TMIC misters?

[Jolbaru_LGT]

Does anyone have an opinion or experience with intercooler misters? I have the stock TMIC and was wondering if it's worth installing one? I don't track the car... Yet that is. But I take long trips and sometimes it can get a bit hot after a while. Any opinions are appreciated! See DEI Cry02 Intercooler water sprayer is a thing, and no I don't work for or endorse them. Also STI's had them?.. Thanks in Advance. 

[KZJonny]

I would think given you've got a 18 year old stocker, that is good for ~17 psi before it separates at the ends and dies.... Probably better to put the money towards a new OE cooler, or your choice of aftermarket.

You can make your own "bulletproof" kit, which really does work well, but it's still a small OE intercooler.

That said, it's a pretty neat idea, an having steam coming up thorugh the hood scoop when your sitting in traffic heat soaking the IC is probably going to freak someone out!

For the same money, a good turbo blanket might help with heat soak, and somewhat decrease spool time? A little more money for a good heat sheild and reflective tape on the IC ends might also help. These are kind of better since they are passive and work all the time, rather than just when you're pushing a button to spray the IC.

Bag of ice on the intercooler if you are pushing it at the track? 

[Jolbaru_LGT]

1 hour ago, KZJonny said:

I would think given you've got a 18 year old stocker, that is good for ~17 psi before it separates at the ends and dies.... Probably better to put the money towards a new OE cooler, or your choice of aftermarket.

You can make your own "bulletproof" kit, which really does work well, but it's still a small OE intercooler.

That said, it's a pretty neat idea, an having steam coming up thorugh the hood scoop when your sitting in traffic heat soaking the IC is probably going to freak someone out!

For the same money, a good turbo blanket might help with heat soak, and somewhat decrease spool time? A little more money for a good heat sheild and reflective tape on the IC ends might also help. These are kind of better since they are passive and work all the time, rather than just when you're pushing a button to spray the IC.

Bag of ice on the intercooler if you are pushing it at the track? 

Well, I just replaced the old stock TMIC with a new OE stock Subaru one. Apparently it's an upgraded part FWIW. But I put the bulletproof mod on it (a real one mind you, not a bootleg version.) It also has a bug guard I installed over it from this Medium sized SS wire mesh I got from Pegasus. So, it's pretty set. But yeah, stop and go traffic kinda freaks me out, especially being in the Big City. Haven't heard much about turbo blankets, except some people swear by them and others swear against them.

Edited May 3, 2023 by Jolbaru_LGT

[m sprank]

LOL at TMIC water sprayers.  Best joke I have heard all year. 

I would recommend no modding with or on an OEM TMIC.  Its not worth it.  Just because you can make it hold more pressure does not mean it can cool the air charge any better and it is just adequate at stock levels when combined with an engine cover and splash tray.

I used PTP turbo blankets.  They WORK.  But heat soak is heat soak and if your in nutz to butz traffic and its an asphalt jungle heat trap...  nothing will stop it. 

[blackobxt]

In all the years I owned my Sti I can probably count the number of times I used the intercooler sprayer on one hand. The one time I ran it at the track, I used a bag of ice and had a friend pull it out before I got to the burnout box. I can’t really tell you if that was worth it or not lol

[KZJonny]

2 hours ago, Jolbaru_LGT said:

But I take long trips and sometimes it can get a bit hot after a while.

This is probably the place you can do the most with a stock intercooler, which is as described above. not adequate for track use, or much past basic engines mods.

Having the engine cover intact and in place along with the plastic 'skid plate' undertray are going to give it the best chance to such air through the bay and effectively cool the charge.

Turbo, downpipe and up pipe blankets (or wrap) are all going to help keep heat in the exhaust and out of the engine bay. The stock heat sheilds looked pretty good to me as well, but aren't compatible with an aftermarket exhaust system. I have a combination of PTP and Thermal Zero stuff. Build quality and materials on both appear to be pretty much the same, so take your pick.

As msprank said above, in stop and go traffic, not much you can do..... you're gonna heat soak the cooler. Don't stomp on the throttle until after you've been able to move some air through it for a minute to cool everything down.

[Jolbaru_LGT]

Can’t turbo blankets lead to turbo failure?

[KZJonny]

It’s a bit if a cyclical argument.

Turbo blankets keep heat in the turbo and out of the engine bay. So… more heat in the turbo and oil, better performance, faster spool etc….

