen up to 70deg+ though!

Also make sure the side mount has good inlet and especially outlet air flow. I'd also consider insulation on the pipe from the cool side to the manifold, even if only at any potential "hot" points, near the engine etc. I plan on wrapping the entire cool side once I'm done.

Now there's a point. There is no outlet in the guard behind the intercooler, just solid plastic inner guard.

Maximise what you have! Autospeed had a GREAT test of various wrecker intercoolers, so might be worth having a look if any of these jap items would be a possible, more efficient, cheap upgrade for the Polo. Perhaps even in series with the stocker. Remember a bigger cooler will be more efficient, but will also add volume and drop boost. You're trying to offset any volume boost loss with enough increase in air density to make it worthwhile.

To be honest, I can get a FMIC to fit the Polo perfectly for a tad over $300, so I'd go that path if I decided to bin the side mount.

[Greg Roles]

OK, Jon motivated me to pull a half day at work, so I spent this morning shredding my arms putting a thermo probe just prior to the intercooler, and the second about half way from the intercooler outlet before the EGR circuit. Had to be these places as these we the only "normal" clamp spots where I could sneak a wire into the tubes.

Thus far on the drive in, which was quiet given a lot of traffic, I was pleased to see on a 27-28 degree day, the post intercooler temps remained about 8-10 degrees over this at about 35-38 degrees, and a few mid level 10-15psi squirts, which saw the before temps rise into the 70-80 degree range had virtually no effect post cooler. Early days, but seems the stock cooler handles normal traffic boost temps very very well.

Where it DID fall down, again early days, but on idling at a set of lights over 2 mins, the post temps rose into the 40's, and remanined there even after moving off. Perhaps the tubes themselves got hot, and the temp sensor is probably in direct contact, but at the lights it was interesting to watch the pre temps drop, and the post temps rise, as they headed towards equalling out.

Makes sense, but it was interesting that the post temps didn't drop back below 40 even after several minutes of quiet driving. Heat soak, and the lights particularily are things I'll keep an eye on!

Will continue to monitor, and once I get the two additional channels hooked up, I can monitor actual air filter ambient temp, and hopefully manifold temps after the EGR addition. Add that to my EGT's I hope to do Friday and things should get interesting.

My lower intercooler hoses were oil lined, but not too badly, no pools or drips, so the Provent is doing it's job. The EGR body was heavily coated in black sludge, which I cleaned out to the best of my ability, so I can only imagine what you non Provent types have coating your manifold and inlet ports. My car is at 30k's.

Not a fan of this EGR circuit!

[Greg Roles]

Now there's a point. There is no outlet in the guard behind the intercooler, just solid plastic inner guard.

Perhaps just ensure it is directed downwards, rather than opening up into the wheelarch, as you then expose the rear of the cooler to rocks and mud!

[Greg Roles]

Ok drive home. Driving along "normal" in traffic on a "about" 30 degree day, and 5-10 psi max, saw 70 degree pre cooler and 40 degree post. Drops to 37-8 post on moving. If you get a little spirited, and drive harder, at about 15psi maxes, you see 80 pre, about the same 40 degree post. This is where I'd figure most people would drive.

Up the nice little twisty mountain near home, where I can give it a 3rd gear flooring at the bottom and change into 4th for a bit, I saw 120 pre intercooler at the top, and the 40 degree post cooler at the bottom of the hill went to, wait for it.....42 degrees.

Seems the stock intercooler is handling spikes well, and running approx ten degrees over "ambient", before the EGR addition at least!

[Transporter]

Ok drive home. Driving along "normal" in traffic on a "about" 30 degree day, and 5-10 psi max, saw 70 degree pre cooler and 40 degree post. Drops to 37-8 post on moving. If you get a little spirited, and drive harder, at about 15psi maxes, you see 80 pre, about the same 40 degree post. This is where I'd figure most people would drive.

Up the nice little twisty mountain near home, where I can give it a 3rd gear flooring at the bottom and change into 4th for a bit, I saw 120 pre intercooler at the top, and the 40 degree post cooler at the bottom of the hill went to, wait for it.....42 degrees.

Seems the stock intercooler is handling spikes well, and running approx ten degrees over "ambient", before the EGR addition at least!

It sounds like that there is not much room for improvement.

[Preen59]

Yeah you heard me!

