Yeah, teardrop profile, that would be ideal (tears of joy :lol: )

Just my 2 cents. This will be a significant restriction, with air moving over it at over 100 mph. I see a possible flow issue. I would taper each side to a V.

Also, if it is possible to integrate the mount, such that no cross sectional area is lost at that location (larger diameter chamber that flairs back to normal) that might mitigate head loss.

Which "side" are you referring to?

The ID of the fitting is the same as the ID of the turbo flange.

Just sized the images after anodising. You should be able to see the sides better.

http://www.aquamist.co.uk/forum/gall...ecooler/21.jpg

http://www.aquamist.co.uk/forum/gall...ecooler/22.jpg

When airflow gets to the fitting, it will either have the additional obstacle (restriction) to overcome.

That pic looks nice, a sharp V on the fins, if the backside tapers back to a V the same way, good job. I would just "round" the transition, instead of the flatspot or angle change. If you like, you can widen the fins, in the effort to make them as thin as practical, the idea being invisible to the airstream.

With respect to the ID of the fitting, if you can enlargen it just a bit, in a blended curvature, so that no x-sectional area is lost (from the addition of this beautiful cut piece) that will help minimize head loss as a suction side restriction (the worst kind).

The last thing you want is a failure due to cavitation. that is what I fear. And larger diameter, at the fin location, may help.

Thanks for the advice and useful suggestions. I will thicken up the fins for the next time but will do for the time being.

At present the holder ID is identical with the turbo flange ID. See picture below. There are no breaks - red circle. As far as the air is concern, it cannot see the gap at the intersection. The chamfer on the OD is gone on the anodised version.

I will also round off the tapered fin to minimise any notch developing. It is knife sharp at the moment.

http://www.aquamist.co.uk/forum/gall...ecooler/17.jpg

Like I said before, I'm impressed. Good luck!

I will report the results as soon as I have it. I am keep my fingers crossed and hope the fins hold up. I cannot not rob any more machine room time anymore.

That's a beautiful piece of machining and I look forward to hearing how well it works. As a non-turbo user this is the first time I've looked at the insides of a turbo this closely. It looks as if there is an abrupt contraction just downstream of your new fitting. Is that real, or is it an optical illusion? If it's real I imagine it's there for a reason but I can't see what the reason would be.

that does look fantastic. just wondering about the water feed pipe.

how do you get those small filters in the jets? do you screw the barbed pipe part into the base?
if you did, could you then machine a thread onto the turbo side of the plate, and screw the jet onto it.

so you would have a thread on the outside of here..
http://www.aquamist.co.uk/forum/gall...ecooler/21.jpg

and a cone on the other side to help flow.

then machine a hole into one of the fins to get the water to the jet.

if you see what i mean?

Drew

The water will be channeled into the jet via the rails, possible redesigned the jet jet to accept water on the side, similar arrangement as the side inlet fuel injectors.

The tail of the jet will be a cone shaped nut, as described by you.

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)

We didn't have much time, we just funished tuning the non-WI map and just switch on the pre-turbo as "wait and see". We have to move on to post turbo (will print later) and combined etc.

We may not have inject enough water. I guess we were injecting some 4 litre of fuel per minute so w/f ratio is 150cc/4000cc X 70% DC = 2.6%

Not really a great deal of water. We wil be continuing as soon as we have time.

Any chance of posting your dyno plot?

Yeah, if you run as rich as most people do (looking by the AFRs on that diagram), then to get 700horses you may have to use as much as 4000cc/min.

But where did the 150cc/min come from?
None of the 'normal' Aquamist nozzles gives out so little, right?

As for my dyno graphs, I've got to scan them first and highlight the relevant curves, there are a few runs on each printout.
I'm gonna need another long session though, running more boost, and more water *hint* *hint*

We are running twe 0.3mm jet, one in front of each turbo. At 100% DC, each jet passes 75cc/min of water. Since we are only running 70% fuel dc, so 75+75 x70% = 105cc/min.

Fuel flow is estimated at 4000cc/min. so w/f ratio is 105/4000= 2.6%.

As soon as I have time, I will start increase the jet size. The effect will be more dramatic for sure. At 2.6%, the effect is already very noticeable. Doesn't really know what was going on.

