[wjbell]

Found a place in town that had brass mister nozzles rated for 80psi that are suppose to have a really fine mist. Comes with a removable filter. Only $3 ea.

So I rigged up my holley red to pump the water and put a bigger spring in it. I think it's putting out about 20psi now. I know I'll probably need more psi to the tip but it is misting ok now. And I'm sure the holley will eventually fail, not being made for pumping water, but this is just my prototype.

Anyone see any problem with misting the trans cooler? The problem is, there's not good access to just mist the intercooler. It's blocked by the ac and trans radiators.

I'm going to hook up my scanguage and do a couple of hwy runs with it misting and without to see if the scangauge shows an intake temp change.

 

[Dad]

Can't do anything driving in the rain doesn't already do it wouldn't seem.

I've done some reading on how hot the charge air gets when it is compressed by the turbo. The consensus data on smaller turbos like the HX35 was about 10 degrees per each PSI of boost. So at 20 PSI, your charge air would be 200 degrees on the inlet to the cooler.

Be interesting to see some temp readings before and after the cooler to see what was really going on. I'd imagine the mister will help significantly if the water is actually getting to the cooler with a 60-70MPG wind effecting it.

 

[wjbell]

Can't do anything driving in the rain doesn't already do it wouldn't seem.

I've done some reading on how hot the charge air gets when it is compressed by the turbo. The consensus data on smaller turbos like the HX35 was about 10 degrees per each PSI of boost. So at 20 PSI, your charge air would be 200 degrees on the inlet to the cooler.

Be interesting to see some temp readings before and after the cooler to see what was really going on. I'd imagine the mister will help significantly if the water is actually getting to the cooler with a 60-70MPG wind effecting it.

Yeah, I'd like to put a thermocouple probe directly in the air stream on inlet and out to get real readings, but don't really want to start messing with my intercooler boots. (loosening then and clamping a probe in) For now I'll see what the scangage says.

 

[Dad]

I didn't see you had a Scanguage. So you are getting an IAT sensor reading? That should tell you exactly what the mister is doing.

Wonder about mounting the nozzle behind the front license plate spraying up? So you hit the center of the cooler..??.. I'm not sure how far 20PSI is going to spray in a 70MPH wind..

 

[wjbell]

I didn't see you had a Scanguage. So you are getting an IAT sensor reading? That should tell you exactly what the mister is doing.

Wonder about mounting the nozzle behind the front license plate spraying up? So you hit the center of the cooler..??.. I'm not sure how far 20PSI is going to spray in a 70MPH wind..

Question about the scangauge... if it's reading intake air temp should it go up considerable when you're on the throttle and cool down when off? Mine only registers a difference between slow driving and hwy speeds. Slow driving it stays around 125-130F and hwy it's about 116-119F. I'm thinking either I set up the scangauge wrong when choosing vehicle type or who knows. How does your react on the f AT reading?

 

[BigBlue]

Buddy of mine has been doing some IAT testing. Air temp coming out of the bottom turbo going in to the intercooler is 300-350*. The air temp coming out of the intercooler going into the motor is around 100-150*.

 

[DRFTR]

why not just add a line with a t into the windshield washer sprayer, or better yet pull them out of the hood and remount so they spray the intercooler.

 

[Mopar1973Man]

I've also been doing IAT testing as well. What I found out is the ECT and IAT sensors will match temps at cold start up. But as the coolant temps rise so does the temp of the manifold of the head. So typically I will see match temps at start up. Then as the coolant temp rises to 190*F its about a 40*F offset for the IAT sensor. So if its 70*F outside then the IAT will show 110*F. So another example of this is middle of winter time and its -20*F the IAT was showing about 20*F typically... The only time this rule is NOT true is when the engine isn't running or just idling at a stop then the IAT temp will start rising up to mean the coolant temps. The problem is that the coolant in the head pre-heat the air enter the cylinders. There isn't a whole lot you can do about that...

If your thinking of moving the IAT sensor remember the sensor has to see the temps after the grid heater to control the off/on switching. Not to metion that moving the IAT to a cooler location will cause it to change fuel and timing... It might not be in the best interest to move it...:w:

 

[wjbell]

Well, got a Shurflo in town for $65 and put in a second nozzle. The Shurflo works awesome, it cycles on and off as it need to for pressure. probably turns on once every 45 seconds and only runs about 1 second to build up the pressure.

