A few questions for anyone who has had experience with water / methanol injection for wrx's:

Is it worth getting?
Average power / drivability gains expected?
Is it best to use a standalone controller or get the Motec to control the delivery and timing increase when in use?
Any possible downsides / reasons why not to run it?
What happens when the tank runs dry? (apart from having to fill it up obviously)
What brands/systems are best to use?
Can ethanol be used instead, just in case we run out of alcohol at a party and the shops are shut?

Thanks

(just kidding on the last question btw)

__________________
Remove hail dents yourself, fast and easy - $25 for a kit. PM me for details
[SIGPIC][/SIGPIC]

Only example known locally is from Waxdass (tode). He has a water/meth system in his STi but I believe it's not fully tuned as yet.

__________________
www.racewars.com.au

it can all be done with motec out of the box, all you need is pumps and solenoids

__________________

Long live the WRC

If your tune relies on it (mostly for ignition timing), best to trigger the water/meth setup with a standalone ecu. In the event of low water/meth levels or pump failure, it'll switch to a failsafe map to save the engine.

if tuned properly, there should already be a trigger for loss of water pressure, with a correction already in place.

__________________

Long live the WRC

Thanks for the replies. I thought it could be done by the ECU, so that be the case the pump, solenoids, hoses and jets etc shouldn't be overly expensive really.

So any ideas what gains are to be expected roughly? Obviously it will be different for each car depending on the existing setup/tune etc. I wouldn't have thought that it would be anything like the gains you would get from Nitrous but then again water & methanol are a shitload cheaper to buy than Nitrous too.

__________________
Remove hail dents yourself, fast and easy - $25 for a kit. PM me for details
[SIGPIC][/SIGPIC]

plan to book the car in for its final tune once soon.
Initial results with the Aqauamist spraying 50/50% water/meth showed AFR's drop by 1.0, thats was triggered at around 45% fuel injector duty.

So plenty of space there to beef up the timing and extract the most out of it.

Triggering the system on or off is at a touch of a button. Which turns on or off an imput to the Autronic SM4 - that alters the map to suit.

I have a 0.4lb/m nozzle tapped before the TMIC and a 1 lb/m into the manifold. Cooling wise it feels like its doing a great job - as the TMIC and manifold are very cold at touch after its been squirting.

good option for a bit of extra poke to my otherwise standard JDM STi (twin scroll) street car.

water is the anti-detonation agent, methanol is the fuel.

so if your car isnt on the threshold of knocking now, water injection will make zero difference and probably reduce its power.

the problem with water is you effectively dilute your air fuel mix, so you have to significantly advance your timing and increase the pay load of fuel to see any real results (hence the methanol).

the problem with methanol is that it has a low burn temp and cannot acheive the same power per cc as dinosaur based fuels.

realistically it takes many hours dyno time to acheive something satisfactory.

if you take a leaf out of the group-b days with water meth injection, they would inject at multiple points of the manifold, including post turbo, pre/post intercooler and even behind the throttle body.

even still, plenty of people whack off the shelf kits on and get a result, they all work, but its never a case of one size fits all.

real world gains i'd suggest in the order of 10-15%, but in the case of physics- use VP109 as your performance ceiling reference point. as its nearly impossible to cause detonation (with intake air temps under 100 degrees), you wont be able to improve beyond that with water/methanol alone.

ie pump fuel tune on the threshold of knock- might make 350hp
race fuel tuned to the hilt, might make 390hp
water/meth will be between those two figures.

__________________

Long live the WRC

well, yeah.

Your easiest option is to upgrade the injectors, and be able to extract more power that way with a good tune/boost.

In my case, iv decided to stick with the stock 565cc's, personally not a fan of how big or decapped injectors behave with response.

Depends on which route you take. If your willing to spend $ on dyno time, which might outweight the cost of actually having a proper water/meth system as Tuna stated - then you will want to choose that route after you've exhausted your options in extracting more power without opening the engine.

If your willing to spend money on a safe system (only buy the Aquamist product), then you can rely on getting proven results with a bit of time spent getting the tune. The Aquamist controller does the rest.

No it wont be as efficient as a Group B rally car system - but you wont be paying as much, drive in drive out. If you do your research. you can get a ball-park figure on what % increase you can expect depending on the ratio of methanol you use and other mods on your engine.

What is your car used for? How much money are you willing to blow on a motor? If your going Motec route - then make sure you also have all the fail-safes programmed in aswell, coz it can be catastrophic if things go wrong.

Whats more cost effective, $/hr with your motec tuner for a ground up map or a effective bolt-on system that pretty much just needs a retune to suit extra igntion/boost when squirting?

I thought your car had water/meth injection as part of Wai's build.

I also had the understanding that spraying a bit of water adds to your compression ratio as its replacing air that would otherwise be compressed.

__________________
Balls.