Intercooler spray or atomizer...

[A930Rocket]

I've been thinking about a system for the intercooler that would spray a cooling solution onto the exterior of the intercooler or internaly to cool the air.

I've seen an external system that had an oval shaped tube that sprayed a fluid, but don't recall what the fluid was (alcohol, windshield cleaner, methanol, water?). Another used NOS as a cooling agent.

I don't recall a system that could be bought or assembled to inject it into the intercooler. Where would the best location be to locate the injector?

Is one system better than the other? Does one cool better than the other? Is one system easier to install over the other? How long will a container of fluid/NOS/etc. last? At the track, sessions can last up to 30 minutes and sometimes longer.

Do they work??

My preference would be to go with a fluid vs NOS using a small aluminum tank up front n the trunk.

What us the best way to trigger it? Using a switch at the gas pedal or linkage?

Thoughts?

[x98boardwell]

356-930 (Chris) has this injection system on his car since he has no ability to have an IC since his turbo motor is in a 356.

He injects right before the boost enters the throttle body. He has a tank that sits up front in the trunk. Pretty slick system. I am sure he will chime in here and explain what he uses. I have this picture from when I went to see his ride... I hope he doesn't mind showing you. Look at the nipple on bottom just before it enters the throttle body. His tank is the circular one in the trunk on the passenger side if I remember correctly.

He claims that is helps immensely and was easy to set-up. His tank lasts as long as his tank of fuel so he fills them out at the same time. I would think this would help with an IC as well since it is still chilled air and our cars love that.

Bryan

[A930Rocket]

Thsnks Bryan. I was thinking someone here had the set up.

Doing some dyno runs, I was amazed at the heat generated and felt by hand on the intercooler. I have a kokeln, but figure this could be used by anyone.

Jim

[356-930]

Originally Posted by A930Rocket

I've been thinking about a system for the intercooler that would spray a cooling solution onto the exterior of the intercooler or internally to cool the air.

I've seen an external system that had an oval shaped tube that sprayed a fluid, but don't recall what the fluid was (alcohol, windshield cleaner, methanol, water?). Another used NOS as a cooling agent.

I don't recall a system that could be bought or assembled to inject it into the intercooler. Where would the best location be to locate the injector?

Is one system better than the other? Does one cool better than the other? Is one system easier to install over the other? How long will a container of fluid/NOS/etc. last? At the track, sessions can last up to 30 minutes and sometimes longer.

Do they work??

My preference would be to go with a fluid vs NOS using a small aluminum tank up front n the trunk.

What us the best way to trigger it? Using a switch at the gas pedal or linkage?

Thoughts?

From Snow Performance's website [http://www.snowperformance.net/products.php?p_cat=324]
FAQ, "3. Do I need an intercooler with Water/Methanol Injection?
Up to approximately 30 psi boost, water/methanol injection (using at least 50% methanol) will provide all the density increase/detonation control needed in most applications. Of course, intercooling and water/methanol injection would provide even greater benefits especially beyond 30 psi boost. Most air-to-air intercoolers are only 50-65% efficient. That means for example, that with 11 psi of boost and the resulting 120°f air charge temperature increase, an intercooler reduces the air charge temperature only 60 degrees. Also, an intercooler will reduce boost 2 - 4 psi. on average."
-----------------------------------------------------------------------------------------------

The big advantage of the water/meth injection is being able to run more advance (to get more HP). This said, my dyno guru warns me pushing the envelope of timing via water/meth cooling is risky in event of a failure of the water/meth delivery under wot/full load. If one gets another 5-deg of timing out of running water/meth and the system fails or simply runs out of fluid, maybe an expensive Kaboom? For insurance against detonation caused engine destruction when running max advance, I'd add a J&S Safeguard knock sensor/control unit. (Wish there was some published and definitive evidence the advertised system performance – sounds good but. . . .)

Do they work? Yes! I don't have an intercooler so water/meth is my only means of cooling the air charge. Haven't blown the non-intercooled engine at 1-bar - yet. I have however pulled timing back to 29-deg at 4000 rpm, no load, 21-deg 1-bar boost ever since dyno guru scolded me.

