toddk911

Agree. I have read about a lot that use before and after IC and some do both. Therefor the injection point before the IC acts as an IC cooler/sprayer and then the 2nd point right before the throttle body. It's called a dual stage WI system.

Charlie944

John, the boost activation switch I have is attached to the fuel rail. Are the failures due to excessive heat?
The 924 Carrera GT scoop on the hood will provide a bunch of air flow on that area where I have the boost activation switch at.

In the last picture the brass device with the wires is the pressure detector switch that controlls the light in the cabin telling me everything is working.

fast951

Charlie, I used the wrong terminology, I am referring to the unit in the above picture. It's the switch that detects the pressure. While I'm warning you about stuff, don't assume that if the same switch does not give you a warning, everything is ok. You could have a clogged nozzle, lots of pressure in line but no flow.
I hope I don't come across as picking on your kit, I'm not. I just spent lots of time evaluating various systems, talked to various parts suppliers while designing a fail-safe kit. I'm just raising yellow flags so you are aware of the possibilities.

Matt Sheppard

Hey John:

Is there any better solution? Perhaps using a flow-meter as a fail-safe in conjuction with the pump duty cycle (something like that)? I too worry about clogged nozzles and how to detect such a failure - especially in a port injection scenerio (one cyl. clogs - even partially - and the main flow still reads 80-90% flow and poof! you burn a valve). Then what if a rupture happens down line from the meter? All the flow in the world but not getting to the nozzle. Perhaps just a LARGE knock light in the dash so you can get out of it before real damage occurs? I am really curious what you think is prudent in this situation.

Right now Snow says there flow-meter solution is unavailable.

TurboTommy

I've used pressure switches in the past.
The biggest problem I've encountered with them is their inconsistencies when exposed to heat. Even if you set them at a certain activation point, It'll change depending on the ambient temps (depending on where you locate the switch), or underhood temps (hot day, city traffic, etc.)

As far as the clogged nozzzle thing; most of the kits all come with fine filters, and if you keep everthing clean, I don't see why there would ever be a problem.

Toddk911,
yes, you will benefit from a cooler charge; but keep in mind it will only cool down to the condensation point, so it's not like the more water will automatically make your charge denser.

Geneqco

Yeah, only girls have periods over here!

fast951

Initially I identified the possible points of failure. Instead of just looking for failures, I also looked for correct behavior and how they interlaced. A processor with logic was needed. As a simple example of fault detection:

- Status 1: Pump or solenoid activated (activation based on whatever conditions you want)
- Status 2: Pressure in the line before the nozzle

For the system to work properly Status #1 AND #2 must both be TRUE (actually there is a timing variable in there, but let's not worry about it for now).

If Condition #1 is TRUE but #2 FAILS = No water in the line.
If condition #1 is FALSE but #2 is TRUE = Clogged Nozzle

In a fail-safe system there are many conditions to detect, not just 2. The system I designed will automatically revert engine management & boost control to a predetermined state where it's safe to operate without WI.
The system I was designing, incorporated knock for feedback as well.
Under some conditions, even a operational WI cannot save you. ex: Nozzle sized fine for the boost you tune it for, but you run more boost! Your WI is inadequate and you must revert to a fail-safe mode.

As you can tell, it's easy to build a WI system. But to build a fail-safe system it's not as simple and will cost more $ than the generic system most get excited about.

Charlie944

No John, no offense taken whatsoever. You are looking out for us
I have thought about a clogged nozzle and therefore having pressure but no flow or inadequate flow. Right now I only have a 2-bar absolute MAP sensor so anything over 15psi of boost at this point will not happen. I am looking to reduce EGT's and advance some timing, but it will be a gradual process.
The stg 2 kit I have does come with a 20 micron filter that is placed between the tank and the pump.
The injector nozzle itself has a another screen as well.

Thanks again!!

Laust Pedersen

Pinging/detonation is a very good feedback mechanism for problems with a WI or PWI system and I rely on the audible type with ”bio-feedback” (=me). I can assure you, from the few times I have run out of water it is very audible. The temporary cure, until the problem is fixed, is a well-controlled right foot. In a race situation with a helmet on, that does not work though.

I believe that the ”bio-feedback” is fully adequate for those who 1. listens to their car whenever boost exceeds a certain level, 2. do not believe a few pings will kill the engine, 3. have no racetrack events or 4. have racetrack events not requiring WI (lower boost and/or race gas).

So far all is just fine with my engine after 2+ years with a primitively controlled PWI system, 25 psi boost and 87 octane pump gas (91 octane for the occasional track event).



PWI systems actually has a self “cleaning nozzle” feature, since the individual ports have synchronized out of phase pressure oscillations, which whenever the PWI system is not engaged pumps first water then air through the nozzles and lines in between them.

Foreign particles can be filtered out, even better in a re-circulating system similar to the fuel system. However I would be more concerned about dissolved minerals such as calcium (hard water), which often clogs up my external IC spray, but never the internal port spray. I suspect that the slight oil mist in the intake makes deposits in the port nozzles even more difficult.

Laust

gjoey66

Will the Stock DME KLR compensate for the meth injection? just curious if i'd have to upgrade or piggyback

JE_951

I was thinking about what voltage you would set the Snow kit at and stumbled upon this... http://www.snowperformance.net/product.php?pk=8

Its a kit that detects boost rather then MAF voltage. This way I can set it at 14psi for when the 26/6 is really getting hot and not have to worry about it using all of the water/meth when doing around town driving. Then agian I see 15psi on my way to work everyday haha...

JE_951

their stage 1 (also boost controlled) is also only $250.

I am looking to cool my intake temps and possibly run a little leaner while under boost (from 11.8-12.2 now to 12.2 to 12.4 afr). For people who ONLY want to lower intake temps, this kit has everything you need and is very safe (since you will not be changing your afr, timing, etc..)