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      11-21-2020, 10:25 AM   #1
m2cWW
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Water Injection Questions

Hey guys! I'm in the process of turning my M2 Comp into a track car. It seems like a water only injection system might be a lightweight, easy mod to gain a solid dozen horses and radically drop temps. Having researched it a bit, I'm only running into one issue. It seems to be a massively complicated field.
That being said, for water injection only, how much will tuning for the WI matter or can we just slap it on the existing tune and call it a day? Moreover, how complicated a system will I need to use? I was looking at aquamist and there are 4 different tiers of complexity in the controller that I cannot for the life of me differentiate. Any help would be vastly appreciated.
Last thing- as regards failsafes. On our cars, which sensors is it best for the failsafe to be triggering from?

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2020 M2 competition, FBO with 1/8" meth bungs available on charge pipe. Straight pipe, manual gearbox. Plenty of other mods irrelevant to the topic. Probably at 510 horse because of crappy CA gas. Not doing e85 because I live in SoCal (no corn around me). Considering meth, seems to be highly illegal though. If I am wrong about that PLEASE tell me. Cheers guys!
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      11-22-2020, 07:09 AM   #2
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If more power is the goal, then you need a tune to get the gains on offer. Injecting water on its own without any tune change is likely to reduce power, unless the new knock index of the fuel air mix is allowing less timing pull, and timing pull was present.

Do you have any issues running on track? If not that seems a lot of work for very little gain.
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      11-22-2020, 10:07 AM   #3
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Quote:
Originally Posted by NISFAN View Post
If more power is the goal, then you need a tune to get the gains on offer. Injecting water on its own without any tune change is likely to reduce power, unless the new knock index of the fuel air mix is allowing less timing pull, and timing pull was present.

Do you have any issues running on track? If not that seems a lot of work for very little gain.
I'm currently running a relatively aggressive tune, but it is not specifically designed for WI if that is what you mean.

I totally see your point- I have no issues on track per se (from the car lol), but I have really dialed in my suspension and tire settings along with my aero and now it feels like the thing is just missing more power.
Thing is, turbos are expensive, e85 is too far away from me to be viable, upgrading the engine components seems like a major surgery (pistons/rods/valves etc), and I'm not looking for another 100 horse, I'm looking for maybe 30-50 at the crank. Maybe the answer is to move lol, get that good European gas.

Have you read anything about interchillers as an option?
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      11-23-2020, 03:18 AM   #4
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Quote:
Originally Posted by m2cWW View Post
I'm currently running a relatively aggressive tune, but it is not specifically designed for WI if that is what you mean.

I totally see your point- I have no issues on track per se (from the car lol), but I have really dialed in my suspension and tire settings along with my aero and now it feels like the thing is just missing more power.
Thing is, turbos are expensive, e85 is too far away from me to be viable, upgrading the engine components seems like a major surgery (pistons/rods/valves etc), and I'm not looking for another 100 horse, I'm looking for maybe 30-50 at the crank. Maybe the answer is to move lol, get that good European gas.

Have you read anything about interchillers as an option?
The interchiller is most useful for drag racing as explained on their website

"Drag Racing
The interchiller is especially useful in drag racing, typically you would perform your burnout and then stage your car, in these circumstances your intake temps are now very high and are only going to get higher as the car has no air flow for cooling, it’s at this point the chiller changes everything. It is not uncommon to have an intake temp after your burnout of 10c (50f) or less on a 30c (86f) day. We have crossed the finish line with intake temps in the low 40’s c (100f) compared to normally crossing at 80-90c (176-194f) on the LSA blower this is a lot of HP being gained!
"

It is not ideal for circuit racing as eventually the system will reach a balance where the heat output from the condensation radiator negates any benefit from the AC cooled charge air. This is simple conservation of energy/ 2nd law of thermodynamics.

As for water injection.

The aim is to "increase octane" rating. As NISFAN said unless you are bumping into timing problems (or design your tune for more advanced timing) then there is little point in water injection.

Typically water injection systems are piggybacks that work in tandem with the cars ECU. This means that usually the two dont talk much to each other and the water injection ECU needs to be capable of making injection decisions on its own.

That is where the complexity (and costs) come from. Just like you can firehose hose fuel into an engine and get some OK performance (at least on older engines, I think the DI engines are much more sensitive) you can do the same with water injection.

But just as with fuel injection more precise control gives better performance. So more sensors, more processing power, and better pump drive circuitry = more control of the water injection process = more and smoother power.

Lastly as the two ECUs dont speak to each other well. You need the water injection ECU to have some protections so that the cars ECU doesn't think water meth injection is there when it is not (otherwise engine go boom).

