Compressor after 1 year of precompressor injection.

[cmj]

Check it out. This was with a .6mm jet placed about 12" before the compressor.

[rallimike]

What caused the discloration? Why would water do that?

[cmj]

I bought the turbo used and it already had the discoloration on the blades, other than that it was perfect. The turbo has never been run without an oem filter.

[ben wilson]

That's pretty nasty, I find myself wondering how far can the compressor errode before the effeciency drops lower than a healthy turbo without the water.

[DuMaurier 7]

Originally Posted by ben wilson

That's pretty nasty, I find myself wondering how far can the compressor errode before the effeciency drops lower than a healthy turbo without the water.

And more importantly , whats going to happen with the balance of the CHRA !!?? , will the turbo eventuall destroy itself ??

[busky2k]

After seeing this I'm beginning to think twice about using precompressor water injection...

[hotrod]

Good picture!

Curious what your configuration is --- where did you have the nozzle located, what the spray rate was, and the turn on point?

Yours is a little worse than mine, but you have the same situation where only the blade tips are effected.

On my current compressor I have turned the water spray volume way down and shifted the turn on point to a significantly higher pressure.
We'll see how that works out. I'll pull it out here in next spring probably and take a look at it.

For maximium performance I think the deterioration is probably acceptable if you have no other convenient means to
setup the water injection.
You are working with an undersized turbo and cannot replace it for anyone of several reasons
( like it would move you to a different class but the WI is acceptable).

If your willing to consider the compressor a wear item and spend the $40 odd dollars every year or so to put a new one in.

I still think that circumstantial evidence indicates a good probability that most of us are ending up with
liquid water dropplets running down the inside of the intake duct and that those large dropplets are causing the problem,
rather than the small mist dropplets in the air stream.

Larry

[cmj]

This turbo slowly started pulling less maf voltage, about .1-.2 less than when I first tuned it.

The setup:
Shurflo (pressure switch bypassed, 150psi)
.6mm precompressor
.7mm post intercooler
9psi turn on point
20psi peak boost

[DuMaurier 7]

Is it that the 0.6 jet is too large for that application ?, are you measuring the spray via an HSV , or is it a "dump" type set up ?. I recently ran a set up using a pre compressor 0.9mm jet via an HSV , I did this for about 8 or 9 months and had no problems what so ever , I am now running twin turbos and had planned to use a pair of 0.4mm jets , one in the suction of each turbo , and an HSV to control the delivery to both jets, Now I'm not so sure abou doing that ! :sad: , this is very disturbing !!

[JohnA]

Interesting picture.

What else can you tell us about your setup?
Like engine type, where the nozzle is located (diagram or picture would be very nice!)

I run precompressor injection on a supra twin turbo, and don't dare go for a nozzle larger than 0.4mm
Even this gives me around 10% fuel to water ratio at full boost/full revs.

This ratio can easily go up to 20% if the boost level is reached at 4Krpm.
That's a lot of water.
And you are using more, right?