System was easy to install. It has its own trigger/control mechanism via a pressure sensor built into its computer controller handling the pump. Fluid flow onset pressure and rate of flow ramps with boost. Both are adjustable on the units electronic control module.

Amount of fluid consumption is a function of engine size, and boost. I go through 2-1/2 qts. for every 12 gal of gas when misbehaving on the street. If you choose to go with a water/meth injection system, install as large a reservoir as you're comfortable with. A gallon/1/2 hr. on track? Don’t know but running out of fluid is not recommended.

I've been advised methanol is not compatible with aluminum. Use either plastic or stainless.

I have no experience with any system other than Snow. Snow has knowledgeable customer service personnel and the owner has 20+ years experience injecting/testing supercharged/turbocharged engines. Wouldn’t hurt calling and jawing with one of the tech staff.

My 0.02 cents worth? Knowing what I do about these systems, it’s ok to use them to push the timing HP envelope for a street rod or 1/4 –mile drag car. And, if you are looking to cool the charge air for added engine safety on the track, water meth is ok too. But, if you're looking for max HP via timing via water meth for sustained periods of boost on the track I'd think twice.

PS: Bryan – You can post pix of my engine anytime you wish – thanks!
Yes, the cylinder in the upper left of trunk is the 2-1/2 qt. water/meth reservoir.
Chris

Photo of water/meth pump.

[A930Rocket]

Thanks Chris. I'm not looking for more HP. Just safe HP. I'm putting out 400 rwhp and as hot as the IC got at the dyno, I figure a little more cooling will help.


Timing will not be advanced.

I'll get with Snow and see what they have.

[x98boardwell]

Chris, Thanks for the comments. You never know how some people are with their cars, but I didn't think you would have an issue. Too beautiful not to show off.

When you get a chance will you PM me the place that rebuilt your fuel distributor, how much, turn around time and anything else that you think I should I know. I'm thinking about sending mine off.

Thanks,
Bryan

[930gt-40r]

356-930
What do you think about the individual per cylinder injection systems? I did one on a Subaru with a Perin performance system (has its own splitter and 4 nozzles).
Im thinking about it on my 930, but I am out of money for now.

[356-930]

Originally Posted by 930gt-40r

356-930
What do you think about the individual per cylinder injection systems? I did one on a Subaru with a Perin performance system (has its own splitter and 4 nozzles).

Early Corvette fuel injection systems were mass flow devices. Next came individual port and now, direct injection is the ticket. While I'm truly not qualified to answer your question, I don't believe individual cylinder cooling of charge air would be of significant added benefit. Snow's water/meth injector nozzle (probably 225ml/min for your 400HP engine) is placed in the airstream before the throttle body is fed with fluid at 150-PSI. Fluid exits the nozzle fully vaporized and should get thoroughly mixed in the pressurized airstream.
This said, I wouldn't hesitate to ask a tech at Snow their opinion and if they agree with my seat of pants assessment, what is their basis of their opinion. And, I'd call Perin, ask them the same question. Must be a reason Perin went with individual v mass injection.

[Craig 930 RS]

I'd make certain of these things:

1) The fan is pulling as much air as possible through the IC - and not around it
2) .... Via shrouding for the IC

Otherwise, the liquid won't be drawn through the IC body and you'd effectively be wasting time & effort, IMO.

[purplehaze]

Chris - Beautiful engine and conversion! I'm impressed you stuffed a 930 engine into a 356, plus the injection system.

Jim -

As I understand it, another benefit of the water/meth injection is repeatability or consistency in power, despite temps. Meaning, less HP loss if it's 95 degrees. It can increase HP a tad, but the biggest gain is that you don't lose much. I'm interested as well in doing a similar setup.

As he's local, I spoke with Mark DaVia. He and Drew Wikstrom won Tire Rack's "One Lap of America" thing for the past 5 years straight. I think Mark installed a system from http://www.aquamist.co.uk/ and says now he loses 7 HP due to heat, versus 70 before the install. Not too shabby. I can feel the loss in power from sitting (heat soak) or after a few laps in hot weather. It's just not the same as when cold. My goal woudl be to have the same power regardless of conditions.