Probably does break down your oil marginally faster, but if you’re really getting on it often enough to have a red hot turbo, you should probably already have short OCI’s or be dumping your oil after a hard day at the track etc….

Keeping all that heat in the bay means you are potentially heating up the charge air (more knock maybe?) and cooking everything in the vicinity of the turbo. Rebuilding a turbo is cheaper than rebuilding an engine if you’ve got a hot charge and knock, tho I think that would be a fairly extreme case for typical use.

You sort of can’t win, really, so I think that for most people the benefits outweigh the potential harm, most use turbo blankets. Best bet is to use a good quality oil and change it often.

Just my 0.02. I have a turbo blanket and DP blanket and if I need to, I can work (carefully) in that vicinity right after driving around. They really do work to keep things cooler.. change my oil every 5K kms…

Edited May 4, 2023 by KZJonny

[Max Capacity]

What m sprank said. ^

 

[shralp]

See my post from 2020. I decided to use my rear wiper sprayer as a TMIC mister on the track car since I have no need for it. I’ve been using it 3 seasons now with a water/alcohol mix. Would not suggest this for a daily tho… 

 

[KZJonny]

29 minutes ago, shralp said:

See my post from 2020. I decided to use my rear wiper sprayer as a TMIC mister on the track car since I have no need for it. I’ve been using it 3 seasons now with a water/alcohol mix. Would not suggest this for a daily tho… 

 

Nice work, and as you say, best for a track application.

My only question is why bother with any alcohol in the blend for the TMIC mister? The specific thermal capacity of ethanol is ~1/2 of water, so you're providing less cooling the more alcohol you mix into the blend.

Given the ethanol isn't really going to help your track cars' windsheild stay a whole lot cleaner 20 minutes at a time, why not just go 100% distilled water for maximum cooling? I guess it will prevent the tank and pump from freezing, but surely it's easy enough to just empty it in the winter?

Purely curious. I just figure for all that effort, you'd want maximum cooling/L sprayed into the IC.

[shralp]

6 minutes ago, KZJonny said:

Nice work, and as you say, best for a track application.

My only question is why bother with any alcohol in the blend for the TMIC mister? The specific thermal capacity of ethanol is ~1/2 of water, so you're providing less cooling the more alcohol you mix into the blend.

Given the ethanol isn't really going to help your track cars' windsheild stay a whole lot cleaner 20 minutes at a time, why not just go 100% distilled water for maximum cooling? I guess it will prevent the tank and pump from freezing, but surely it's easy enough to just empty it in the winter?

Purely curious. I just figure for all that effort, you'd want maximum cooling/L sprayed into the IC.

I assumed that the evap potential of the alcohol/water mix would be beneficial but maybe not? Definitely out of my area of expertise. Front windshield washers are no longer hooked up.

Edited May 4, 2023 by shralp

[m sprank]

Its a tricky balance.  You dont want to "soak" the intercooler with water as this will block air flow.  You want maximum airflow.  But, at the same time you are trying to cool the aluminum fins to increase overall efficiency.  So, evaporation is necessary for thermal transfer.  

Ii did not read the post and must assume you are trying to maximize potential within a rule set.  Otherwise track car and TMIC dont mix.  Damn rules.  Methanol injection into the intake post turbo is also a power gain (that requires tuning).  Unfortunately, I have experienced too many leaks/clogged injectors/crapped out pumps, etc. to recommend a system. 

[KZJonny]

No. It's all just a calculation based on heat in and thermal capacity of the solution you are using as a coolant. It takes more calories to heat up and evaporate a mL (L, whatever) of water than it does to evaporate a mL of ethanol. So, the cooling potential of water is greater 'straight up' in this situation.

Unless you want to get into some *really* tricky stuff about thermal conductivity of the materials and transfer rates, just use what you've got that has a good specific thermal capacity. (water)

The caveat would be that if you're dumping so much water into the IC that it covers it with a layer of liquid water, rather than a mist which as always picking up heat and being shed from the IC, you might effecitively be working against yourself.

Without numbers on it, my gut says you'd have to be putting quite a lot of water into the IC to have that happen, and if it were the case the best solutions would be to reduce the amount of liquid being injected, rather that adding ethanol to 'thin out' the blend with a more evaporative component.

