Hi

I'm looking for advice/suggestions/opinions on when it's a good time to add water injection. I'm looking at increasing the power on my 08 STI so am doing the usual downpipe / panel filter / ECUtek re-map stuff but was wondering if it is worthwhile adding some water injection at this point?

One mapper has advised to only use water injection when your turbo is flat out, and the turbo won't be flat out after a re-map.

It was always my impression that the colder you can make the intake charge, the better, regardless of other parameters / ancillaries.

Stu

 

Yip your right on the theory of colder intake temps but if your only planning on the above mods then your nowhere near water injection stage. Water injection can also go wrong. Think what happens if the jets dont work\fail? BOOM

 

its not really advised to have a car set up where its so on the limit it would rely on somthing like water injection to keep it cool enough befor it det and blew up . if you can afford it and its what you want fit it ! its a preventative mesure to reduce intake temps . get a gauge to measure your intake temp and see if its at the stage where it needs lowering then decide . its totaly up to you it wont damage it and it wont me it run 500 bhp .

 

water injection alone looses power

 

why would it lose power ? i allways went under the impression that it will lower the intake temp and thus cooling the air making it more dense and if anything makeing more power if you put it into extreem circumstances ?

 

Doesn't it effectively increase octane as well from releasing extra oxygen or something? I forget the exact science but I've read quite a bit about it over the last few years and it doesn't seem to have any downsides that I can see unless the equipment actually fails or you forget to fill it.

Mate has an aquamist set he's going to be selling me cheap soon.

 

Water Injection - A technical description

 

You will need 50/50 water methanol mix, the methanol also has the advantage of acting as an antifreeze as well as increasing the octane. The increase in power comes from ignition advance and running more boost which the lower charge temp enables you to do. I'm running 340 on my WRX and it may be a next step for me (a bigger turbo isn't). A good safe system fitted by a professional would be closing on a grand.

 

According to Aquamist website you only need 10% methanol to act as anitifreeze. When I talked about it with my mapper he said he would not map with water injection running as if it goes wrong then it could be curtains for the engine. He did agree that by mapping without it running then connecting it up it would provide a benefit but if it went wrong there would be no problem.
Mine is as factory set and comes in at 1 bar actuation but I am looking at re-setting it to 0.7 bar as 1 bar is to high.