[Greg Roles]

It sounds like that there is not much room for improvement.

No such thing in my world, there's ALWAYS another 0.01% to be had.

Today on a trip down the Gold Coast and back, same deal, the output of the cooler is in the high 30's on a 30 degree day, and spikes up to 100C pre cooler have no effect. Obviously there is great airflow at 100kph plus.

I'd test longer, but I've a whistle, so despite my best efforts and some silastic, I've got a leak. It's still showing normal boost pressure though, so it can't be much. I'll mount the temp probes properly in my forthcoming upgraded pipework.

I'm convinced a water spray at heat soak times, especially idling for longer than a minute, and a fan to draw the mist in at the same time is the way to go. Good news as a water intercooler setup was going to be a major mod, and there's just no need for street driving in the MKV from these results.

Might be different on the twin boosted TSI.....

[POLARBEAR666]

No such thing in my world, there's ALWAYS another 0.01% to be had.

Today on a trip down the Gold Coast and back, same deal, the output of the cooler is in the high 30's on a 30 degree day, and spikes up to 100C pre cooler have no effect. Obviously there is great airflow at 100kph plus.

I'd test longer, but I've a whistle, so despite my best efforts and some silastic, I've got a leak. It's still showing normal boost pressure though, so it can't be much. I'll mount the temp probes properly in my forthcoming upgraded pipework.

I'm convinced a water spray at heat soak times, especially idling for longer than a minute, and a fan to draw the mist in at the same time is the way to go. Good news as a water intercooler setup was going to be a major mod, and there's just no need for street driving in the MKV from these results.

Might be different on the twin boosted TSI.....

My results from watching scangauge 2 Intake air vs Outside air temp comparison is the same as yours. On the TSI it is always within 5-10 of ambient except when it has heat soaked from the lights or from thrashing on a hot day and then it will struggle to come back down to within 10 degrees even after driving for a while at speed. This is where a waterspray will own.

I have ordered:
AutoSpeed Microswitch $4.05
AutoSpeed Spray Nozzle Kit $31.95 AutoSpeed Washer Pump with Grommet $59.35

I will be plumbing this to face towards the whole aircon/radiator/intercooler from the front grill. so that the spray enters that whole area as part of the airstream.

The microswitch will come off my throttle so that whenever I am at full throttle it will start spraying. Because of DSG you don't really take your foot off the pedal so whenever I give it a squirt the water will spray and then as you back off your intercooler will be soaked with water and still keep cooling down nicely as you drive.

The key with our intercoolers is getting the core back down to a cooler temp after a boost event so that when the next one hits it can soak it up.

I am also going to to plumb it into a 10L tank or something which I might mount in the battery area and then put my small Deka on top.

[Greg Roles]

10 L = 10kg weight weenie! You don't have the torque to carry it!

I'm going the Autospeed "ultimate" coffee pump job, and facing it forwards, drawing from the windscreen washer tank. It's 3L and already there.

Triggering it is the key, for it's the heatsoak at the lights which is the biggest issue I've noticed. Boosting at speed makes no difference, so I am thinking pressure switch and post cooler temp switch, so I can have it run when airflow is low, and it's getting hot after the cooler. I am onto my guru old man to set me up a radiator fan switch in conjunction with this, to move the mist and air through it at the lights after a certain temp.

I saw 50 degrees post cooler today, in traffic, after a long drive, it was a hot day though. seems to like to be down around 40, but does take a while to get back down.

A sprint away from the lights, to 100k is returning about 100 degrees out of the turbo, but again on normal driving today is was "around" 70.

Before I take it out I'll give it a major effort up Nebo or something, just to see where the temps "ceiling" is.

[POLARBEAR666]

3L factory + a 5L container that gravity feeds into it should do the trick.

[Transporter]

No such thing in my world, there's ALWAYS another 0.01% to be had.

Today on a trip down the Gold Coast and back, same deal, the output of the cooler is in the high 30's on a 30 degree day, and spikes up to 100C pre cooler have no effect. Obviously there is great airflow at 100kph plus.

I'd test longer, but I've a whistle, so despite my best efforts and some silastic, I've got a leak. It's still showing normal boost pressure though, so it can't be much. I'll mount the temp probes properly in my forthcoming upgraded pipework.