Any ideas on better placement of the nozzles? Well, I'll see if this does any good at all...

 

[wjbell]

Update.

From running the truck and watching the misters the hot side of the intercooler is evaporating the water and the cold side wasn't. So I put both misters on the hot side and it is evaporating soon after contact with the intercooler. And from what I understand, the evaporation is what you want. Just getting the intercooler wet doesn't do anything.

Now whether I'm getting enough evaporation on enough surface area to make a difference in intake temp, I don't know. According to my Scangauge2 it's making very little difference, but I don't think where scangauge gets it's temp from accurately reflects changes in intercooler temperature.

Some things I found in testing today:

- Intake temperature according to scangauge is about 45-50* hotter than ambient temp while moving

- Intake temperature while idling stopped gets about 55-60* hotter.

- If your hard on the throttle with a lot of boost scangauge doesn't show higher intake temps than normal driving (which leads me to believe it's not giving an accurate reading)

- misting at hwy speeds doesn't effect the temperature as much as 30-40 mph driving. Hwy temps are a few degrees cooler, but when misting in stop and go driving temps seem to recover quicker from getting hotter while sitting.

Just some things I found today. I'll have to play with it some more and see what happens.

I checked on the price of distilled water and it's about a buck a gallon. I'd have to see some significant gains to justify spending 3 or 4 bucks per tank on water. Or just use tap water and be prepared to clean calcium deposits every six months...

 

[Mopar1973Man]

- Intake temperature according to scangauge is about 45-50* hotter than ambient temp while moving

This is because the IAT sensor is in the cast iron head that is roughly 190-200*F so the air is pre-heated in the head regardless of the air in the intercooler. So like if its 32*F outside I show roughly 72*F on the IAT sensor. (At full engine temp 190*F) but at a cold start at 32*F the IAT sensor also shows 32*F as well...

- Intake temperature while idling stopped gets about 55-60* hotter.

This is due to the lower RPM's and less air movement around the intercooler. This allows for the air to be pre-heated by the head (coolant temps) even more so. Take notice in the winter time that you can get so really cold temps shown on the IAT sensor when the engine is just started and you start traveling soon after starting... But as soon as the coolant temp comes up the offset is back again... So this just proves this problem...

- If your hard on the throttle with a lot of boost scangauge doesn't show higher intake temps than normal driving (which leads me to believe it's not giving an accurate reading)

Not true... It accurate... The air is moving as fast as the engine can except. So the system is doing its job... But I bet if you where to choke point (greater than35 PSI) on a HX35 I bet the IAT temps would rise then.

There is a error code for IAT over temp and it will cause the engine to defuel... (I'll look it up in the morning...)

I've got a ScanGauge II myself (as shown below). I've checked my IAT sensor against a normal room thermometer and it just about dead on for temps (+/- 1 to 2 Degrees). I bet if you measure the temp of the head where the IAT sensor is mounted you'll find the head temp is the biggest factor. Remember there is a 1/2" NPT pipe plug in the head near the IAT sensor this plug is a coolant passage so I know that coolant temps play a huge role in the IAT sensor temps... But remember you can't move the IAT out of the head either... The problem with this is the ECM can't see the change in temp from the grid heaters in the mornings so the grid heater tend to stay on longer (or until cancelled by speed.) Not to mention if you where to move the IAT sensor to a cooler placement it would effect timing and fueling mapping of the engine... (More so worse MPG's)

 

[millco]

Also,
I would think your mister set up would help more pulling a load up a hill than it would anywhere else. See if you can get a heavy trailer and do some testing climbing a hill hard.
I don't know; but, I wouldn't think you would need the mister cruising down the hwy...

To test if you have the nozzles in the right spot: run down the road with them on while going about 65 mph. Turn them off and stop right away and see where the 'wet' is.