Do you have your dyno plot at hand? If you can't post it, please describe it.

http://www.aquamist.co.uk/forum/gallery/gtart/32.jpg

Ay 2.6% w/f and 11.5a/f ratio, the amount injected is less than a rainy day !! Quick calculation: 0.22% of water of total mass inhaled by the engine.

0.3 jets, are they now available then? I thought 0.4 is the smallest (what I was using)
Also in my experience the 0.4 flows more than the rated 150cc/min. I use up easily half a litre after a blast on the road, or a few dyno runs. And that's injecting at 14psi
my w/f ratio was higher than that, and still was nowhere near enough :lol:

I'd need two things at this stage:

1. the Aquamist turbine gizmo that measures waterflow. I wouldn't dare lean out further without it.

2. that screw-in adaptor to secure the nozzle on a silicon hose. Can't really swap nozzles on the dyno without one.

Let's hope that the Aquamist R&D fund can stretch that far, he he... :wink:

I saw clear power loss when injecting water with stock fuelling (no surprises there, eh?)
I saw clear power gains when leaning the fuelling and using WI on top
I saw greater power gains when injecting water at 8psi instead of 14psi (that WAS a suprise to me, I expected it to be the same or worse)

It took me a few hours on the dyno overall, this is not a cheap sport. I definately need more runs now, knowing what I know.

The 0.4mm jet flow 180cc/min - it has been for a number of years.

1. The flow sensor is available on its own, require a volrtage meter and DDS3 is not used.

2. The adaptor is a press-on type, only abailable for 6mm thick hose - too loose on 5mm hose.

If pre-turbo cooler rate is increased, do you think it is able to use up the excess fuel to gain extra power? If this is the case, pre-turbo has in-build failsafe mechanism.

Richard

I'd swear it is over 200cc/min, 250cc/min perhaps.
But I haven't measured it precisely with the precompressor setup running in real situation, so can't tell for sure.
The voltage is different under those conditions, and so is the pressure difference across the nozzle.
Holding it full boost for 15 or 30seconds in one go is out of the question too, I only have it injecting once both turbos are on-song, and speeds would get silly indeed.

I've swapped it for a 0.6mm now and see how we're doing.

I'm not sure what the thickness of this hose is, it is not silicone though, more like plastic-rubbery. I've managed to hack some traces of thread (courtesy of the Aquamist tap!) on a steel hoseclip, which is secured right on top of the hose hole.
So the nozzle is much stabler now, it should do the trick for a while, until you guys bring press-on adaptors for thinner hoses.

There is always vacuum in that hose, so it cannot pop off, it's just some mechanical stability that it needs

What excess fuel, you have to get rid of all excess fuel for water injection to work properly. That's what I've been saying all along :wink:
You have to run LEAN under full boost.
It's not for the faint of heart.

Can you return the 0.4mm jet and we can test it for you, I will replace it with a new one.

0.6mm: - we have got that far yet, you must be getting some exceptional response, based on the 0.3mm jet we tried.

Excess fuel: - almost all factory turbo cars run rich, so if pre-turbo is so effective to lean-off a/f ratio, then there is little tuning needed to gain power plus point is the in-built fail-safe mechanism?

The power you're making is about 200-250bhp higher than what I'm working on, so my water/fuel ratio is even higher.

Also I am on *stock* turbos, that are outside their efficiency range from 1 bar upwards, so my gains could potentially be higher.
It all depends on HOW MUCH rich we're talking about.
Mine for example runs AFRs of 10.0 at 1.1 bar with stock fuelling.
Simply adding modest precomp WI (trigger at 14psi) on to this setup loses me 10bhp and 10lbft (around 3.5% loss). Boost also drops by 0.05~ 0.1bar with W.I.

If you're already running rich, W.I. makes things worse
Running even richer (after an ECU reset) doesn't even stop it from detonating, mine pulled timing immediately despite the WI (at 8psi) and running rich as hell. Resetting the stock ECU also resets the timing advance to the max values, so first time round the ECU 'hunts' for det, which it found.

I was running 99RON fuel by the way, Tesco's finest, nowhere near race fuel --- I want realistic figures, without fancy FMICs, airfilters, open bonnets etc.

After a few timed runs on the 0.6mm nozzle, the results are not very encouraging.
The difference of water injection in total is minimal 1~2%, barely measureable in fact. You only get on-the-wheels figures with the accelerometer, but using the same stretch of road same day etc gives very repeatable results (not nice curves as the dyno though!)