This is all just sort of chatting physics tho. I'd personally go to straight water A) because it has a higher specific thermal capacity B) while you are right, and the flash point of a blend of ~25% ethanol in water is high,  should you happen to encounter a situation where the ethanol is being boiled out of the (miscible) blend of water and alcohol, and the water is remaining in liquid phase, the result would be a bunch of vaporized ethanol flowing out of the back side of the IC, which is indeedvery flammable. It's pretty unlikely, but physics says it can happen, and I trust the laws of physics.

 

[MitchRoyce]

I don't have direct experience with that exact setup, but I can give you my two cents. First off, if you're not tracking your car and just doing long trips, then you may not need intercooler misters.

Sure, it can get hot after a while, but unless you're pushing your car hard for extended periods of time, the stock TMIC should do just fine. That being said, if you're looking for a little extra cooling power, then intercooler misters could be a good option. I've heard good things about the DEI Cry02 Intercooler water sprayer, and it's definitely worth considering.

And yeah, STIs come with intercooler sprayers as standard equipment, so there must be something to it. Ultimately, it comes down to what you want and how much you're willing to spend. If you think intercooler misters will benefit you and you're willing to drop the cash, then go for it.

[m sprank]

STi intercooler sprayers are a joke.  Its a "bling" add.  Most dont work very quickly. 

Trying to make this simple because there is a TON of physics behind it.  Yes water transfers more heat then alcohol.  But alcohol evaporates faster.  So... the specific heat of alcohol is less and it won't actually cool as much in total.  But, the cooling function is quicker because it evaporates faster.  At the same time a small amount of denatured alcohol will kill any algae growing in your res (that clogs shit up). 

Racers have debated this for years.  You will find one scientist who says "no" and another who says "yes".  I am not a scientist.  But I have had algae grow in under hood water tanks and in my own experience misters work at low speeds better than high anyway and some denatured alcohol sure seems to work better according to my temp sensors.  Sit and let it heat soak, spray and go (0-60mph, WOT).  Temps dropped slightly faster with a mix over pure H2O. 

 

Oh, and the STI manual recommends a mixture of water and alcohol in the OEM system.

 

[KZJonny]

51 minutes ago, m sprank said:

At the same time a small amount of denatured alcohol will kill any algae growing in your res (that clogs shit up). 

This is a very good point. Probably the best argument for including alcohol.

52 minutes ago, m sprank said:

But, the cooling function is quicker because it evaporates faster.

53 minutes ago, m sprank said:

But alcohol evaporates faster.

This does not compute. Evaporation is a function of heat added to a liquid, not vice versa....

You are correct, the physics behind it is medium-complex and would involve surface heat transfer coefficients, etc...  But if you can't get heat into the liquid faster because it has alcohol in it, then adding alcohol because it has a lower boiling point is senseless. You are just reducing the specific heat capacity of the solution, not increasing it's ability to cool.

IF it is possible to get MORE HEAT faster, INTO a solution of ethanol and water faster than straight water, then the blend makes perfect sense. I just don't see how the physics of a blend of ethanol and water make that possible. (sorry for yelling!)

 

As usual I defer to the users manual, and some engineer at Subaru. I didn't know this was a subject that garnered all that much discussion in other circles. Interesting stuff.

 

[Jolbaru_LGT]

21 hours ago, m sprank said:

LOL at TMIC water sprayers.  Best joke I have heard all year. 

I would recommend no modding with or on an OEM TMIC.  Its not worth it.  Just because you can make it hold more pressure does not mean it can cool the air charge any better and it is just adequate at stock levels when combined with an engine cover and splash tray.

I used PTP turbo blankets.  They WORK.  But heat soak is heat soak and if your in nutz to butz traffic and its an asphalt jungle heat trap...  nothing will stop it. 

Is there any type or brand of turbo blanket you recommend? I've still got the original VF40 turbo, the stock splash pan, uncut engine cover, the JDM battery and power brake covers. Most everything the engineers or design team imagined is still there to aid and assist airflow. But now I'm really intrigued about the idea of spending more money! But seriously, I'm thinking turbo blanket, downpipe, actuator blanket, and oil filter blanket. Unless anyone says differently? 

Edited May 4, 2023 by Jolbaru_LGT

[m sprank]

45 minutes ago, KZJonny said:

This is a very good point. Probably the best argument for including alcohol.

This does not compute. Evaporation is a function of heat added to a liquid, not vice versa....

You are correct, the physics behind it is medium-complex and would involve surface heat transfer coefficients, etc...  But if you can't get heat into the liquid faster because it has alcohol in it, then adding alcohol because it has a lower boiling point is senseless. You are just reducing the specific heat capacity of the solution, not increasing it's ability to cool.