These systems seem economical, and increase the density and cool the intake charge. I really don't understand why more shops don't offer them.

The snow system looks good/similar. I know the aquamist system has a warning if the water/meth is low, and can limit boost/ignition. Nice safety device. And the water/meth only flows under boost, so it's not like it's always spraying.

We'll need to re-tune for boosted conditions after adding injection.

Cheers -

[356-930]

Originally Posted by purplehaze

Chris - Beautiful engine and conversion! I'm impressed you stuffed a 930 engine into a 356, plus the injection system.

Jim -

As I understand it, another benefit of the water/meth injection is repeatability or consistency in power, despite temps. Meaning, less HP loss if it's 95 degrees. It can increase HP a tad, but the biggest gain is that you don't lose much. I'm interested as well in doing a similar setup.

As he's local, I spoke with Mark DaVia. He and Drew Wikstrom won Tire Rack's "One Lap of America" thing for the past 5 years straight. I think Mark installed a system from http://www.aquamist.co.uk/ and says now he loses 7 HP due to heat, versus 70 before the install. Not too shabby. I can feel the loss in power from sitting (heat soak) or after a few laps in hot weather. It's just not the same as when cold. My goal would be to have the same power regardless of conditions.

These systems seem economical, and increase the density and cool the intake charge. I really don't understand why more shops don't offer them.

The snow system looks good/similar. I know the aquamist system has a warning if the water/meth is low, and can limit boost/ignition. Nice safety device. And the water/meth only flows under boost, so it's not like it's always spraying.

We'll need to re-tune for boosted conditions after adding injection.

Cheers -

Thanks for your kind words Jim.
The Snow unit comes with an optional reservoir low level sensor. It also controls fluid flow onset and rate, both user adjustable. Don't know whether it has the ability to limit boost/ignition.

As noted earlier in this thread, tuning for max HP by ability to advance timing with intro of water/meth is dangerous. If one dyno's an engine it's done presumably with optimum ambient air conditions. As one pushes a turbo engine, the boost air temp raises, especially on sustained boost on track. The water/meth will, as you note, help maintain boost air temp closer to optimum ambient, a power saving act but not a power boosting event. If one tunes for increased HP by use of water/meth injection one needs to be aware of what can/will happen if the injection goes away at the wrong time.

Below is copy of technical information on fuel combustion in a turbo engine with data addressing Specific Heat and Latent heat of various media. It helps to understand what's going on in a gasoline engine combustion event and what influences it. (I understand just enough of it now to understand why I wasn't valedictorian of my class.) This said, Specific and Latent heat of water and methanol appear to be good things to introduce into a turbocharged engine - in appropriate and controlled amount.
--------------------------------------------------------------------------------------------
Application Note: You CAN be too Rich
By Klaus Allmendinger, VP of Engineering, Innovate Motorsports

Many people with turbochargers believe that they need to run at very rich mixtures. The theory is that the excess fuel cools the intake charge and therefore reduces the probability of knock. It does work in reducing knock, but not because of charge cooling. The following little article shows why.

First let’s look at the science. Specific heat is the amount of energy required to raise 1 kg of material by one degree K (Kelvin, same as Celsius but with 0 point at absolute zero). Different materials have different specific heats. The energy is measured in kJ or kilojoules:

Air ~ 1 kJ/( kg * deg K)
Gasoline 2.02 kJ/( kg * deg K)
Water 4.18 kJ/( kg * deg K)
Ethanol 2.43 kJ/( kg * deg K)
Methanol 2.51 kJ/( kg * deg K)

Fuel and other liquids also have what's called latent heat. This is the heat energy required to vaporize 1 kg of the liquid. The fuel in an internal combustion engine has to be vaporized and mixed thoroughly with the incoming air to produce power. Liquid gasoline does not burn. The energy to vaporize the fuel comes partially from the incoming air, cooling it. The latent heat energy required is actually much larger than the specific heat. That the energy comes from the incoming air can be easily seen on older carbureted cars, where frost can actually form on the intake manifold from the cooling of the charge.

