A few questions concerning preTurbo water injection

[mrx79]

Hi,
my nozzle is a bit more away from the compressor wheel then on the Picture, but not very much. Maybe 10cm upstream the compressor.

I also thought that spoolup should be increased, but it's definitly the other way around and can be reproduced. Maybe the pure water reduced the turbine power too much. Or the compressor had more work to do because of the additional mass of the water?!. But i'am not sure.

Plugs are NGK BKR7EIX Iridium's and the plug gap is stock (not sure how much). Compression of the engine is around 8.5:1cr.

Also did some recalculations and i think with my activation boost and the 350ccm of water the water to fuel Ratio is pretty high at that rpm. Have to do an exact calculation, but even at redline the Ratio is still 24% water to fuel, so i expect it to be much more at around 3750rpm when it activates.

As RICE saied, the ignition System will have a hard time with so much water without leaner and earlier ignition. And even if the engine pulls, i'am sure there are slight misfires which costs power (maybe this is also a reason for the spoolup issue).

Maybe to try a smaller Jet. ;-)

[parmas]

Originally Posted by mrx79

Hi,
my nozzle is a bit more away from the compressor wheel then on the Picture, but not very much. Maybe 10cm upstream the compressor.

I also thought that spoolup should be increased, but it's definitly the other way around and can be reproduced. Maybe the pure water reduced the turbine power too much. Or the compressor had more work to do because of the additional mass of the water?!. But i'am not sure.

Plugs are NGK BKR7EIX Iridium's and the plug gap is stock (not sure how much). Compression of the engine is around 8.5:1cr.

Also did some recalculations and i think with my activation boost and the 350ccm of water the water to fuel Ratio is pretty high at that rpm. Have to do an exact calculation, but even at redline the Ratio is still 24% water to fuel, so i expect it to be much more at around 3750rpm when it activates.



As RICE saied, the ignition System will have a hard time with so much water without leaner and earlier ignition. And even if the engine pulls, i'am sure there are slight misfires which costs power (maybe this is also a reason for the spoolup issue).

Maybe to try a smaller Jet. ;-)

I am running NGK Heat range 6 on my 8.5:1 compression engine yours is 7 makes it cooler.

Stock gaps are not good for custom setups, recommended gap is 0.6mm or lower. That should give some less stress to the ignition system aswell.

25% seems over but that depends what the engine wants.

[mrx79]

Hi,
did some tests with WM50/50 (by weight) today. But not very much luck.
Car is still slower and makes less power with WI activated.

My parameters are:
max. Boost: 1,25bar (with WI boost drops to 1,1bar)
WI activation at 0,6bar
same ignition advance (aprox. 22.5btdc under boost)
played a bit with afr, but almost no difference between 0,8 and 0,85 lambda.

max. tq /wo WI = 355Nm
max. tq /w WI same AFR =323Nm
max. tq /w WI -5% AFR = 331Nm

I'am still fear that my nozzle is just too big (for my conservative tune/boost levels) as i have a water-to-fuel ratio or 60% at activation boost pressure and it will go down to still 23% at 8k redline.

As a guideline i inject 350ccm of WM mixture on my 1,6L engine.

Anyone any more ideas or should i try a smaller nozzle?!

[parmas]

Originally Posted by mrx79

Hi,
did some tests with WM50/50 (by weight) today. But not very much luck.
Car is still slower and makes less power with WI activated.

My parameters are:
max. Boost: 1,25bar (with WI boost drops to 1,1bar)
WI activation at 0,6bar
same ignition advance (aprox. 22.5btdc under boost)
played a bit with afr, but almost no difference between 0,8 and 0,85 lambda.

max. tq /wo WI = 355Nm
max. tq /w WI same AFR =323Nm
max. tq /w WI -5% AFR = 331Nm

I'am still fear that my nozzle is just too big (for my conservative tune/boost levels) as i have a water-to-fuel ratio or 60% at activation boost pressure and it will go down to still 23% at 8k redline.

As a guideline i inject 350ccm of WM mixture on my 1,6L engine.

Anyone any more ideas or should i try a smaller nozzle?!

You cannot make more power with water/meth injection especially because you are leaving ignition advance the same!