I'm convinced a water spray at heat soak times, especially idling for longer than a minute, and a fan to draw the mist in at the same time is the way to go. Good news as a water intercooler setup was going to be a major mod, and there's just no need for street driving in the MKV from these results.

Might be different on the twin boosted TSI.....

At the racetrack you can fill up with icy cold water but in the normal driving conditions you water in the bottle will be at the ambient temperature and will have minimum impact when used for cooling your intercooler. You can wind the hose from the bottle around air con pipe to cool the water for intercooler down or use peltier device from small car fridges to make it more worthwhile.
Just my 2c.

[POLARBEAR666]

At the racetrack you can fill up with icy cold water but in the normal driving conditions you water in the bottle will be at the ambient temperature and will have minimum impact when used for cooling your intercooler. You can wind the hose from the bottle around air con pipe to cool the water for intercooler down or use peltier device from small car fridges to make it more worthwhile.
Just my 2c.

ACTUALLY, physics called and said that your opinion got REJECTED! heheh

"Evaporating a kilogram (ie a litre) of water requires 2257 kilo-joules of energy – and that’s a lot! If the nozzle flows 400 ml/minute, and if all the water evaporates, each minute 903 kilo-joules of energy are extracted. One joule per second is the equivalent of 1 watt, so fully evaporating 400 ml/min of water provides a cooling power of 15 kilowatts! Even a 130 ml/min spray provides a potential cooling power of just under 5kW.

The key point is that the water must evaporate – it is this change of state from water to a gas which absorbs the energy. If the water droplets do not evaporate, they basically provide almost no cooling performance. And the key to getting water to evaporate is to use very small drops – an atomised mist – which dramatically increases the surface-area-to-volume-ratio of each drop, promoting evaporation.

In addition to drop size, the rate of evaporation will also depend on the relative humidity of the air (if you like, an indicator of how much ‘room’ there is left in the air for evaporated water) and the temperature of the heat exchanger.

With a good enough spray, there is no technical reason why the temperature of the intercooler cannot be brought lower than ambient. After all, that’s how evaporative air conditioners work..."

So in summary, the water temperature hardly matters as it will still evaporate when faced with a large amount of incoming air (even hot air and even if the water is hot itself). There will almost always be some evaporation unless you have very high humidity.

[Transporter]

ACTUALLY, physics called and said that your opinion got REJECTED! heheh

"Evaporating a kilogram (ie a litre) of water requires 2257 kilo-joules of energy – and that’s a lot! If the nozzle flows 400 ml/minute, and if all the water evaporates, each minute 903 kilo-joules of energy are extracted. One joule per second is the equivalent of 1 watt, so fully evaporating 400 ml/min of water provides a cooling power of 15 kilowatts! Even a 130 ml/min spray provides a potential cooling power of just under 5kW.

The key point is that the water must evaporate – it is this change of state from water to a gas which absorbs the energy. If the water droplets do not evaporate, they basically provide almost no cooling performance. And the key to getting water to evaporate is to use very small drops – an atomised mist – which dramatically increases the surface-area-to-volume-ratio of each drop, promoting evaporation.

In addition to drop size, the rate of evaporation will also depend on the relative humidity of the air (if you like, an indicator of how much ‘room’ there is left in the air for evaporated water) and the temperature of the heat exchanger.

With a good enough spray, there is no technical reason why the temperature of the intercooler cannot be brought lower than ambient. After all, that’s how evaporative air conditioners work..."

So in summary, the water temperature hardly matters as it will still evaporate when faced with a large amount of incoming air (even hot air and even if the water is hot itself). There will almost always be some evaporation unless you have very high humidity.

I never said that water wouldn't cool the intercooler.
And for normal driving there is minimum benefit.
I know my physics too mate, no need to lecture me with the last minute goggled stuff what's the point? heheh.

[Greg Roles]

You two argue in someone else's thread! Polar, just do what you know works, it's what I'm doing. I've decided to leave the temp probes in there so I can see what a spray will do for it, but I'll try and plug the small air leak over the weekend.

I'm afraid I'm 100% in agreeance with my weight weenie friend.

[mollins]

always wanted to do a waterspray.. maybe when the mk1 is finished!..

btw, i drove a mk5 TDI last night.. first time in a mk5..







i want one....


keep up the great work cogdoc