Help with VVE

[NotSure]

Or, or... what happens if you edit the file on one PC, then copy it to a different PC to write it to the vehicle?? Since the change is not tied to the file itself, I assume it's somewhere in the Editor that made the change instead?

I believe that it is in the Editor, as when I look at someone's posted file it automatically shows their VVE at whatever scaling I had been using last.

I have this half baked theory that it is a good idea for someone tuning a NA engine to at least look at their VVE on a boosted scaling. Sometimes you can have a smooth VVE up to 100 kpa, but when you look at the boost level areas, it goes wonky. Maybe it does not matter since the engine never sees these areas, but it may be causing some of the individual coefficients to be skewed in an unnatural way to make the table fit. Say for example, more weighting should be going on the MAP or MAP2 coefficient but instead it is getting made up on the Constant or a combination of other coefficients.

Same could be said for the other end of the table, below the default 400 rpm starting point. When I first started messing with VVE, some changes I made would negatively affect startup. When I expanded the table, I saw that while the 400 rpm column was staying consistent, it was severely skewing it down low at 100 rpm. In this case maybe the RPM2 was being changed more than it should, instead of another coefficient or combination of coefficients.

[Lsbrz]

I think I screwed up that offset table again. Im running 58psi base pressure. Thats 400kpa. I copied 408kpa through the whole table.

[blindsquirrel]

8kPa is only 1.1603psi.

If there were a column for 398kPa, would that make you feel better? If so, copy the 388 & 408 columns, paste them into the table somewhere with a column between them. Highlight the 3 columns, interpolate, and the middle column will be your 398kPa data. Personally I would not worry about it unless you have to make it exact without touching the rest of the tune ever again. If it still needs to be tuned a discrepancy like that will go away.

[Lsbrz]

I took the data sheet for the ID1000s and copied the 400kpa offset from that, and pasted it to the whole table.

[Lsbrz]

This is the differences between the 2 from the data sheet. I have the data, might as well use the right ones. Yeah maybe 1% difference. IDK I will see what happens. The vacuum line to the regulator might also be collapsing, so I will have to check that out.

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[blindsquirrel]

How are you going to get around the no-VSS issue with your auto trans ECM?

[Lsbrz]

Im not sure how, but my speedometer works. The brz cluster runs off of CANbus and wiring specialties, the company that makes the swap harness, has a translator so all the functions in the brz still works. I just read that the auto ecm with a manual trans will have weird idle hangs and hangs in between shifts. Assuming DFCO doesnt work properly without VSS. I should just get a Camaro ecm and throttle body so it runs right. According to wiring specialties, the module that translates the CANbus from GM to Subaru also translates the factory brz pedal and they assured me itll work with car or truck ecms

[blindsquirrel]

Does the interface box thing only feed the cluster, or is it translating in both directions with a VSS message that the ECM can read? Does your scanner show 158 MPH all the time?

[Lsbrz]

The scanner does always show 158. I dont think its translating both ways other than the pedal input. The cluster, abs, electric power steering all use CANbus. Now that Im thinking about it, that is intriguing how they are getting the speed signal.

[blindsquirrel]

Most likely the stock ABS has a vehicle speed CAN output which is something like an average of all the wheel speeds, unless the box is tied in to a VSS in the trans.

[Lsbrz]

Youre right its the wheel speed sensors because the factory trans didnt have a speed sensor