[killerbee]

Water injection as a cooling system expansion tool.

1. add back 5% or more to turbo efficiency
2. pseudo isothermal turbo compression
3. increase WOT performance for increased slope speed, hence cooling performance
4. reduced CAC thermal workload-less cascaded ambient temperature rise
5. lowered intake air charge temp-dense combustion
6. reduced egt, I've heard 200 degrees likely


I would dispense entirely with misting discussion. No misting, just a stream of liquid on the turbo center nut. The turbo is the best source of atomization available. Also negates possible impingement damage to blades, as the stream never touches a high velocity component.

The numbers say it would work, even in the most humid environments, water can be evaporated under 20 psi of compression, it becomes relatively dry, and capable of holding H20 and even methanol. IMO 99 cent washer fluid with some alcohol would be the best.:Thumbup:

Circuit would be series activated. Simple. MAP signal of 25 psi (abs), AND a ECT signal over 225, water miser mode. Could be on a switch to take out the ECT part (performance guys)

Or better a simple on/off timed switch mounted in the cab.

Anyone interested in some development fun?

 

[Turbotug]

I remember reading about it controlling EGT when activated before they were elevated to high or unsafe temps, and IIRC it did little if anything to them when activated later. How are you planing on delivering into the intake stream and only hitting the nut? Most water/meth systems operate a fairly high pressure (200+ psi) and I would imagine a small steam at that pressure would turn to somewhat of a mist. If not, hitting the nut would likely cause a splash effect.

Still sounds interesting and I'd be game to lend a hand if needed.

 

[killerbee]

How are you planing on delivering into the intake stream and only hitting the nut?

Carefully!

The stream does not require but a few psi, and a stream nozzle. That's the beauty of it. Cheap, you can use the WW pump.

Just have to locate the nozzle such that it points centermass, and has no chance of coming loose.:damnit

 

[Turbotug]

Hmmmm...

Just assuming (I know), but at 25psi of boost the turbo is consuming a lot of air and the pre-turbo intake tube with a devise for delivery, that would likely be centered in this tube, would make for rather turbulant post nozzle flow. Would liquid at a low pressure not form into seperate drops and be scattered? Unless you plan to have the nozzel about l l that far from the nut.

 

[killerbee]

the concept here, is that a 20,000 rpm device is going to provide more flash atomization than any misting nozzle could hope to accomplish.

 

[Turbotug]

....reduced atmosphere....:damnit

 

[killerbee]

Where so many pre-turbo installs fail, is the installer throws a conventional misting nozzle on the side of the conduit, and the mist, with significant velocity, just collects and pools on the opposite wall, liquid streams up the intake tube, and hits a blade leading edge whick is going a bazillion mph. Impingement damage.

Do away with trying to mist, it is a waste of time, IMO, for pre-turbo apps

 

[Turbotug]

Any idea on what the temp of the shaft and nut are on the compressor side with sustained EGT of 1000*+? It's cooled by EG and oil that are 200*+, and with IAT of 100*+, I can't imagine it being less than operating temps.

 

[killerbee]

IMO, it is well removed from turbine temps. It is somewhere between IAT (120) and compressed temps (450). That would be my guess. 200-300 degrees? WAG

 

[TheBac]

Interesting.

How much water would this use? Where would you install a tank?

Wouldn't shooting cool water on a hot turbo shaft do something to the hardness of the shaft? I know nothing about metallurgy or heat treating, so bear with me.

What would happen if the water nozzle got aimed incorrectly? Are we talking blown turbo here?

 

[killerbee]

The turbo can handle a lot of abuse. The worst possibility is FOD. Foreign object damage

water coming from underhood, is hot. Ever seen WW fluid boil? Thermal shock is probably not an issue.

I think aiming is critical, in that it must be able to maintain direction, not get bumped out of alignment.

I would worry about how much water later, after it is shown to work or fail. The WW res could be used for now.

