A few questions concerning preTurbo water injection

[Grant M]

I think Peter has said that with water you increase boost and there is no need to mess with timing to gain power loss IF your ignition is nice and powerful.

I may be wrong

[parmas]

Originally Posted by Grant M

I think Peter has said that with water you increase boost and there is no need to mess with timing to gain power loss IF your ignition is nice and powerful.

I may be wrong

My opinion as a tuner is that when working with engines that want to implement water injection in their setup they have to have a base ingition/fuel tuneup without water injection first. When Max power and torque is achieved without any knock then water injection is intiated.

Water injection is turned on and adjusted as of what the setup needs. Increase boost as the setup needs and when all adjustment is done then ignition timing must be increased 1-3psi further when water injection is initiated accordingly.

If ignition timing is not changed, engine will give better power/torque on top end because of higher boost. If ignition timing is adjusted from turn on of water injection till peak power will result that you gained power/torque from that point till peak power + power increase of boost pressure

[mrx79]

Hi,
just want to give some more updates. After doing some calculations of my WM flow:

until now 350ccm Nozzle: W/F:60%@4000rpm -> 22%@8000rpm
new 140cc Nozzle: W/F:24%@4000rpm -> 9%@8000rpm

i decided to switch to a 140cc Nozzle.
Also switched from 100% Water (frist tests with the 350cc nozzle) to a WM50% by mass mixture.

Results so far (with tune basicaly untuched: AFR=0,8-0,85 / Advance: ~21-22?BTDC @ 16psi)
i experience a similar power loss with the 140cc nozzle as from the 350cc nozzle against the non-WI baseline run.

I then did some calculations on vapour pressure of water&methanol and checked this against my compressor efficiancy. This showes that my compressor is very effective and to keep the water/meth in steam form if once evaporated i have to run at least 18-19psi of boost to keep up the temperature with the rairing pressure after the turbo.
This also not includes the temperature drop from the evaporation.

My calculations showed a too much amount of WM with the 350cc nozzle, so the power loss could be explained, but with the 140cc nozzle i'am in a good ballpark i guess and i'am also below 100% satuation so theoreticaly all the WM can evaporate if enough heat is present.

With this results i'am currently thinking if my setup is just too efficiant for pre-compressor injection - can that be the case?

That something is happening when activating WM is for sure, but what causes the power loss?!

When i assume (just a guess) that most of the WM get's into the combustion chamber unevaporated it will evaporate there under the huge pressure and temps and reduces temps there by a "huge" amount.

Methanol burn slower then gasoline. Water cools the combustion chamber. This would lead to the suggestion that i need more timing. But in fact, i'am still very uncompfortable with even higher amounts of timing.

But this maybe can be a hint that at my current power levels, i just don't need WM injection?!?
By the way, i have to add: i'am running 98roz fuel and the basic compression ratio of my engine is 8.5:1, so fairly low.

[parmas]

Originally Posted by mrx79

Hi,

until now 350ccm Nozzle: W/F:60%@4000rpm -> 22%@8000rpm
new 140cc Nozzle: W/F:24%@4000rpm -> 9%@8000rpm

i decided to switch to a 140cc Nozzle.
Also switched from 100% Water (frist tests with the 350cc nozzle) to a WM50% by mass mixture.

Results so far (with tune basicaly untuched: AFR=0,8-0,85 / Advance: ~21-22?BTDC @ 16psi) DOES THIS AFR KEEPS THE SAME WITH OR WITHOUT WATER/INJECTION?

i experience a similar power loss with the 140cc nozzle as from the 350cc nozzle against the non-WI baseline run. ARE YOU USING A DYNO? IF YES POST DYNO RESULTS.

I then did some calculations on vapour pressure of water&methanol and checked this against my compressor efficiancy. This showes that my compressor is very effective and to keep the water/meth in steam form if once evaporated i have to run at least 18-19psi of boost to keep up the temperature with the rairing pressure after the turbo.
This also not includes the temperature drop from the evaporation.
PLEASE SHARE THESE CALCULATIONS

My calculations showed a too much amount of WM with the 350cc nozzle, so the power loss could be explained, but with the 140cc nozzle i'am in a good ballpark i guess and i'am also below 100% satuation so theoreticaly all the WM can evaporate if enough heat is present.

PLEASE SHARE YOUR CALCULATIONS

With this results i'am currently thinking if my setup is just too efficiant for pre-compressor injection - can that be the case?

That something is happening when activating WM is for sure, but what causes the power loss?! DUE TO SAME IGNITION TIMING VALUES

When i assume (just a guess) that most of the WM get's into the combustion chamber unevaporated it will evaporate there under the huge pressure and temps and reduces temps there by a "huge" amount.

YOUR GUESS IS RIGHT BUT DOESN'T MEAN THAT ALONE = MORE POWER

Methanol burn slower then gasoline. Water cools the combustion chamber. This would lead to the suggestion that i need more timing. But in fact, i'am still very uncompfortable with even higher amounts of timing.