I thought that maybe the higher boost pressures would be happy with the bigger nozzle, but apparently I went too far.
It didn't even *feel* different either (the 0.4mm nozzle felt different back to back)
Good thing perhaps, because it used around 400cc during 5 runs of 40-100, quite a lot actually...

Fitting the 0.5mm next time, and see how that goes...
(I've measured again the flow of the 0.5mm nozzle, it is 240cc/min with the engine on idle, it would be a bit more with a strong vacuum inside the pipe, wouldn't it?)

I wonder if you need to make some changes on your igntion as well as fuel to make it more effective, with the 0.6mm.

It is interesting that a 0.4mm is more effective. I am sure the vacuum will make it flow more.

Richard

I don't have direct control over the ignition right now, apart from resetting the ECU so that the max advance 'targets' are re-established.
I've got the 0.5mm now, datalogged some runs on the accelerometer.
More boost too, 18-19psi
Haven't transfered the results yet.
I wonder if we can use the pressure formula we use for fuel injectors:

If the ERL pump operates at 10bar normally, we could say that at 1 bar the pressure across the nozzle is 9 bar.
Precompressor, the equivalent pressure would be 10.5bar perhaps.

Any ideas why the above thinking might be wrong?

After entering the results on Excel, here is a summary from the accelerometer datalogging (mainly from 40-100 runs, power estimated at 10mph intervals)

Baseline: car running stock fuelling, stock boost and no WI

Stage1: fuelling trimed to an average 12-12.5 AFR, 7psi extra boost, no WI

Stage2: as stage1, with 0.5mm nozzle injecting at 13psi boost (when both turbos are singing)

Average bhp gains from Baseline to Stage1: 10.36%

Average bhp gains from Stage1 to Stage2: 7.85%

Timewise, on that particular stretch of road (not totally straight and slightly uphill perhaps) 40-100 through the gears, same way every time:

baseline: 9.94secs
Stage1: 8.61 secs
Stage2: 7.97secs

John, those were impressive gains. It seemed that there is a limit how much water can be injection pre-turbo before the gain becomes a loss.

Testing on the sam epiece of road is pretty consist than most people would give credit for. You have spare yourself a great deal of dyno time and cost.

I am not sure if it will help if I lend you a flowmeter, all you need is a DVM to get the flowrate reading, evey little thing helps. PM me your address.

Richard

Oh, it definately works.
I saw that on the dyno as well, there is no question about that.
The devil is in the detail though, I want to know *how much* and *when* so I can optimise the setup for maximum gains with minimal water usage.
The weather helps lately, if it is wet it will not be consistent enough (and bloody dangerous on a public road!)
The dyno gives you a nice curve with AFR info as well, no wheelspin, it's very good.
The road datalogging is good for testing more roughly, to see if you're moving in the right direction.
Flow meter is one, the other is trimming WI according to the fuel injection pulse. At the moment it's not a huge problem because my WI is between 4K and 6.5K so the 'dynamic range' isn't that wide. My water/fuel ratio ranges from 10% to 15% or so (with my basic aquamist system)

I'll send you a PM when I've decided on what sort of setup I'll go for in the near future. Maybe using 2x0.3mm nozzles perhaps...

OK so I read through all 19 pages today...
I went from excited to mixed feelings...
Someone should really update the first page with the more recent results...

People were predicting 30% gains, but in reality you are seeing about 7-10%...

I think I'm going to try it on my car soon.... We'll see how it goes... I have some good ideas.... I love that little contraption you made...

Also could you please tell me what size threading on a bolt, is equivalent to an Aquamist nozzle? I think I already have a pre made tap for an Aquamist nozzle on this used upp pipe I have laying around...

people in the past have predicted the end of the world (more than once!) but I don't feel let down because it hasn't materialised yet. :D

Here is a plot when we run 50% methanol + some timing and fuel trim, the gain is more noticeable - still using the same jet sizes - Port +Pre-turbo.

We will move on to bigger jets as time permits very soon.

http://www.aquamist.co.uk/forum/gall...l+methanol.jpg

Richard, does this run SIX 0.4mm nozzles at the throttle body or is it a typo?

The skyline runs 6x 0.4mm at each port and 2x 0.3mm pre-turbo.




http://www.aquamist.co.uk/forum/gallery/gtart/50.jpg