Alfa Turbo Nozzle Location
 

I am just about to install my WI system, and was wondering where to place the Nozzle.
I guess just after the Charge cooler would give the best mixing, but that would be before the Dump Valve.

Is it a problem to have the nozzle before the dump valve? In theory when th edump valve opens the WI will be off, but there will probably be a small amount of Mist escape... I will be using a 50/50 mixture.

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Re: Alfa Turbo Nozzle Location
 

All the big droplets won't take the turns anyhow. :-)
For nozzle location, I'd try both right after the CC and before the intake plenum. See what requires the most ignition advance to get power back injecting just water. That position gets the most mist into the cylinder.
If you can life with the whiff of methanol coming through the dump valve is your decision.

For a CC system, you need plenty of water flow though the CC. Get a cheap turbine meter and measure it, if you have not done so. I need both a BOSCH PCA and a Pierburg CWA50 to get to a measly 17 liters a minute. The BOSCH PCA alone only managed 7 liter per minute, the Pierburg pump alone 12 l/minute though 19mm lines.
For your likely 400 to 500HP setup, you need flow rates on the order of 50l or more per minute to drop air temperatures reasonably close to ambient. The best system I have read about flows 60 liters a minute (1000g water per second with a heat capacity of 4 J/g*Ka cooling 400g of air per second with about 1 J/g*K) on a 450HP car and drops IATs to 20C above ambient at race speed.
For a short squirt on the road, things are better as you take advance of the the heat capacity of the water. But this will only help in the first 30 to 60 seconds of WOT depending on the amount of water you have in the CC system.

Re: Alfa Turbo Nozzle Location
 

Thanks for the advice, I dont mind the odd whiff of methanol, and its behind me anyway, as the engine is in a stratos replica.... hence the charge cooler.

I am running close to 500BHP at the moment. Not sure on the charge cooler water flow, I use 25mm lines and a Davis craig EWP 115. I will definately get a flowmeter and see what I get, something I hadnt thought of before...

Re: Alfa Turbo Nozzle Location
 

Got a flowmeter today & hooked it up in the charge cooling circuit. The flow measured was 25L/min, so half of what was reccommended above....

Re: Alfa Turbo Nozzle Location
 

The chap who gets 60l/min out of his EWP115 uses 1 1/4" lines (inner diameter).
But the lines are usually not the issue once inner diameters are large enough. It is the connection pieces and radiators.

The easiest way to find out where the pressure drops accords is to temporality install a manometer in a t-piece and some rubber hose and insert it at the critical locations, that is after the pump (absolute pressure the pumps pushes), before the CC (pressure drop in lines), after the CC (pressure drop in CC), before the pre rad (pressure drop in lines after CC) and after the pre rad. I expect the pre rad being the biggest restriction.
If you find it is the pre rad, consider upping to a pre rad with 32mm connections and use 32 mm to 19mm reducing joint to couple it. Also chamfer all radiuses on rad and CC inlets.
I use 19mm hoses and connections, but the ID of the pre rad barm is only 17mm!! That is way to small.
Those electric water pumps you use are not designed to provide a lot of pressure. You want to drop those pressure drops as much as possible.

Looking at this pump diagram you have a pressure loss of a tad more than 0.5 bar in your CC system.
http://daviescraig.com.au/media/786/...SpecsSheet.jpg


If you leave it as is, it still works, just not as well as it could.

Re: Alfa Turbo Nozzle Location
 

I would also guess that the pre rad is the problem..

Just as a quick test, as I have a spare EWP115, I connected them in series & that increased the flow from 25 to 36L/min. I have 25mm pipes & the tanks on the pre rad are only 25mm wide, so 32mm pipes wont fit, I will look to see if there is a way to improve the flow, but it wont be for a few months, as I will be working away in china... The Space around the pre-rad is also very tight, so not much option to change the pipes. I guess the easiest would be to use a better pump....... but not sure which pumps are better....

Re: Alfa Turbo Nozzle Location
 

This threat contains a few good diagrams of various pumps:
http://mbworld.org/forums/m275-v12-b...ion-pumps.html

The drawn CC circuit resistance curve in there fits your system well as it shows about 0.5 bar at 25 l/min.

You may try to bypass the pre rad with straight pipe to judge the max potential of a replacement.

If you would draw that exponential curve in the CD data sheet for your system, so through the pump curve at 25/l min and extrapolate, it fits well to more than 1 bar of pressure for 36 l/min as provided by two pumps in series.

Re: Alfa Turbo Nozzle Location
 

Its been a while getting round to it, but I now have a Pierburg CWA100 pump. This is installed in series after my Davis Craig EWP115.
Set up like this the:
DC 115 flows 22l/min
the CWA100 35l/min
& both together 42l/min.
The pumps are installed after the charge cooler & before the Pre Rad.
Pressure before the Pre Rad is 4 psi with the DC115, 7psi with the CWA100 & 8.5 with both pumps running, pressures after the Radiator & before the Charge cooler is 0.5, 1.5 & 3psi, so the biggest restriction is the Radiator. I am thinking of getting another CWA100 as I think that will get the flow up even further, probably around 50l/min... Any thoughts on that?