WATER INJECTION IS NORMALLY IMPLEMENTED ON AFTERMARKET ECUs. WHY? BECAUSE THEY CAN HAVE FULL CONTROL OVER FUEL AND IGNITION TIMING. IF YOU ADD A MIXTURE YOU HAVE TO ACCOUNT THE ENGINE TUNE FOR IT NO MATTER IF IT IS STRAIGHT WATER OR METH. I CAN ASSURE YOU THAT WATER INJECTION ALONE WITHOUT TUNING THE BASE MAP IS A POWER KILLER

But this maybe can be a hint that at my current power levels, i just don't need WM injection?!?
By the way, i have to add: i'am running 98roz fuel and the basic compression ratio of my engine is 8.5:1, so fairly low.

YOUR COMPRESSION IS LOW, SO YOU HAVE A CLEAR RANGE TO PLAY WITH ON BOOST. DO A WIDE OPEN THROTTLE RUN AND SWITCH OVER EXACTLY AFTER. CHECK PLUGS AND IF IT IS BLACK YOU ARE EITHER RUNNING RICH OR IGNITION TIMING IS FAR TOO RETARDED. IF YOUR FUEL RATIO WHILE ON BOOST IS 0.85, THAN TIMING IS THE PROBLEM. IF YOU DECIDE TO INCREASE TIMING, FIRST ENRICH THE MIXTURE TO 0.75 THEN INCREASE TIMING ONLY THE LOADS WHERE WI IS TURNED ON. YOU MUST REALIZE THAT WHEN INCREASING TIMING ENGINE SHOULD RUN LEANER ALTHOUGH YOU INCREASED FUEL

[Flr Power]

Originally Posted by parmas

YOUR COMPRESSION IS LOW, SO YOU HAVE A CLEAR RANGE TO PLAY WITH ON BOOST. DO A WIDE OPEN THROTTLE RUN AND SWITCH OVER EXACTLY AFTER. CHECK PLUGS AND IF IT IS BLACK YOU ARE EITHER RUNNING RICH OR IGNITION TIMING IS FAR TOO RETARDED. IF YOUR FUEL RATIO WHILE ON BOOST IS 0.85, THAN TIMING IS THE PROBLEM. IF YOU DECIDE TO INCREASE TIMING, FIRST ENRICH THE MIXTURE TO 0.75 THEN INCREASE TIMING ONLY THE LOADS WHERE WI IS TURNED ON. YOU MUST REALIZE THAT WHEN INCREASING TIMING ENGINE SHOULD RUN LEANER ALTHOUGH YOU INCREASED FUEL

No, no and no. Do not follow parmas "tuning" method. This is clear evidence he needs to get the straight fact. This is old school "tuning".

mrx79, you are not really losing HP with WI and 21-22?BTDC@16psi should be plenty enough timing. With you current power level, you may not need WI if the fuel octane number is good where you live but the set up is getting close to use it.

If you need more power then raise boost to about 20psi, run that 350ccm nozzle and start with low ignition like 12?BTDC and raise it on the dyno run after run until you get to a plateau (while making sure the engine does not detonate) then back up 1-2? to have a super safe tune. Also, make sure you set up and test the WI failsafe properly. This is the most important thing to do unless you do not mind rebuilding.

[mrx79]

Hallo Flr Power,

thanks for your reply to my thread. It's been quite for a while because i had some trouble with my ignition system and afterwards i invested a lot of time in finetuning my new injectors which i had to be done first.

I hope i will manage it this year to do some more tests. But i will get back to it.

Hopefully then with a new/stronger ignition system and will try different thinks, step after step.

[parmas]

Originally Posted by Flr Power

No, no and no. Do not follow parmas "tuning" method. This is clear evidence he needs to get the straight fact. This is old school "tuning". Maybe it is old school but sure it works by facts

mrx79, you are not really losing HP with WI and 21-22?BTDC@16psi should be plenty enough timing. How could you tell 21-22 is good? Cams/compression/plug heat range/coil dwell/charge time/combustion chamber/engine load/turbo/air temperature/engine temperature! These altogether has an algorithm of ? timing an engine needs

With you current power level, you may not need WI if the fuel octane number is good where you live but the set up is getting close to use it. He may not need water injection, but surely there is always an advantage to use water injection. Water injection + METH, is purely an air cooler + octane booster. Altogether need ignition advance to get the power. If he is running 16psi with a 15C air temperature @ 7000rpm maybe yes he does not need water injection at all!

If you need more power then raise boost to about 20psi, run that 350ccm nozzle and start with low ignition like 12?BTDC and raise it on the dyno run after run until you get to a plateau (while making sure the engine does not detonate) then back up 1-2? to have a super safe tune.Have you ever heard of engines tuned "safely" on dyno and ruined at the first run on track?

Also, make sure you set up and test the WI failsafe properly. This is the most important thing to do unless you do not mind rebuilding.AGREED THIS IS IMPORTANT AND most of us forget to take care of prevention

Cheers....