Preturbo 335i Strange Results

[M-W-I system]

Half knowing what his system consists of, Is it possible the the ECU is pulling the timing out due to the increase in air temperature?

[rudypoochris]

No, the timing was being pulled from way too much water all at once. I will diagram the system tonight, but basically the check valve kept tank pressure at peak boost but the solenoid would open at 8psi. At this point in time water pressure would be way higher than air pressure and likely the turbos sucked up a lot of unatomized water. As to why that caused timing to be pulled, I don't know, but it did.

The 335i is a map based system. I am not concerned about the miniscule boost leak to be honest. IAT rising does have anything to do with the boost leak. It only rises with meth on, but even with meth off the boost leak is there.

I am trying to turn down the flow with no reported success (sensor shows pretty much the same flow with the port almost completely closed. I am diagnosing this now since I have sensor issues. What do you guys use for flow control valves?

[M-W-I system]

Originally Posted by rudypoochris

No, the timing was being pulled from way too much water all at once. I will diagram the system tonight, but basically the check valve kept tank pressure at peak boost but the solenoid would open at 8psi. At this point in time water pressure would be way higher than air pressure and likely the turbos sucked up a lot of unatomized water. As to why that caused timing to be pulled, I don't know, but it did.

The 335i is a map based system. I am not concerned about the miniscule boost leak to be honest. IAT rising does have anything to do with the boost leak. It only rises with meth on, but even with meth off the boost leak is there.

I am trying to turn down the flow with no reported success (sensor shows pretty much the same flow with the port almost completely closed. I am diagnosing this now since I have sensor issues. What do you guys use for flow control valves?

Im pretty sure its the same flow valve you have. I want you to try something! take the check valve out from the tank, this means the tank will only be under pressure when you turbo is producing positive boost. This will likely help prevent the the sudden spike in flow pressure which could be the reason behind your problems. also make sure your flow sensor is after the solenoid and on the liquid side of the nozzle.

[leman_opc]

Just a thought - from reading the preturbo injection thread on here I understand the effect on the turbo efficiency in simple words should be that more air mass is pumped by the turbo at same boost pressure.

Now you say your system is MAP based and you expected to see a difference in wastegate solenoid PWM. If my understanding above is correct you wouldn't see any difference as your ECU is boost referenced rather than air mass referenced, so it keeps the boost as desired and simply may not recognise that the air mass and engine torque produced is wrong (higher) due to changed turbo map.

Now, if this guess is true you should see leaner mixture with preturbo injection. Do you have a AFR meter to check? This would be an extremely interesting info....

[indio84]

subscribe . interesting test and results.