Lets talk Aux fueling.. Shotgun or PI?
- Thread starter Clean WHP
- Start date
You gonna need this if you dont have it already for DIY https://www.newtis.info/tisv2/a/en/e90-335i-lim/repair-manuals/11-engine/11-66-vacuum-pump/4Qp0wYq
Thanks... I did see that but hasn't made it to my to-do list yet to track it down.
Instead of this, i wish we spent more time on getting the ecu to work directly with a mac valve. Removing the need for outside hardware. That's a conversation for another thread I guess. I did hear that we can control a second low pressure pump with the stock ecu. Hopefully that'll drop soon. Its been a long time since a public XDF update and if any help or testing is needed, Im always down. If we could get pi under full dme control and get the injector to point at the valve seat we'd be in better shape
@V8bait was able to fully test my code changes this morning and the results are in.
The ignition coil is now disabled when ANY event causes it's corresponding injector to be shut off. This should alleviate the last remaining PI concerns
Since I know it will be asked...no ETA. Code is only written for I8A0S currently, so three rom versions to go, then MHD integration, etc.
The ignition coil is now disabled when ANY event causes it's corresponding injector to be shut off. This should alleviate the last remaining PI concerns
Since I know it will be asked...no ETA. Code is only written for I8A0S currently, so three rom versions to go, then MHD integration, etc.
The problem is there wouldn't be that much of a benefit to justify that project's expense I don't think. If the PI was being used at low rpm and cruise, yes. But not the way we use it.
@V8bait was able to fully test my code changes this morning and the results are in.
The ignition coil is now disabled when ANY event causes it's corresponding injector to be shut off. This should alleviate the last remaining PI concerns
Since I know it will be asked...no ETA. Code is only written for I8A0S currently, so three rom versions to go, then MHD integration, etc.
Quick clarification, so this development will shut off the ignition coil now, but it’s possible that PI will still be pushing fuel into the cylinder?
Correct. But that doesn't really matter much tbh. You'll get a fireball out of your exhaust, and anyone making enough power to need PI should not be running cats anymore either. It's the same as PI only cars with an ignition cut rev limiter, or ignition cut anti-lag, etc.
Thanks Jake, just wanted to get some clarification. Quick follow-up, would there be any threat of hydro lock due to unburnt fuel entering the cylinders?
That fuel is entering the cylinder and will be compressed even in normal operation, the only risk is unburnt fuel not LEAVING the cylinder after multiple strokes. This just isn't going to be a problem, any amount of fuel which could possibly attribute toward a hydrolock would be expelled on the next exhaust stroke. A precise amount of fuel is injected for each stroke cycle. In actual hydrolocking cases, water submersion for example causes unmetered volumes of water or fluid to be drawn in during the intake stroke like a syringe. Another case could be a pooled volume of fluid entering the cylinder from faulty fuel injection system for instance.
This is just my theory, remember I'm a computer guy not cars. But unless you were injecting massive amounts of fuel, I can't see how the exhaust stroke wouldn't take care of this handily.
What is massive? You could start with this:
I foresee more 2 step videos after this mhd update lol....
Once I heard about p.i issues I was gonna go double shotgun. Now that I know there will be a better safety net with p.i. Guess I got plenty of time to decide which to run before I switch to ST.
Once I heard about p.i issues I was gonna go double shotgun. Now that I know there will be a better safety net with p.i. Guess I got plenty of time to decide which to run before I switch to ST.
I think you're going to certainly see more PI now(not much more since it is already the majority). Its cheap and now the main problem I had with it is supposedly going to be eliminated.
Double barrel is still the better choice, all fuel metering is controlled by the dme with full safety.
The problem is all that fuel getting dumped into the exhaust, can cause massive backfires, damaging o2 sensors and if your running cats it will melt them as stated earlier.
MHD is taking a step in the right direction but I got to say Tony has the right idea, double barrel and a hint of pi to supplement the top end and that is the safest way currently so if the cylinder shuts down the amount of fuel entering the cylinder will be insignificant to cause any issues.
The problem is all that fuel getting dumped into the exhaust, can cause massive backfires, damaging o2 sensors and if your running cats it will melt them as stated earlier.
MHD is taking a step in the right direction but I got to say Tony has the right idea, double barrel and a hint of pi to supplement the top end and that is the safest way currently so if the cylinder shuts down the amount of fuel entering the cylinder will be insignificant to cause any issues.
I've also had people tell me that the AIC controller is not ideal in part throttle situations, spraying fuel when you're merely holding a gear and feathering in and out of boost. I've never ran PI on this car so I can't say first hand. But I still think there is a need for a DME controlled PI controller. Needs to have per bank fuel trims taken into account or something even better than that.
Not sure why this would be an issue. You want it to spray X amount of fuel at Ypsi regardless of what you are doing with the throttle, otherwise WOT would be fine and part throttle would be lean.
Single bank
Not sure why this would be an issue. You want it to spray X amount of fuel at Ypsi regardless of what you are doing with the throttle, otherwise WOT would be fine and part throttle would be lean.
Single bank
That solves one problem, but ideally we'd have a 6 bank system
Individual cylinder O2 sensor mod anyone? LOL. Maybe we can stick to EGT
