Water/Methanol injection

Water/Methanol injection

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Discussion

hotrat

Original Poster:

110 posts

126 months

Thursday 31st July 2014
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Anyone up on it, is it sprayed into the inlet throttle body when the turbo hits a pre set pressure so is only really used when you floor it. is it something that you could use on a daily driver. or would you be filling it up every few miles, thanks.

Boosted LS1

21,183 posts

260 months

Friday 1st August 2014
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I used to spray into my turbo's via welding nozzle tips and it worked a treat. I'd probably use an atomiser if I did it again but maybe the compressors did the atomising for me? My basic system was load and rpm sensitive. When spraying the engine would become quieter, muffled and smoother. :-)

stevieturbo

17,256 posts

247 months

Friday 1st August 2014
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hotrat said:
Anyone up on it, is it sprayed into the inlet throttle body when the turbo hits a pre set pressure so is only really used when you floor it. is it something that you could use on a daily driver. or would you be filling it up every few miles, thanks.
You can spray wherever you want, and under a variety of circumstances.

Yes you could use it on a daily driver and how often you need to refill is a huge variable.
Depends how large your reservoir is and how much and how often you spray.

There is no simple answer, as it's all down to how you implement the system on your car.

hotrat

Original Poster:

110 posts

126 months

Saturday 2nd August 2014
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stevieturbo said:
You can spray wherever you want, and under a variety of circumstances.

Yes you could use it on a daily driver and how often you need to refill is a huge variable.
Depends how large your reservoir is and how much and how often you spray.

There is no simple answer, as it's all down to how you implement the system on your car.
A turbo engine doesn't really use the power that comes with the turbo until you boot it, can that same kind of it's there if you want it power be said of water /meth injection. i know it's not extra power but it is helping with detonation, do you get it mapped into your ecu to get the best or can you run it on a stock ecu if you get me

Boosted LS1

21,183 posts

260 months

Saturday 2nd August 2014
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You can trigger a simple stand alone system with a pressure switch.

stevieturbo

17,256 posts

247 months

Saturday 2nd August 2014
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hotrat said:
A turbo engine doesn't really use the power that comes with the turbo until you boot it, can that same kind of it's there if you want it power be said of water /meth injection. i know it's not extra power but it is helping with detonation, do you get it mapped into your ecu to get the best or can you run it on a stock ecu if you get me
Again, there are many variables.

What exactly are you trying to achieve, and are you in a position where you actually need or will benefit from WI ?

Are you having some sort of tuning or detonation problem you cannot resolve without it ?

You could get it mapped or leave it standard, again, it's another variable depending on what you're trying to achieve.

anonymous-user

54 months

Saturday 2nd August 2014
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The other important consideration if you "map" your engine to take full account of the extra detonation resistance, is what happens should the system fail or run out. Unless you have active knock control and/or flow monitoring that can reduce boost / ignition on a fault, you run the risk of badly wrecking things in those circumstances!

Tango13

8,423 posts

176 months

Thursday 7th August 2014
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Didn't Subaru have a system on one of their cars that sprayed water onto the intercooler at high boost?

TheRealFingers99

1,996 posts

128 months

Friday 8th August 2014
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Tango13 said:
Didn't Subaru have a system on one of their cars that sprayed water onto the intercooler at high boost?
Not just Subaru. Others have used CO2, etc.

But this is somewhat different in effect than water/methanol injection into the inlet tract.

Ive

211 posts

169 months

Friday 15th August 2014
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you can use it on a daily driver. Depending on you full throttle usage, I'd expect 1 to maybe 4l per petrol refill. The latter needing lot's of hooning.
In Spa on track, I manage to use 3l in 20 min. But Spa is a very fast track.
2 things:
Without ignition remapping you will lose power
You will need about 100 to 200ml water/meth 50/50 mix by weight per 200HP per minute of full throttle operation.

On the road in the absence of a Autobahn you won't be able to use WOT for more than a few secionds at a time.
On the road, usage is therefore pretty low.

Evoluzione

10,345 posts

243 months

Saturday 6th September 2014
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stevieturbo said:
You can spray wherever you want, and under a variety of circumstances.

