I built a water injection system like the turbo buick systems. This morning I did a single test run. I used 60% water 40% model airplane fuel(methanol/lube).
It triggers at 10psi. When it triggered the boost went to 15psi and I felt an extra kick in the ***. Is this normal behavior for a water injection system? Is it safe?
I know WI allows you to run higher boost levels but I didn't think it would cause them.
I have a stock ECU, downpipe, RB catback, Apexi intakes. Normally, I sometimes see 12psi spike which I attribute to the mods.
I haven't had a chance yet to measure temp changes in the intake. I plan on doing that as soon as I get the time.
Should I increase the water percentage? Or turn the system off because I am a dumbass?

 

well the problem is the airplane fuel, i have a lil rc car 1/10 scale and i think wat ur using is hte nitro fuel for the 2 stroke or 4stroke nitrimethane engines, so tha could be the reason why, other than that i see no reason for water to make anything faster? but the fuel is a mixture of lubes adn nitromethane, usualy there is anyhwere from 20- 40 percent nitromethane

 

It is not ok to run those boost levels on the stock ecu, even with water injection. The water injection will have zero effect on boost levels, you either messed something else up while installing the water injection or you had a coincidental failure of part of the turbo control system. The first thing to check would be the wastegate line to make sure it's still connected.

 

I haven't been using WI in the cooler months...I use a MBC to limit boost, and with the cold AIT's + WI, I'd build more boost and hit fuel cut.

for testing purposes, I'd run 100% distilled water...until you shake everything down, then add more model airplane fuel if you want...small amounts until you reach your goal.

 

The WI wont actually make the car any faster unless you tune for it. It may enable you to run more aggresive timing or leaner AFR with more safety.

I was of the understanding that model fuel contains only a small amount of methanol. It is mixed with oil. I get my methanol form a model shop but ensure its 100% rather than a blend.
Caution when using methanol. It has no smell and is very very toxic.

I run a 2 stage kit and i am going to tune it very soon.

usually you would run between 10 % and 20 % water or water mixture (methanol or water methanol acetone)
Scott

 

Although it's quite possible for the nitromethane additives in the scale model engine fuel to add some power if enough of the mixture is injected at full throttle (it'd have to be quite a bit, however), it wouldn't result in overboost like he's seeing. The stock turbo system would still limit the boost pressure no matter what fuel you use.

 

haha, i actually thought about using that stuff in my water injection system. . . i wonder if itd work out well. . . or if itd just burn up seals and such. . . probably shouldnt try to push it, eh?

 

I thought the model airplane fuel would be good because it would boost octane and it has lubricants already mixed in (castor oil?). Obviously, 40% was too much. I didn't have any pure methanol and I couldn't bring myself to use windsheild washer fluid.
I know 30 ML of methanol can kill you if ingested.
So what I'm hearing from most of you is that the boost should be limited no matter what.
I'm going to go do a test run with the system off and see what it does.
I've seen the same system installed on an FD, but I'm starting to think the nozzle may be too large.

 

since when is the stock system a feed back controll set-up?

 

It's not, but typically a downpipe, cat-back, and intakes do not lead to 15 psi of boost on a properly functioning car....

 

I am still getting the boost spike to 15 with the WI system off. The only other thing I've changed recently is to vent the abv and crv to the atmosphere rather than back into the intakes. Could that contribute to boost spike? I've only had the boost gauge installed for 3 weeks so it may have been doing it all along.
I do know that I felt an extra kick when the system came on. I assume that was from the R/C fuel. I'll check the wastegate line and do some more testing..

 

no...and I'm not sure you are gaining anything by venting the CRV

 

i thought you were supposed to keep the CRV hooked up?!?!?!? unless youre in parallel. . .

man, i may have to try the r/c fuel. . . haha

 

Venting the crv and bov to the atmosphere will not effect the boost level at all, in any way.

 

The reason I vented them to the atmosphere was just to have two less hoses to take off. Geesaman said they vented into the intake for noise supression. Simplification was more important than noise supression.

 

Have you block up the places where thay came from on the intake. Also is the intake sealed.( could be getting unfiltered air and causing a spike.

Once upon a time i drilled my air box and it spiked like a bastard.

Scott

 

Hmmmmm. Yes, I've capped them, but since you said that I'm thinking my front turbo intake hose might be loose or off. It's happened before.
Shame it's cold, dark and friggin pouring outside right now, I'd go check.