IF it is possible to get MORE HEAT faster, INTO a solution of ethanol and water faster than straight water, then the blend makes perfect sense. I just don't see how the physics of a blend of ethanol and water make that possible. (sorry for yelling!)

 

As usual I defer to the users manual, and some engineer at Subaru. I didn't know this was a subject that garnered all that much discussion in other circles. Interesting stuff.

 

So much debate. 

"In this paper, the spray cooling performance is investigated experimentally, and ethanol is used as an additive in water as the working fluid. The reason for choosing ethanol as the additive is that its saturated temperature is about 351 K, thus the mixture of ethanol and water has a lower saturated temperature than water, which can initiate the two-phase regime at a lower inception temperature in order to control the device temperature. The main purpose of this research is to find the optimal volume fraction of ethanol in the mixture to improve the heat transfer performance and to reduce the surface temperature."

"Spray cooling performance using the mixture of water with a reasonable volume fraction of ethanol is much better than that using pure water."

 

A good read:

https://www.sciencedirect.com/science/article/abs/pii/S1290072917306403

 

[m sprank]

35 minutes ago, Jolbaru_LGT said:

Is there any type or brand of turbo blanket you recommend? I've still got the original VF40 turbo, the stock splash pan, uncut engine cover, the JDM battery and power brake covers. Most everything the engineers or design team imagined is still there to aid and assist airflow. But now I'm really intrigued about the idea of spending more money! But seriously, I'm thinking turbo blanket, downpipe, actuator blanket, and oil filter blanket. Unless anyone says differently? 

You can use a turbo blanket and a heat shield.  PTP always worked for me.  Use the WRX/STi model:

https://www.ptpturboblankets.com/collections/subaru-turbo-blankets

I liked to ceramic coat/swain tech downpipes as it is far cleaner, but to each his own.  Actuator blanket?  Do you mean for the wastegate?  Running an EWG?  Even then , dont waste your time/money.  Same for the oil filter blanket.  You want to regulate oil temp, not just keep it in.  Run an oil cooler and then put a heat retention device on the filter???  Reject heat from the filter, dont add it. 

[shralp]

3 hours ago, m sprank said:

Its a tricky balance.  You dont want to "soak" the intercooler with water as this will block air flow.  You want maximum airflow.  But, at the same time you are trying to cool the aluminum fins to increase overall efficiency.  So, evaporation is necessary for thermal transfer.  

Ii did not read the post and must assume you are trying to maximize potential within a rule set.  Otherwise track car and TMIC dont mix.  Damn rules.  Methanol injection into the intake post turbo is also a power gain (that requires tuning).  Unfortunately, I have experienced too many leaks/clogged injectors/crapped out pumps, etc. to recommend a system. 

I knew there would be a lot of debate on this   I guess I'm choosing the "middle way" as I was never able to really determine which route was best in the Water vs. Water/Alc arguement.  I can definitely say that the IC isn't getting "soaked" to the point of blocking airflow, its getting a ton of air jammed thru it on track.  When I get back to the paddock the IC is clean as a whistle and completely dry, obviously plenty of heat under the hood to manage that.  I don't think that the STI nozzles can pump out enough water to impede airflow anyway.  I see that the Flat Irons tuning guys are running the AEM meth kit on their Pikes Peak car but are using it externally to mist their front mount.  The AEM is certainly more complex than my set up and uses high pressure nozzles that really atomize the spray much more than mine do.  For me I wanted to try something that would cost minimal cash, (STI nozzles and a Vibrant Performance washer bottle).  

Actually no rule set on the car, I could run a FMIC for sure and probably should at some point because it is a dedicated track car.  Always lots of looks in the paddock from other turbo folks, "whoah, your running at top mount?!"    They really look at me funny when I tell them I'm currently running a 16G as well!

Edited May 4, 2023 by shralp

[KZJonny]

13 minutes ago, m sprank said:

So much debate. 

"In this paper, the spray cooling performance is investigated experimentally, and ethanol is used as an additive in water as the working fluid. The reason for choosing ethanol as the additive is that its saturated temperature is about 351 K, thus the mixture of ethanol and water has a lower saturated temperature than water, which can initiate the two-phase regime at a lower inception temperature in order to control the device temperature. The main purpose of this research is to find the optimal volume fraction of ethanol in the mixture to improve the heat transfer performance and to reduce the surface temperature."

