Engine shuts off with half tank of fuel left

[Murray_Calavera]

3 minutes ago, joshuaho96 said:

Yeah I think it’s fair to say my goals are a little weird compared to most that modify their car. I still debate semi-frequently whether it’s worth it to try and do water injection to see if I can run lambda 1 deep into boost. 

What turbo and how much boost are you thinking of running when you try this? 

And do you have something like a plex knock monitor so you can accurately see and hear the detonation that is invariably coming your way?

[joshuaho96]

37 minutes ago, Murray_Calavera said:

What turbo and how much boost are you thinking of running when you try this? 

And do you have something like a plex knock monitor so you can accurately see and hear the detonation that is invariably coming your way?

This would be HKS GTIII-SS turbos. They top out at maybe 25 psi in the midrange at best but can’t do more than 20 psi at high rpm due to the turbine sizing. I would presume with port injection though whatever can be achieved with fuel enrichment should be also doable with water.

As far as knock monitoring goes I’m planning on using the Elite 2500 but I haven’t qualified whether the factory sensor and harness has acceptable SNR. It’s entirely possible I just do flex fuel and stop there though as so many people have told me that water injection is too unreliable for what is basically a secondary fuel injection system.

[Murray_Calavera]

19 minutes ago, joshuaho96 said:

This would be HKS GTIII-SS turbos. They top out at maybe 25 psi in the midrange at best but can’t do more than 20 psi at high rpm due to the turbine sizing. I would presume with port injection though whatever can be achieved with fuel enrichment should be also doable with water.

As far as knock monitoring goes I’m planning on using the Elite 2500 but I haven’t qualified whether the factory sensor and harness has acceptable SNR. It’s entirely possible I just do flex fuel and stop there though as so many people have told me that water injection is too unreliable for what is basically a secondary fuel injection system.

Sounds like your heart is set on this so my advice will be a little different from everyone else's advice. If I was in your shoes I would do this - 

1. Grab a plex knock monitor. Good timing, they just released V3. Even if there are zero issues with the factory sensors and wiring, you still can't verify what the ECU is telling you without actually listening to what is going on. The plex knock monitor will come with sensors, wiring and give you the ability to see and hear what is actually happening. I can't see you doing this and not encountering detonation, best to have every chance of saving the motor by stopping before it is too late. 

2. Grab your water injection kit and go nuts! Play around and enjoy the tuning experience, you are going to be tuning this yourself right? 

As soon as you've satisfied your curiosity, remove the entire water injection kit...

3. Install a flex sensor and go E85, once this is in you'll see how much better it is and you won't go back. 

 

I had a similar thing with wanting to try Nismo 740 cc side feed injectors. I knew they were going to be bad, but I really really wanted the experience of seeing what they were like to tune with. Bad? How bad? I had to know! lol

I'm really happy I had the experience of playing with the Nismo injectors. Sometimes its not about doing the most logical thing or financially sensible thing, I say have fun and enjoy the process

[tridentt150v]

16 hours ago, Murray_Calavera said:

I wasn't going mention this because I'm not trying to start internet arguments, but in the spirit of keeping SAU as a source of truth - 

This isn't really what happens, in the scenario of a large change in throttle opening, the change in pressure causes the fuel to be forced onto the fuel film on the port wall causing the fuel film to grow momentarily. This causes the car to momentarily lean out. This is why transient throttle enrichment exists to inject extra fuel so the car doesn't lean out on tip in.

Single or split spray pattern doesn't matter because it's the pressure change that is forcing the fuel onto the port wall/fuel film.

If your curious about it, you can look at Motec M1 training material as that series of ECU allow for fuel film modelling.

yeah, I was generalising....if you do a search there is probably a plethora of detailed documents out there explaining each nanosecond of a combustion cycle.  I probably could have cut and pasted any one of them for crystal clear precision...but was lazy and cbf'd 😂 

[GTSBoy]

15 hours ago, joshuaho96 said:

whether the factory sensor and harness has acceptable SNR.

Given that they famously provide random results, I'd suggest probably not worth that risk. To be fair, their famously bullshit reliability is from working in combo with the stock ECU, but I think it's far more likely that the sensors and loom suck more than the quite sophisticated (for its time) knock discriminatory board in the stock ECU.