I am still in the building stage of a twin turbo Fastback. My question is, is it OK to take timing out as the RPM's increase (at say 2,3,4,5k) or is it better to use a 2 BAR map? I have talked with a couple of tech guys and one says one thing and the other says something different. I'm not sure they know all they supposed to know and I certainally don't know what I need to know. The ECM is tunable (speed denisity) and will work with a 2 bar (looking for 8-10lbs) but I will have to go in and change some tables. I stay confused.

 

A map sensor is only used to read the amount of boost. 1 Bar, 2 Bar, 3 Bat, etc.... they all function the same, but will read to different boost levels. The timing will need to be taken out regardless of which map sensor is used.

Chris

 

Does the map normally tell the ecm to remove timing when it senses pressure or does it just control the fueling? I can see the one bar working by determining the amount of boost generated at a given RPM, and taking out timing with the program. Just trying to figure it out. ON EDIT: Another way I was told to handle the fueling when using a one bar is to use a boost reference regulator, as the boost goes up and the fuel pressure raises , the injectors flow rate will increase. Say a 39lb under boost it will act like a 44 or a 45.

 

The map is just a sensor like the coolant temp sensor or the air intake temp sensor. What effect that particular sensor has on the timing or fueling or if it has any effect at all is all dependant on the the ECM and how its programmed. Your best bet is to find what brand of injection system you are using and spend some time reading the instructions and/or user manual from front to back to get familiar with how it operates. On the fuel pressure regulator, any time you are boosting an engine you will have to have a boost referenced regulator. Most factory regulators are boost referenced but not all aftermarket ones are.

Chris

 

Its an Edelbrock Pro Flow 2. I have called two of their tech guys and had a different response from each, and now I'm confused as to which way to go. I think either would work but would like th choose the better of the two. Maybe I'm overcomplicating the issue, but a ounce of prevention is better that a pound of cure. I will try to load the sopfware and nose around this evening. On the regulator, do I need a 1 to 1 or a 2 to 1? Thanks

 

I haven't personally seen anyone use that system with a power adder, but as long as the fuel and timing maps are completely customizable and it will support big enough injectors for the power you want to make then it should work. Boost reference regulators are 1:1.

Chris