This is starting to look quite interesting. :smile:

I've booked mine on a hub dyno on the 17th of September, where I will do a few runs testing various W.I. combinations, along with W.I. and fuelling matches too. (lean, normal and rich fuelling with W.I.)
All precompressor of course, 15-10% water/fuel.

These dynos produce very repeatable results, so hopefully I'll have some meaningful graphs afterwards.

I like the idea of a coaxial spray nozzle !!!
That support ring looks nice --- you planning on making those up in various diameters ?

How about a design with a slightly larger outer ring width (broader) designed to be slipped into a flexible hose and held in place by clamping the outside of the hose with a radiator style clamp. That would allow other placements besides precompressor like centrally located in a front mount intercooler tube.

One other possiblility would be to include the feed line into one of the support struts so the support strut brings the hose through the outer ring, with a bulkhead hose fitting on it. That would pretty much elminate hose whip I would think.

Larry

Probably need someone to chime in to give some suggestion as to what was happening. At the sametime, a slightest knock was registered.
Here is a superimposed image of base (faint orange) + Pre-turbo only (full colour)
http://www.aquamist.co.uk/forum/gall...turbo+base.jpg

What caused the a/f ratio to change? injecting about 75cc/min water per 400FWHP.

So what are looking here at?

I can see two AFR lines, three torque curves (without a labeled axis), and two power curves.
Is that right?

I've had some interesting dyno printouts myself this weekend, turns out I need to use MORE water he he... :cool:

I think there are two torque curves, and two boost curves. (The second grey line is so feint that it is almost invisible.)

boost curves?
I see none of those, there is not even a boost scale...

Here is a better one.


http://www.aquamist.co.uk/forum/gall...urbo+base2.jpg

Some further thoughts:

Given the very close correlation between the two runs at lower rpms, I'm inclined to think that the variation at the top represents a genuine change in performance (rather than just measurement error, for example).

The behaviour around 7500 rpm is particularly interesting. Without water injection, the torque and boost diverge and the AFR shows that it richens up. Is this a MAP based system? If so, this might be evidence that the charge temperature is going up at this point (less mass air flow for a given absolute pressure). With upstream WI the effect is there but is much smaller.

A close-up of that region...

http://www.aquamist.co.uk/forum/gall...o+base2mag.jpg

So we're talking here, what, 10bhp extra only at the highest revs?

My dyno printouts are quite different, the precompressor injection effects are striking.
I guess it depends on how much 'over the edge' the compressor is. Well, that's what I thought until I saw further gains with W.I. well inside the compressor's efficient island.

You HAVE to lean the mixture though, or else you lose power (I did that too on the dyno)