Anyone know anything about it, is that something to consider instead of getting a larger intercooler?(short on cash). Any comments on it would help.

Mau

in the tech section.

<ul><li><a href="http://www.audiworld.com/tech/eng22.shtml">http://www.audiworld.com/tech/eng22.shtml</a</li></ul>

There was no temp change. That is the problem with intercooler spray systems. If your intercooler is getting hot, they do what they are supposed to: cool from that temperature back to ambient. Really, at best (and I like this system) all you accomplish is to *guarantee* the nominal efficiency of the intercooler (7x% at stock levels and worse at higher boost).

A more effective means of accomplishing charge cooling (what you really want to do) is to use either an internal, water injection system such as aquamist, or both water spray and injection.

Injection literally cools the intake charge far beyond ANY intercooler (latent heat), and the vapor water (and typically a small amount of alcohol) *acts* as extra octane (knock resistance). (AND, keeps our pesky carbon buildup from happening!)

This lets you run more boost without having to find race gas.

with water. It is not a pretty sight. Water is also not a very good thing since it does take away space from 02. The best thing to do is use a setup that cools the FMIC or the IC pipes using co2 or your A/C.

Aquamist is OEM for several brands, it is more than safe. It has a processor that looks at system status and cuts off flow if there are problems. The orifice is far too small to allow what you are talking about, even if *everything* fails.

Yes, a person could damage the engine with 'hydrolock,' but that was only theory with the very old engine vacuum passive systems and the old windshield wiper pressurized systems. But really all I've seen even with very crude systems was diluted oil and carbon "farts."

using your A/C setup. Just run the A/C and the pipe is cold and making your intake charge very cold.

Cost/benefit(if any) for water spray on the IC is not good. Check down a couple of threads for NOS spray on the IC. Better, and lots safer than injecting NOS, but still not cheap.

Using a/c to cool charge requires mechanical and thermodynamic efficiencies well over 100% to get a gain. Tough challenge.


If you haven't 'chipped', consider starting there.

My $.02.

time. This is a very good setup for drag racing and autox since you just run the car for a few minutes and then shut it off before you make your run.

1. Heat transfer is not going to happen the way you think it is.

A metal pipe in contact over a very small surface area is not going to remove heat in the very short time spans we are talking. Removing heat by conduction is slow to begin with, and it doesn't address the real problem which is the heated air inside the intercooler pipe. The air in the pipe itself is a good insulator.

The article accurately points out that the intercooler is a marginal heat exchanger, but that it is a good heat sink. You want to maximise the heatsink, not conduction. This is why you spray the intercooler with C02/ice, not bathe the piping in a jacket.

2. Pesky laws of thermodynamics.

If you run the AC, the parasitic drag from the AC clutch and the increase heat from the AC heat exchanger will *by definition* use more power than you can possibly gain. The only way this can even come close is to redesign a combination intercooler with the interior AC heat exchanger in a very complex system.

and Her 'Laws'. Much money has been spent (wasted) trying.

All you have to do is freeze the IC line just like you would when using a air to water cooler. You just tee off of the A/C lines and run it back to the main line again.

I agree. That type of system has its place in drag racing and autox, but wouldn't be very good for typical day to day usage. I guess it would be ok for stoplight drag racing, but not much else.

Water injection really is a great way to go. Aquamist systems are very well built, well respected, reliable, and safe. The only bad thing which can happen is you can run out of water at high boost. Obviously that would be nearly catastrophic, but hopefully the knock sensors would catch it before the engine blew itself apart from detonation.

4kq: Have you thought about trying a water injection system on your car? I am still waiting for someone else to take the plunge.

BTW, I still think thats a great IC mister writeup, and a very good improvement to our crappy stock IC's.

-Ian

But is that setup just replacing some of the air with water. Is that why the car does not ping as much?

Water injection lowers temps significantly, which prevents detonation, but also increases the effective octane of the fuel to something which is more similar to racegas.

-Ian

It has been used in NA piston engines, turbocharged and supercharged piston engines and even jet engines to do that: Early Air Force KC-135 tankers needed water-assist on takeoff just to get airborne with a heavy load on a hot day. I watched a KC abort takeoff at about 75 knots when he lost water on one engine (of 4). Barely got the thing stopped on 12,000 ft of runway he was so heavy.

One of GM's first 2 turbo engines was the 215 cube aluminum V8 in the Olds F-85 about '62. (The other was the Corvair Spyder). The Olds still had a 10:1 compression ratio, so they injected a water-alcohol mix to stop detonation. The alcohol was to prevent freezing. Yes, if you ran out of fluid, there could be problems. No computer controls or knock sensors then, but I think there was some mechanical safeguard.

Properly used, and properly controlled, you can 'burn water' and make more power. After all, hydrogen is a fuel and oxygen is the other ingredient you need.

My $.02.

Water has very high specific heat. It'll absorb a lot of heat in the air thus increasing density. Aquamist does make a very good system. The nozzel really atomizes the air very well. It's next to impossible to flood the cylinders. When you combine water/methanol in a 50/50 mix it also increases the effective octane rating.

It also cleans out carbon deposits in the combustion chamber and lowers EGT and engine temp. The benefit more than outweighs the slight volumn of air it displaces.

Aquamist system 1 uses a pressure sensor to activate the pump. They have more advanced contollers which you can set by rpm/boost/load. Cosworth cars comes with Aquamist stock and most rally cars run on this stuff.

I have all the stuff hooked up buy I don't have a place to mount the nozzel properly. You want to mount the nozzle after the IC to increase the temp delta between it's two ends to fully untilize it. On the A4 the end tanks are plastic and I don't feel comfortable tapping it. I also don't want to add another pipe into the rubber. I'm waiting for a FMIC and I'll just mount the nozzel on the tubing. The IAT sensor will pick up the lower temp and increase timing pretty dramatically. John Bass logged his car and you can clearly see much more advanced timing.

A lot of warbirds used it. Esp the ones with forced injection. WI is a great way to lower intake temp and reduce detonation. A much cleaner way than the AC alternative IMHO.

I think that is dingster's hope :)

-Ian

Air Charge Temperature
......................... No misters With misters
Starting temperature.. 105.8°F..... 105.8°F
Ending temperature.... 122°F....... 107.6°F
Rise in temperature.... 16.2°F....... 1.8°F