The latent heat values of different liquids are shown here:

Gasoline 350 kJ/kg
Water 2256 kJ/kg
Ethanol 904 kJ/kg
Methanol 1109 kJ/kg

Most engines produce maximum power (with optimized ignition timing) at an air-fuel-ratio between 12 and 13. Let's assume the optimum is in the middle at 12.5. This means that for every kg of air, 0.08 kg of fuel is mixed in and vaporized. The vaporization of the fuel extracts 28 kJ of energy from the air charge. If the mixture has an air-fuel-ratio of 11 instead, the vaporization extracts 31.8 kJ instead. A difference of 3.8 kJ. Because air has a specific heat of about 1 kJ/kg*deg K, the air charge is only 3.8 C (or K) degrees cooler for the rich mixture compared to the optimum power mixture. This small difference has very little effect on knock or power output.

If instead of the richer mixture about 10% (by mass) of water would be injected in the intake charge (0.008 kg Water/kg air), the high latent heat of the water would cool the charge by 18 degrees, about 4 times the cooling effect of the richer mixture. The added fuel for the rich mixture can't burn because there is just not enough oxygen available. So it does not matter if fuel or water is added.

So where does the knock suppression of richer mixtures come from?

If the mixture gets ignited by the spark, a flame front spreads out from the spark plug. This burning mixture increases the pressure and temperature in the cylinder. At some time in the process the pressures and temperatures peak. The speed of the flame front is dependent on mixture density and AFR. A richer or leaner AFR than about 12-13 AFR burns slower. A denser mixture burns faster.

So with a turbo under boost the mixture density raises and results in a faster burning mixture. The closer the peak pressure is to TDC, the higher that peak pressure is, resulting in a high knock probability. Also there is less leverage on the crankshaft for the pressure to produce torque, and, therefore, less power.

Richening up the mixture results in a slower burn, moving the pressure peak later where there is more leverage, hence more torque. Also the pressure peak is lower at a later crank angle and the knock probability is reduced. The same effect can be achieved with an optimum power mixture and more ignition retard.

Optimum mix with “later” ignition can produce more power because more energy is released from the combustion of gasoline. Here’s why: When hydrocarbons like gasoline combust, the burn process actually happens in multiple stages. First the gasoline molecules are broken up into hydrogen and carbon. The hydrogen combines with oxygen from the air to form H2O (water) and the carbon molecules form CO. This process happens very fast at the front edge of the flame front. The second stage converts CO to CO2. This process is relatively slow and requires water molecules (from the first stage) for completion. If there is no more oxygen available (most of it consumed in the first stage), the second stage can't happen. But about 2/3 of the energy released from the burning of the carbon is released in the second stage. Therefore a richer mixture releases less energy, lowering peak pressures and temperatures, and produces less power. A secondary side effect is of course also a lowering of knock probability. It's like closing the throttle a little. A typical engine does not knock when running on part throttle because less energy and therefore lower pressures and temperatures are in the cylinder.

This is why running overly-rich mixtures can not only increase fuel consumption, but also cost power.

[A930Rocket]

Craig

I have the IC fully shrouded and the AC condensor removed as well.

I am thinking about adding a fan under the IC to help, but would it pull more or less than the stock fan?

I'd make certain of these things:
1) The fan is pulling as much air as possible through the IC - and not around it.
2) .... Via shrouding the IC.
Otherwise, the liquid won't be drawn through the IC body and you'd effectively be wasting time & effort, IMO.

[A930Rocket]

Managing the higher intake temps from boost and higher ambient temps at the track is the big goal. Like you, I can feel I'm down on power when it's hot out.

My thoughts are that I'm not going to advance my timing, the system is used only under boost, is triggered by a switch at the pedal when floored (would a short delay help help here and how would it be done?), and for the track only.

Chris, you say methanol is not compatible with alumnum. What does it do? I'm not sure where I could place an injector, but on the IC somewhere on the outlet side.