Yes you could use it on a daily driver and how often you need to refill is a huge variable.
Depends how large your reservoir is and how much and how often you spray.

There is no simple answer, as it's all down to how you implement the system on your car.
Stevie, I'm thinking of getting SC to add this to an ECU for me as there is a spare output, do you (or anyone) know if pulsed or constant flow is best and what inputs does it need to take into consideration? Boost pressure and air intake temp I would have thought, injector pulse width maybe?
Not sure whether it's better to go standalone or not at the moment.

anonymous-user

54 months

Saturday 6th September 2014
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You really need to use pulsed control to enable you modify the flow rate of your water/meth injection as engine fuel flow varies. Best option is to try to map injection volume to a certain percentage of fuel mass to try to keep overall AFR somewhat constant.
Unfortunately, due to the relatively slow fundamental PWM frequency of the water injection control valves, accurate mass flow control of your injected mixture is hard. Also, it is quite difficult to ensure an even distribution between the cylinders, especially with upstream single point injection. If you want to maximise output you will need to re-optimise the ignition timing, and in the case of variable distribution, that can be hard to do, unless you are running with cylinder specific knock control trims etc

stevieturbo

17,256 posts

247 months

Saturday 6th September 2014
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Evoluzione said:
Stevie, I'm thinking of getting SC to add this to an ECU for me as there is a spare output, do you (or anyone) know if pulsed or constant flow is best and what inputs does it need to take into consideration? Boost pressure and air intake temp I would have thought, injector pulse width maybe?
Not sure whether it's better to go standalone or not at the moment.
As Max says.

Ideally use 2 outputs. One to enable the pump itself in readyness and the second to control a PWM valve or valves to meter the flow.

In it's simplest form if they can give you a simple flow output relative to injector duty and you can scale this up/down as required...that would be easy.

IMO air temps are sort of irrelevant, as a lot of what the water/meth is doing is in the chamber to suppress detonation. So if tuned to make the most use of this, even if IAT's were cool...turning the WI off would be bad.
People get obsessed with WI and all it is for is to cool charge temps. These are the people who usually dont see gains from using it because they dont bother re-tuning to make use of it.

You could build a MAP vs RPM table same as the fuel table for the PWM solenoid....but it would take longer to fine tune.
A Scalar directly linked to IDC would be the simplest I think and fairly easy to implement.

Even if it could be treated as say a 5th staged injector or something and carrying 5% of the load from the primaries. That type of thing.

Ive

211 posts

169 months

Monday 8th September 2014
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I use an old Aquamist 2c system.
It contains a pump that permanently pressurizes a line to about 7 bar. If you demand flow, pressure drops and the pump is (re)activated by a pressure valve.
To dose the w/m I use a aquamist fast injection valve. I operate it with 50Hz. Flow is controlled by pulse width modulation It is controlled by a spare boost control map of my Emerald ECU. Spray about mirrors fuel flow.
I have 4 75ml/min 0.3mm jets about 10 cm in front of the fuel injectors.
I tried precompressor injection as well. works well, too.
As the Rover K has strongly curved intake runners, you can only do direct port or inject pre compressor. Otherwise the droplets get separated. Big droplets pass the engine with little effect on combustion.
Result is that you need a lot of w/m for little effect.
I run closed loop fueling with a wideband lambda sensor. This allows me to adjust fuel to w/m flow maintaining a constant AFR.


SuperchargedVR6

3,138 posts

220 months

Friday 19th September 2014
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Max_Torque said:
The other important consideration if you "map" your engine to take full account of the extra detonation resistance, is what happens should the system fail or run out. Unless you have active knock control and/or flow monitoring that can reduce boost / ignition on a fault, you run the risk of badly wrecking things in those circumstances!
I used that method on my Turbo Technics Golf 16V, back in the day. A K star box controlled a rail of VR6 injectors and one of it's timing maps was for Aquamist injection. All very basic, but back then 'affordable' SEMs were a distant dream.

Lovely clean piston crowns and valves several thousand miles later when the head had to come off smile