Hey guys, I was wondering if there are any negative effects on the engine using water/meth injection. My friend has it on his srt4 to keep the knock down when turning up the boost on 91 octane (the highest we have in california) It works of course, he uses windshield washer fluid, and has found it to work best for his setup. Overall is it a good idea? Thanks

It depends on how it is used and controlled. If you have some sort of precision controler and use the correct mixture, you can actually utilize the properties of the alchohol to create more power. In a sense, it can be compared to a shot of nitrous but safer on a boosted motor. It can be used as knock control, but my own personal opinion, as some others may or may not share, is that when used for such a purpose. It is nothing more than a poor excuse for poor tuning or a poor combination of parts. To small of an intercoller or turbo for example. I understand that your location limits the octane rating of your available gas, but cooling the intake temps or slightly retarding the timing may provide the same results while actually increasing the longevity of the life of the motor. If it's used to cover up another problem, then that problem still exhists, and will eventually be the downfall of the engine. In simple terms: mechanical failure.

I totally understand what you are saying about the poor tuning situation. But in my situation, that is the only way i can boost over 14 or 15psi on pump gas. 91 is the highest you can get in california anywhere except at the drag strip and damn that is expensive and over an hour and a half away. But no matter how pin point tuned the engine is, which i am going to put alot of time in to doing by the way to get that air fuel ratio stuck on 11.8-12.1 and the timing good, it is still always going to start knockin over 15 psi. You know what i mean?

I understand exactly what you are saying. In your case water meth may be your only option. I would highly suggest against using washer fluid though... It works for the most basic of the horendous hillbilly set ups,but there is no consistency to the mixture. What might be safe from one bottle could be destructive in the next. And there's the fact that your pouring a soap solution into your motor... There are a number of venders available that can be found with a web search that sell the correct components at reasonable prices. Buying the alchohol in %100 pure form from a industrial suplier and mixing it yourself is another option. My suggestion would be to find some sort of detonation detection (there was a thread about that somewhere around here not to long ago-search for "det-cans") and head to a dyno and judge your results before you purchase the equipment. You may find better results than you expected. If you need such a thing then explore your options and do some research. Make sure your engine can handle the loads, and if possible, tune the water/meth injection such a way that utilizes its maximun potential.

Is the only way to tune the water/meth injection by which nozzles you purchase? And other than alcohol mixes, is distilled water the only other way to go?

Every system is different. Your better ones use a control module and injector(s) that operate similiar to fuel injectors. The basic setups only have a spray nozzle and vary the pressure. It will be up to you to decide what you need. A call to a local dyno shop would help lead you in the right direction. Distilled water is what I prefer to use to mix, but pre-mix's are available also. Do some searching and talk to your tuner. Nobody knows what your car is capable of but you, therefore you need to make the final decision.

Well, my friend that is using the washer fluid in his srt4 has the type that runs off of vacuum pressure. when it hits 15psi, it starts injecting. He paid 300 for the kit. Is that a better one or basic?

Originally posted by quicksilver99
it can be compared to a shot of nitrous but safer on a boosted motor.

haha, not really

go with water/denatured alcohol. Primary use is knock control. More power will come from more timing advance. Few ways to control knock and thats up the octane (alcohol) retard the timing (and lose power) or cool the air more (which you do). It's also thought of as 'in-cylinder-intercooling'. Back in the day I was pushing 21psi on 91 octane and it ran sweet with a makeshift aquamist kit (hobbes switch, check valve, pump, tank and aquamist nozzles) Tap it after the intercooler.

good site to check out:
aquamist.co.uk

well, i took a look at that website, I hope I am missing something because it says "WI system1s kit (race pump) $642.40 USD." If that's correct, they are out of their minds! haha. I'm not building an all out race car. I'm building a daily driver, but capable of mid to high 11's at the track with slicks.