Chris - Beautiful engine and conversion! I'm impressed you stuffed a 930 engine into a 356, plus the injection system.



Jim -



As I understand it, another benefit of the water/meth injection is repeatability or consistency in power, despite temps. Meaning, less HP loss if it's 95 degrees. It can increase HP a tad, but the biggest gain is that you don't lose much. I'm interested as well in doing a similar setup.



As he's local, I spoke with Mark DaVia. He and Drew Wikstrom won Tire Rack's "One Lap of America" thing for the past 5 years straight. I think Mark installed a system from http://www.aquamist.co.uk/ and says now he loses 7 HP due to heat, versus 70 before the install. Not too shabby. I can feel the loss in power from sitting (heat soak) or after a few laps in hot weather. It's just not the same as when cold. My goal woudl be to have the same power regardless of conditions.



These systems seem economical, and increase the density and cool the intake charge. I really don't understand why more shops don't offer them.



The snow system looks good/similar. I know the aquamist system has a warning if the water/meth is low, and can limit boost/ignition. Nice safety device. And the water/meth only flows under boost, so it's not like it's always spraying.



We'll need to re-tune for boosted conditions after adding injection.



Cheers -

[purplehaze]

I like the simplicity of the pedal-actuation, but I bet even that Snow unit is vac activated. Set it and it'll take care of itself.

Pure methanol is corrosive to aluminum. Others run water/meth (or water and rubbing alcohol, less $$), which helps. If I do this as Chris did, I'll just run one injector into the throttle body. The meth evaporates immediately but cools the charge.

[356-930]

930Rocket: As Glenn notes, pure methanol corrodes aluminum. I don't believe that in the quantities and duration of injection into the airstream of the IC any detectable corrosion will occur.
The installation instructions will show installation of the nozzle assembly into the airstream somewhere in front of and perpendicular to the throttle body. Some install it in the rubber boot connection between the IC and TB. (I opted for a cleaner install metal to metal.)

Glenn: I don't believe the meth evaporates. I believe it vaporizes along with the water. Whether it separates from the water during the combustion cycle is a question I can't answer but if it does, it burns/combusts as does the gasoline. All by itself, pure methanol is a great 4-cycle engine fuel.
It is technically interesting that (according to Snow's tech info) the mixture of 50/50 meth/water produces more cooling capacity than pure water or pure meth.
Before running rubbing alcohol, I'd look at it's specific and latent heat capacity. May save $$$ at the cost of cooling.

[A930Rocket]

Sounds like a good idea. Can rubbing alcohol be bought by the gallon? Where? I'm thinking for the track, to have a one gallon cell that I can check on when I refuel (and at 3 mpg, that's too often!).

Edit. Just read Chris's post. Where can you get methanol as well. I saw that Snow has their own product, it's probably not cheap and certainly not handy.

I like the simplicity of the pedal-actuation, but I bet even that Snow unit is vac activated. Set it and it'll take care of itself.



Pure methanol is corrosive to aluminum. Others run water/meth (or water and rubbing alcohol, less $$), which helps. If I do this as Chris did, I'll just run one injector into the throttle body. The meth evaporates immediately but cools the charge.

[thedge]

Its pretty common to use windshield washer fluid, as that has alcohol in it.

[purplehaze]

Chris - THanks for the clarification. You're right, I didn't mean evaporation. Damn cold meds. Interesting point regarding the cooling affect of alcohol to meth.

Thanks for sharing Klaus' points on richness. I think I actually understand him. I've found the same thing on the dyno; I was trying to be 'safe' and keep things rich and was giving up HP as a result.

What sort of mixture adjustments did you have to make to compensate for the injection, Chris?

[purplehaze]

Originally Posted by thedge

Its pretty common to use windshield washer fluid, as that has alcohol in it.

Are we still talking injection here , or after the liquor stores close down.....?

[930gt-40r]

Originally Posted by purplehaze

Are we still talking injection here , or after the liquor stores close down.....?

It turns out that bottle of 151 has a dual purpose....sweet!