With water + meth injection there is need for ignition advance due to slower burn rate. So to compare you need to max your ignition advance without water/meth injection until you see some power/torque go down and back to 2-3 Degrees for safety then turn on water/meth injection, set 15% if you are intercooled or 25% if you are non-intercooled, put car on dyno, increase advance after 2psi boost where water injection begins. Keep increasing ignition advance until you see a drop in power and again retard 2-3 Degrees. Now compare and you are doing more power and torque with water injection on !

What Air Temps are you seeing?

[mrx79]

Intake Air temperatures are 24-28?C (sometimes 30?C).
First number is at the beginning of the 3rd gear pull, second at redline.

I understand what you say, i'am just not very compfortable with higher ignition advance numbers right now. Don't want to hurt something and i stayed away from high boost much advance tuning until now. ;-)

I think i just have to get warm with it...

the 22.5 is pretty much the safe MBT for that boost Level. Checked that in a series of dyno pulls without WI.

Do you have a (very) rough number on how much more advance i would normaly need or at least which would be definitly too much advance?
Do you think i should see a regain of Tq. by adding a series of +2, +4, +6 degrees? or do you think i would need even more?

[parmas]

24-28C @ 16psi !! What is your ambient temp ?

These are good temps, are these with water injection on?

You will not hurt nothing if you increase 1-2 degree per run. Just don't keep advancing if you see the motor loosing power. Normally 5 Degrees of advance from beginning to end of injection should be needed for a 50/50 mix but that depends how much water/meth you are throwing.

Also you should know that the cooler the air mixture the more advance you need to complete the burn.

Surely advance is an issue here!

[mrx79]

Hi,
these IAT's are with aprox. 20?C ambient temperature. Intercooler seems to be very effective. The IATs are with water injection, but as i saied in my first post's they are not much higher without as well. A few degrees.

My IAT Sensor is by the way at half the way from the IC to the throttle, so the air in the intake runners may be a bit hotter, but under WOT Lambda control and IAT correction based on the IAT sensor Information shows that charge temps are correct.

I thank you very much for your Inputs. I will try a few ignition runs at the weekend.

unfortunatly don't have a smaller nozzle right now but will buy one as soon as i can.

[RICE RACING]

They are all typical results, you will need to reduce the rate of injection fluid by half at least.

[RICE RACING]

You are not loosing any power on the WM50 mixture at all IF you run equivalent boost As this is exactly the difference you have in torque
7% or so ........

2.25 absolute bar / 2.1 bar absolute

= 1.071 * 331 = ~355N/m

Do NOT touch your timing! if you want to try and pick up a bit of power put your boost back to the fuel only setting !!! and then take up my advice to reduce your injection amount, and IT WILL MAKE MORE POWER ON WM50

Regards

[parmas]

Originally Posted by RICE RACING

You are not loosing any power on the WM50 mixture at all IF you run equivalent boost As this is exactly the difference you have in torque
7% or so ........

2.25 absolute bar / 2.1 bar absolute

= 1.071 * 331 = ~355N/m

Do NOT touch your timing! if you want to try and pick up a bit of power put your boost back to the fuel only setting !!! and then take up my advice to reduce your injection amount, and IT WILL MAKE MORE POWER ON WM50

Regards

When injecting water or meth or combined ignition advance must be increased according injection amounts. You will ALWAYS LOOSE POWER when injecting water/meth without increasing advance.

NOTES:

1 . The introduction of water will allow higher boost pressures to be run without detonation. Higher pressures will increase torque

2 . Water Injection allows ignition timing to be more aggressive

3 . Boost does not automatically mean retard your timing

4 . The cooling of potential hot spots in the combustion chamber defeats pre-ignition, the most destructive form of uncontrolled or unplanned combustion

5 . Water injection has a cooling effect on the engine head, valves, and cylinder

6 . Excessive amounts of ignition retard will cause a loss of power and overheating

7 . Water does not burn. There will be no combusting of the hydrogen in the H2O

8 . Injection of 15% water reduces knock better than increasing fuel 4-5 Octane

9 . Injection of water reduces inlet air temperature equal more power


Check this website if any of you say otherwise http://mywintek.com/waterinjection.htm