In conclusion if you are already decated and custom stage 2 tuned there is not much headroom left. Next move is turbos or water injection.

Water injection will likely net you the 30-50 ponies you are looking for but little more. Water-Meth might be a couple 10%s more.

Also consider that you will likely go through a lot of water on a trackday.

Anyways when I looked into this for my last car the plan was to go Aquamist. I would read their manuals etc. If it seems to highlevel for you then it might be time to get a pro in.

The most basic install would be buy chargepipes with meth bungs. Connect these with a Y to the pump (in the trunk), connect that to a reservoir (in the trunk). I seem to remember someone posted a guide of how they did it somewhere on here.
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      11-24-2020, 02:36 AM   #5
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SoCal has a huge amount of E85 stations...
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      11-24-2020, 08:57 AM   #6
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Quote:
Originally Posted by Commanderwiggin View Post
SoCal has a huge amount of E85 stations...
I only wish they were near me lol, there are plenty when I zoom out on the map, but they are all either north or south of me by quiet a ways sadly :/
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      11-24-2020, 09:01 AM   #7
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Quote:
Originally Posted by Megator View Post
Quote:
Originally Posted by m2cWW View Post
I'm currently running a relatively aggressive tune, but it is not specifically designed for WI if that is what you mean.

I totally see your point- I have no issues on track per se (from the car lol), but I have really dialed in my suspension and tire settings along with my aero and now it feels like the thing is just missing more power.
Thing is, turbos are expensive, e85 is too far away from me to be viable, upgrading the engine components seems like a major surgery (pistons/rods/valves etc), and I'm not looking for another 100 horse, I'm looking for maybe 30-50 at the crank. Maybe the answer is to move lol, get that good European gas.

Have you read anything about interchillers as an option?
The interchiller is most useful for drag racing as explained on their website

"Drag Racing
The interchiller is especially useful in drag racing, typically you would perform your burnout and then stage your car, in these circumstances your intake temps are now very high and are only going to get higher as the car has no air flow for cooling, it’s at this point the chiller changes everything. It is not uncommon to have an intake temp after your burnout of 10c (50f) or less on a 30c (86f) day. We have crossed the finish line with intake temps in the low 40’s c (100f) compared to normally crossing at 80-90c (176-194f) on the LSA blower this is a lot of HP being gained!
"

It is not ideal for circuit racing as eventually the system will reach a balance where the heat output from the condensation radiator negates any benefit from the AC cooled charge air. This is simple conservation of energy/ 2nd law of thermodynamics.

As for water injection.

The aim is to "increase octane" rating. As NISFAN said unless you are bumping into timing problems (or design your tune for more advanced timing) then there is little point in water injection.

Typically water injection systems are piggybacks that work in tandem with the cars ECU. This means that usually the two dont talk much to each other and the water injection ECU needs to be capable of making injection decisions on its own.

That is where the complexity (and costs) come from. Just like you can firehose hose fuel into an engine and get some OK performance (at least on older engines, I think the DI engines are much more sensitive) you can do the same with water injection.

But just as with fuel injection more precise control gives better performance. So more sensors, more processing power, and better pump drive circuitry = more control of the water injection process = more and smoother power.

Lastly as the two ECUs dont speak to each other well. You need the water injection ECU to have some protections so that the cars ECU doesn't think water meth injection is there when it is not (otherwise engine go boom).

In conclusion if you are already decated and custom stage 2 tuned there is not much headroom left. Next move is turbos or water injection.

Water injection will likely net you the 30-50 ponies you are looking for but little more. Water-Meth might be a couple 10%s more.

Also consider that you will likely go through a lot of water on a trackday.

Anyways when I looked into this for my last car the plan was to go Aquamist. I would read their manuals etc. If it seems to highlevel for you then it might be time to get a pro in.

The most basic install would be buy chargepipes with meth bungs. Connect these with a Y to the pump (in the trunk), connect that to a reservoir (in the trunk). I seem to remember someone posted a guide of how they did it somewhere on here.
The major sticking point for me in all of that was the ecu talking to the other ecu. It seems like there are a couple of ways to do it (rpm, boost, etc)- are more complex controllers able to read all the inputs fed to it and make decisions based on that info with the limited programming a tuner can give it? Is their software advanced enough to do that? Or is it hoping that my tuner is an exceptionally talented individual?
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      11-24-2020, 11:20 AM   #8
m2cWW
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Quote:
Originally Posted by m2cWW View Post
Quote:
Originally Posted by Commanderwiggin View Post
SoCal has a huge amount of E85 stations...
I only wish they were near me lol, there are plenty when I zoom out on the map, but they are all either north or south of me by quiet a ways sadly :/
According to the .gov website and the Pearson's app, here is my situation lol
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