I'm looking for those that have used water injection for extended periods of time. Qu
 

I'm trying to hear people's experiences with water meth or other cooling methods that start before the supercharger or even after the charger. I would really want to find if someone has used it for am extended period of time and the durability of the system used and how the engine has lasted/ reliability.

For now, im thinking of going to a simple water meth system that squirts pre charger and or post charger but I have some concerns. My concern is first being the supercharger and the longevity of it squirtng straight into it. I would not want to squirt pre charger if I will have to rebuild it in a short amount of time. I understand it will decrease the rebuild intervals but just how short of time?

My next concern is the fact that I'd be squirting straight into the intake stream and have the possibility of one or more of the cylinders not getting enough meth. This would create heat and if I advance timing it would be a dangerous area to be in. So if you have been using this method for cooling whether it be water meth or water how long have you done it and have you seen any extra wear on the charger or cylinders?

I know that port injection would be more safe and efficient but im not trying to go that route as of now.

The only detail about your setup you shared is that you have a supercharger. You mentioned nothing about the type, nothing about your intended control system, nothing about your intended power goals, nothing about your intended vehicle usage.

Give more info and get better answers.

My mistake I didn't think that was needed info as i was just seeking peoples experiences with the setup i described strickly using water meth in any supercharger and wear on a miata engine.

My sc is a hotside mp62. The way I would want to control the meth is either an individual on off system like similar to the AEM or I'd want to control it with my megasquirt and trigger it when temps get to X amount. Haven't worked out the exact temps I'd use it at because I'm still debating using meth. My intended use is street and I'd like to not have to worry about temps when I push the car. Possibly track on the future. All I'm hoping to hear is experiences about using any water meth pre charger or after and how long has your engine/ charger lasted because this would be a determining factor if I go meth. Preferably someone with stock engine like mine but if you have a built one that's fine.

You asked specifically about the longevity of your supercharger. Again all you shared is that you have one.

You also didn't describe a setup. You just said you have a supercharger.

I'm sure you think I'm being difficult but I'm just trying to point out that you can't get useful information with the info you initially provided. Well done on your second take.

No I don't think you are being difficult and now that you have explained how more info could be useful I do understand where you are coming from

I've used water injection now for about a year and a half. The system hasn't failed once in all that time. (edit: slight caveat - after cleaning my nozzles once I didn't put one back together correctly, but it was my error not the systems)

Setup is a diy, 5 nozzles. 1 before sc, one in each port of my intake manifold. I run the pump on / off then PWM a valve to control flow. It has a flow sensor that feeds back to the ecu and that controls switching of the maps.

I really rate having a flow sensor in the system - it makes tuning the flow rates so easy. A single pressure sensor won't give you that information.

I went with individual port nozzles due to distribution worries. My intake manifold is a lot different to a stock manifold. People seem to be able to spray before the manifold and not run into issues but I guess it depends on how close to the edge you are running the tune, how extreme the boost is etc.

No damage to the supercharger rotors from the water.

If controlling with an ECU map it off load vs rpm like a fuel map. Temp sensors tend to lag behind on a pull and peak temps are seen a few seconds after a pull has ended when you are already off the throttle. It doesn't make sense to be spraying the most water / meth then. You want it when the engine is under load.

My favourite thing about my WI setup is its ability to control engine temperatures, most visibly the oil temps on track. I just don't have to worry even on a very hot summers trackday about temperatures, knock etc. I can drive the car as hard as I can for as long as I want and the engine is happy, despite its borderline intercooling.

If you are simply after an x hp increase I can't really comment there. I haven't validated my setup from a power perspective on a proper dyno WI vs no WI or using different injectants, methanol etc. Something for next year I hope.

I don't have long term notes, but one data point on pre-blower injection...

I contacted the folks over at Jon Bond Performance (https://www.jonbondperformance.com/) when I did the DIY rebuild on my M45 looking for some parts. One of the service items I asked about was the special fancy high temp high speed grease to repack the rear rotor bearings. I figured if I was taking it that far apart I should at least clean and repack the bearings with some fresh grease. They didn't (at the time) have it listed on the site but they were kind enough to package some up and sell it to me, but the tech was very confused as to why I wanted it because nobody had ever asked for it before. "The grease should be good for the life of the bearing, unless its washed out by being constantly exposed to pre-blower methanol injection." I told them I'd be doing straight distilled water and they said it should be fine.

Those guys deal with ALL KINDS of blowers under many different conditions, and I don't know how much meth it takes over what length of time but it seemed relevant to the question.

Good info EO2K.

When I had my supercharger rebuilt they used a fancy grease made from various extinct animals.

I did wonder whether methanol would wash it out, and that has been part of the reason I have been a little hesitant to move away from 100% water. Interesting to see the fear validated like that.

The last time i cracked open a squaretop i noticed the EGR system dumps right in front of the valves. Not sure how, but ive daydreamt about running nitrous that way, don't see how water spray would be much different.