But if it works, I was thinking to supplement, use a bag, you know, like the astronauts use?:roflmao:

The List of benefits would include "fewer rest stops"

 

[Turbotug]

IMO, it is well removed from turbine temps. It is somewhere between IAT (120) and compressed temps (450). That would be my guess. 200-300 degrees? WAG

That would definitely help flash liquid to vapor.

 

[killerbee]

I think it is more about what happens on the other side of the compressor. Atomization on the lower micron scale, should be the end result of water hitting the fastest egg beater in the world.

CAC temps drop huge (in theory).

Lets do the calculation to see how much water we need to evaporate, to drop 900 cfm down 150 degrees. We also need some assumptions on ambient air humidity. Need also determine how much humidity is reasonable for intake mixture. I'd guess 90% is the best we could hope for is such a quick mechanism.

Where are the engineers?

 

[Diesel Tech]

The one issue you have overlooked is that the water will collect on the inside of the CAC. Once the mist collects on the fins internal to the CAC it turns back into water so the fine mist your looking for is gone. This has been done for years and the problem has always been the cooling affect of the CAC causes the water droplets to reform. There have been a few people remove the CAC and this works rather well but you need a big water tank because you cannot run out or you just bought a motor if your in a big pull up a grade when she runs dry.

 

[stevebos]

Maybe there is a media other than H20 (ie: liquid nitrogen; like used in cryogenic processes), that in an gaseous state, would provide a comparable cooling benefit and wouldn't reform into droplets when cooled by the CAC?

I don't know; just coloring outside of the lines. :crazy:

 

[Diesel Tech]

Maybe there is a media other than H20 (ie: liquid nitrogen; like used in cryogenic processes), that in an gaseous state, would provide a comparable cooling benefit and wouldn't reform into droplets when cooled by the CAC?

I don't know; just coloring outside of the lines. :crazy:

The most common Gas used to do this is call NOS

 

[stevebos]

The most common Gas used to do this is call NOS

I've understood N20 provides additional oxygen in the combustion process, resulting in more complete burning of fuel and higher cylinder pressures.

Turns out N20 provides an intake charge cooling effect. From the www.nitrousdirect.com website:

"Secondly, as pressurized nitrous oxide is injected into the intake manifold, it changes from a liquid to a gas (boils). This boiling affect reduces the temperature of the nitrous to minus 127 Degrees F. This "cooling affect" in turn significantly reduces intake charge temperatures by approximately 60-75 Degrees F."​

Which leads to another question:

1. How may a N20 system be configured to optimize the intake charge cooling affect?

Thanks for prompting my curiosity; I've learned something new!

 

[Diesel Tech]

How may a N20 system be configured to optimize the intake charge cooling affect?

That my friend is where the trade secrets start to come in. NOS control is a well gaurded secret by most companies that sell kits.

 

[killerbee]

In moderation, there will never be re-condensation of water in the CAC. Old wives tale.

In the event the use of moderation is overlooked, there is no particular "boom" to having partial condensation in the CAC. The CAC survives just fine with an oil film 24/7. Water will do no harm to heat exchange that hasn't already occured with our ingenious egr.

 

[Diesel Tech]

In moderation, there will never be re-condensation of water in the CAC. Old wives tale.

In the event the use of moderation is overlooked, there is no particular "boom" to having partial condensation in the CAC. The CAC survives just fine with an oil film 24/7. Water will do no harm to heat exchange that hasn't already occured with our ingenious egr.

There is no wive tale what so ever, just the nature of it! Water will reform if the mist hits a cool surface. Since the inside of a CAC is filled with fins to increase the surface area and they are cool the mist attaches itself to the cool fins as it travels through the fins. This causes the mist to turn into water droplets and then has to remix with the air once leaving the CAC. If you beleve water does not damage to a CAC I would suggest you take a piece of AL. and leave it in water for several months outside then take a look at it! AL. will and does oxidize. The 2001 - 2004 LB7 had no oil going into the intercooler but the LLY and LBZ do. The oil will help stop oxidation but it still is no good for cooling at all. The hot oil mist deposits itself on the cool fins and collects back into oil just as the water will. The crankcase venting into the CAC was a mandate to meet emmissions not that it's any good for it.