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8 Cylinder Direct Injection + Secondary Port Injection Possible?

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Hi guys

Noobie question here, sorry about this but I am baffled about a few things. I am running a Lexus with 1UR-FSE with D-4S. Am I able to setup the Xtreme just to control the port injection while the factory ECU is retained to control the direct injection? So in other words, the Xtreme is used as a piggy back. Referencing this thread Here, I know it is possible but I am not sure how this works now with direct injection present. Just to put this in context, my plans include a custom plenum to accommodate a M122 supercharger. Higher boost requires more fueling which I am hoping to achieve with a custom fuel rail and larger injectors.

Thank you very much.

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I know of some people that have done this but it’s not a good option in my opinion.  Having two separate ecu’s controlling things with no communication between them and little understanding of how the oem ecu controls things is bringing a lot of risk to the party.    For instance if the oem ecu cuts fuel as a limiter but your port injectors are still squirting you are probably going to melt parts quickly.  With port/DI combos there are many other scenarios where the timing difference between the two injection events can cause very lean cycles also.

Fair enough if it’s a junk yard engine with not much value and you are prepared to learn by breaking things...  

 

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32 minutes ago, Adamw said:

I know of some people that have done this but it’s not a good option in my opinion.  Having two separate ecu’s controlling things with no communication between them and little understanding of how the oem ecu controls things is bringing a lot of risk to the party.    For instance if the oem ecu cuts fuel as a limiter but your port injectors are still squirting you are probably going to melt parts quickly.  With port/DI combos there are many other scenarios where the timing difference between the two injection events can cause very lean cycles also.

Fair enough if it’s a junk yard engine with not much value and you are prepared to learn by breaking things...  

 

Thanks for your input AdamW. Is it then possible/recommended to remove the DI and just have port injection take care of the fueling. I know this is taking a step backwards but at least i do not need to deal with the complications of DI...

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