TwinCharged
01-31-2006, 10:02 AM
How to tune the LSJ or any car for that matter.
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First thing is first. You need to know what a STOCK car's ECU wants to see.
You need to datalog all the sensors of the stock car under different operating conditions. I use an OBDII scanner for my laptop and datalog all of the sensors and ignition timing. I scan it under normal cruising, idle, WOT, Decell, partial throttle accell. You need to pay attention to MAF sensor peaks, MAP sensor peaks, and ignition timing peaks.
Now you want to go fast but your ECU doesn't. What to do what to do? Well for one is to trick the ECU. Put the ECU in it's happy place. Make it think that everything is OK when the truth is you are boosting the hell out of it. YOu need to reproduce it normal operating conditions by emmulating it's normal sensor outputs. Go no higher than the normal MAF sensor fequencey. No more voltage than what the MAP sensor would normally produce. You need to cap or clamp these sensors off. You need to do it to all of the sensors.
Add boost add fuel. Do not attempt to do anyting to your car with out being able to monitor whats going on. YOU NEED A WIDEBAND O2 before you change boost or attempt to tune anything.
Larger injectors. You want to run larger injectors and pull back on the MAF frequency to make it idle and run right. Well in this situataion you can take the MAF out of it's normal operating scope and result in changes of normal engine operation. (more ignition timing). You can get away with this if it is a narrow margin. Tune in the air fuel ratio that you are looking for then compair the MAF readings with your stock reading. Try and compromise with the tune and meet in the middle. I really don't recommend this method and in the end on the LSJ YOU CAN"T ADD ENOUGH FUEL to make up for the the last few 100 RPMs of the map where the ECU pulls boost.
The best way to tune is to be able to manipulate all sensors that the ECU reads. Tune your so that you do not exceed the peak Grams per second reading on the MAF and KPA on the MAP sensor. By doing this your car thinks that everything is normal. Well how do you get more fuel for the boost? You need to add extra injectors. These injectors are going to tie into your current fuel system and need to be driven off a piggyback that has Pulse Width Injection. You can inject the fuel totally seperate of the factory ECU.
You see the ECU has no idea what is going on. You can get away with Murder this way
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First thing is first. You need to know what a STOCK car's ECU wants to see.
You need to datalog all the sensors of the stock car under different operating conditions. I use an OBDII scanner for my laptop and datalog all of the sensors and ignition timing. I scan it under normal cruising, idle, WOT, Decell, partial throttle accell. You need to pay attention to MAF sensor peaks, MAP sensor peaks, and ignition timing peaks.
Now you want to go fast but your ECU doesn't. What to do what to do? Well for one is to trick the ECU. Put the ECU in it's happy place. Make it think that everything is OK when the truth is you are boosting the hell out of it. YOu need to reproduce it normal operating conditions by emmulating it's normal sensor outputs. Go no higher than the normal MAF sensor fequencey. No more voltage than what the MAP sensor would normally produce. You need to cap or clamp these sensors off. You need to do it to all of the sensors.
Add boost add fuel. Do not attempt to do anyting to your car with out being able to monitor whats going on. YOU NEED A WIDEBAND O2 before you change boost or attempt to tune anything.
Larger injectors. You want to run larger injectors and pull back on the MAF frequency to make it idle and run right. Well in this situataion you can take the MAF out of it's normal operating scope and result in changes of normal engine operation. (more ignition timing). You can get away with this if it is a narrow margin. Tune in the air fuel ratio that you are looking for then compair the MAF readings with your stock reading. Try and compromise with the tune and meet in the middle. I really don't recommend this method and in the end on the LSJ YOU CAN"T ADD ENOUGH FUEL to make up for the the last few 100 RPMs of the map where the ECU pulls boost.
The best way to tune is to be able to manipulate all sensors that the ECU reads. Tune your so that you do not exceed the peak Grams per second reading on the MAF and KPA on the MAP sensor. By doing this your car thinks that everything is normal. Well how do you get more fuel for the boost? You need to add extra injectors. These injectors are going to tie into your current fuel system and need to be driven off a piggyback that has Pulse Width Injection. You can inject the fuel totally seperate of the factory ECU.
You see the ECU has no idea what is going on. You can get away with Murder this way
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