"Spray cooling performance using the mixture of water with a reasonable volume fraction of ethanol is much better than that using pure water."

 

A good read:

https://www.sciencedirect.com/science/article/abs/pii/S1290072917306403

 

Yes! Logical, polite, scientifically backed debate! Greatest thing ever.

 

The optimal volume fraction of ethanol for the improvement of the heat transfer performance is 4%.

Very cool. No pun intended.

Interesting stuff, tho sadly I do not have journal access to the entire paper. At least from the precis, it seems that the the increased effectiveness of the blended mixture on cooling is due to the alcohol disturbing the surface tension in the water. So it acts as a surfactant, and thus does allow more heat to be transferred into the liquid by disturbing the hydrogen bonding potential of pure water, which is really quite high. The boiling point of ethanol itself is non-relevant to it's efficiency in cooling in this instance. It is it's chemical and bonding properties that add value, not it's thermal capacity.

Also note that in the paper, they are specifically looking at temps below 373K, since this is the point at which water would be a better cooling agent due to higher specific heat capacity. They are talking about cooling electronics, which don't tolerate that temp well:

"However, for most electronic chips, the surface temperature is usually below 350 K to ensure their normal safety operations [18,19]."

I know absolutely nothing first hand about the temperature of the air charge post turbo/pre-intercooler under heavy load/racing conditions. Probably safe to assume it is generally less than 373K. However, above that temperate, the Delta T in the equation pushes the ideal mixture back to where 100% water is the best coolant because of specific heat capacity, since it will boil off immediately, carrying with it the maximum amount of heat. No alcohol needed. (This is analagous to coolant "water wetter", but not the same mode of action.)

So.... since Dr. Google (trusted source?!) suggests that the temperature of an air charge post-turbo can attain nearly 400K, it would be a matter of how hot the IC itself got and how fast it can reject heat to atmosphere. ~27K (=27C) is a rather large temperature variance to play within.... there definitely will be some part of that cooling curve where straight water is going to be the best agent since it won't need help to boil off at a maximum rate. Anything less than that figure, you go back to where the blend is your best bet.

Safe to say that the blend is going to be the best fit to most situations, yes! If you are going hard on a track and running at max turbocharger output temp the whole time, then it swings back to water. Cooling microchips and intercoolers are similar in principal, but not entirely in practice.

I will always graciously stand corrected in the face of good evidence! Thanks for passing on that link.

Or. We all just get huge front mounts and forget about it. 

[m sprank]

I prefer the front mount.  ETS to be exact.  Its far easier than trying to figure out the physics of thermal transfer. 

I have read and heard so much over the years I guess it all boils down to "bro-science".  We ran a not perfectly scientific test once, I fail to recall why, but decided it was better mixing in some alcohol.  When I did find green slime in a STi tank we began mixing in 25% all the time just to make sure it was clean.  IIRC thats when I finally read the owners manual and found the OEM mixture reference.  LOL at myself. 

I played with electronic cooling for a bit too (overclocking).  Peltiers, water-cooling, liquid nitrogen, abnormal mixtures using synthetic liquids supplied my navy nuclear sub HVAC techs.  Stuff like that.  Was able to set a 3D Marks record and get sponsored by EVGA and nVidia.   Before Infamous I owned a small custom PC gaming business.  Almost no one knows anymore. 

If it can be made to go faster, I probably got involved.

[Jolbaru_LGT]

10 hours ago, m sprank said:

You can use a turbo blanket and a heat shield.  PTP always worked for me.  Use the WRX/STi model:

https://www.ptpturboblankets.com/collections/subaru-turbo-blankets

I liked to ceramic coat/swain tech downpipes as it is far cleaner, but to each his own.  Actuator blanket?  Do you mean for the wastegate?  Running an EWG?  Even then , dont waste your time/money.  Same for the oil filter blanket.  You want to regulate oil temp, not just keep it in.  Run an oil cooler and then put a heat retention device on the filter???  Reject heat from the filter, dont add it. 

sorry Wastegate... So really I just need a turbo blanket? The downpipe and uppipe blankets aren't really needed? I mean, I'm fine with spending less money. I have a stock heat shield. Is that good enough?

Edited May 5, 2023 by Jolbaru_LGT

[m sprank]

Blankets are for aftermarket up/down pipes.  If OEM, the heat shields are fine, don't remove them unless they rust free and make false knock.

Edited May 5, 2023 by m sprank