Boost sensing hardware and MAF 3bar sensor

[dthrock]

quote:
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Originally posted by JayC
The harness will work without turbolink. All you need to do to use the variable timing stuff is have the harness plugged in, you don't need TL.
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Jay, Ken or someone,

Ive been reading all the threads that talk about this stuff but Im still confused. Maybe someone could answer the basic stuff that Im missing. Cant understand the details if you dont get the basics, so....

1. What does the boost sensing harness and 3 bar sensor do? Does it provide more feedback to the ecm? Where is the information being routed to that the sensor picks up?

2. Using this information you can use a variable timing chip. If its not giving away any trade secrets, where does this information go in the chip and does it use the feedback from the maf sensor to adjust or do you just use the info you get from the sensor to burn a variable timing chip?

Maybe someone could write up a whitepaper on this stuff. Im sure Im not the only (or first) one to ask these questions.

David

 

[JDEstill]

Originally posted by dthrock
quote:
1. What does the boost sensing harness and 3 bar sensor do? Does it provide more feedback to the ecm? Where is the information being routed to that the sensor picks up?

David -

Are you familiar with the scan tool Turbolink?

As you may or may not know, the ecm has no idea what the manifold pressure is. There is a MAP sensor, but it is only used to drive the stock boost gauge, it is not hooked into the ecm in any way. As such, when looking at a scan tool you cannot tell how much boost you are running.

Ken Mosher, who makes Turbolink, developed a harness that connects a MAP sensor to the MAT sensor wiring, so that what the ecm thinks is the inlet air temperature is really a manifold pressure signal. The Turbolink software has the internal conversions necessary to translate the temperature reading the ecm thinks it sees to the proper pressure reading.

Jays chip uses this signal to do some tricky stuff. It adjusts timing with the MAT signal (which is really the manifold pressure with this harness hooked up), so that at low boost there is more timing and at high boost there is less timing. Don't know if he does anything else with it, but he could if he so desired.

Hope that helps.

John