 

[wjbell]

Mopar1973man:

I'm not doubting the scangauge is reading whatever temp the iat sensor is giving it. What I'm saying is that the iat sensor is surrounded by too many factors infuencing a true reading. (cast iron head, water temp, etc)

If scangauge is reporting the same air temp weather crusing down the hwy at 55 or pedal down going up a steep grade it would have to be wrong. There's no way that the intercooler is that good where it removes all the heat out of the intake air created by the turbo. It's more likely that once the engine heats up the intake temp results are altered by the heat surrounding it. And for testing the effects on an intercooler it's kind of useless.

I bet if I put a thermocouple down in the boot before the intake horn I'd see a lot different readings and more fluctuation then on the scangauge.

 

[Dad]

I bet if I put a thermocouple down in the boot before the intake horn I'd see a lot different readings and more fluctuation then on the scangauge.

I'd bet that is correct.

Are you seeing any change in the EGT's when you are misting? On a daily driver, that is the key variable in all this.

If you are running high EGT's, what you have is 90% of the way to having a water injection system.

 

[wjbell]

Also,
I would think your mister set up would help more pulling a load up a hill than it would anywhere else. See if you can get a heavy trailer and do some testing climbing a hill hard.
I don't know; but, I wouldn't think you would need the mister cruising down the hwy...

To test if you have the nozzles in the right spot: run down the road with them on while going about 65 mph. Turn them off and stop right away and see where the 'wet' is.

Yeah, good test ,but I have a small problem. The pump pumps up the line to about 45psi and then shuts off. When the pressure starts to leak down it comes on again. I don't have any kind of pressure check valve so when I shut off the pump all that pressure has to slowly leak out and that means the misters are spraying for about 2 minutes after I turn it off.

Does anyone know where I can get a valve that will only open with a certain amount of pressure? Like if the valve opens and closes at 40psi, and the pump puts out 45psi, when the pump shuts off the valve will shut turning off the misters. Of is there another way I can have an instant shutdown?

 

[wjbell]

I'd bet that is correct.

Are you seeing any change in the EGT's when you are misting? On a daily driver, that is the key variable in all this.

If you are running high EGT's, what you have is 90% of the way to having a water injection system.

I don't have an egt gauge yet. I guess with water injection you'd have to get a tapped intake or something like that. Too bad you couldn't just mist into the stock airbox, but I don't think these tips are fine enough and probably not a good idea to have constant moisture running through your turbo.

 

[wjbell]

Another update

I relocated the pump from the rear of the truck to under the front air dam so it has less distance to pressurize hose. It makes a lot better spray on the misters, also less time for them to leak out the pressure once turned off.

I also redid the bracket holding the misters to more evenly space them.

I was also wondering if I could add a quart or so of rubbing alcohol to the water for better evaporation?

Anyway, the testing continues...

 

[mrlimeysteve]

im no expert but i did use a similar setup on a chev(ahem) motor home for extra cool on big uphill pulls. worked well. i had misters like yours and dindnt do well til i replaced em with a single garden vareity sprayer. it dropped coolant temps from 225 to 185-190 range on long grades. my setup had the advantage of 50 gals of water tho...
i suspect that you may not have quite enough water to cause significant cooling effect with the amount of air that flows through the intercooler. i suppose there is a formula for amount of watr vs. temp change from ambient but damifino where to find it!

 

[mrlimeysteve]

keep us informed as to how the testing goes!

 

[wjbell]

im no expert but i did use a similar setup on a chev(ahem) motor home for extra cool on big uphill pulls. worked well. i had misters like yours and dindnt do well til i replaced em with a single garden vareity sprayer. it dropped coolant temps from 225 to 185-190 range on long grades. my setup had the advantage of 50 gals of water tho...
i suspect that you may not have quite enough water to cause significant cooling effect with the amount of air that flows through the intercooler. i suppose there is a formula for amount of watr vs. temp change from ambient but damifino where to find it!

Wow, really? The reason I didn't go with garden type misters was because all the things I've read say the finer the mist the better. That what you want is the water to evaporate off the thing you're misting, and the evaporation is the process that takes the heat with it. Just soaking down the intercooler with water doesn't do much of anything, at least what I've read.

But I don't know, at hwy speeds maybe I need more water because of the wind evaporating it quickly. I'll have to experiment some more..