Setting up B8020 and B8021

[Chalky]

Can someone help me understand how you set the Zone and RPM boundaries in the E38? I am looking at the factory VVE table and it is not a smooth table. When the table crosses over from one MAP boundary to the next, it looks like a vertical wall.

I believe I can establish the MAP boundaries but the rpm boundary is the one I cannot get my head around. In my case, my car idles @ 650, I cruise at 1600 rpm normally, I shift when cruising around 3000 and engine redlines at 7000 rpm.

Factory boundaries for rpm boundaries are 1000, 1750, 2500, 3500.

[Chalky]

No one?

[etmotorsports]

That should be good post up a tune

[GMPX]

Have you read Simon's (Swingtan) tutorial on setting up the VVE?

Virtual VE Adjustment Tutorial (http://download.efilive.com/Tutorials/PDF/Virtual VE Adjustment Tutorial.pdf)

Virtual VE Tutorial (http://download.efilive.com/Tutorials/PDF/Virtual VE Tutorial.pdf)

[Chalky]

Yes I have. I did find a thread where the discussion touched on rpm boundaries. Just trying to get a better understanding of the whys.

Take a look at the GM LS7 VVE table. This is contrary to everything I have observed and read regarding the VVE! It seems that the rpm boundaries are a critical part of the process but GM delivers a car with vertical walls in their VVE.

[swingtan]

If the car is stock, I'd stick with 1000, 2200, 3400, 4600 for the RPM boundaries and the stock MAP boundaries will work fine.

[GMPX]

ok, by wall do you mean like the transition from Zone 27 to 28 at 7,000RPM, 60kPa? If yes, then it's a non issue.

[Chalky]

That would be it. That area looks like it would be an area of the VVE to see little use. I was quite comfortable with the LS1/LS6 ecm and VE tables. I am just trying to get a better feel for how the E38 VVE table works..

[Chalky]

If the car is stock, I'd stick with 1000, 2200, 3400, 4600 for the RPM boundaries and the stock MAP boundaries will work fine.

Thanks for the reply. Based on a thread I believe you responded to, I can understand your choices of 1000,2200,3400. Just wondering how you determined using 4600 for the last entry in the rpm boundary?

[swingtan]

I just continued the same increase as for the previous points. It does however allow for a nice curve over the peak power points of the RPM .

RE: the LS7 tune, all stock tunes ignore the VVE completely after the "high speed air flow, RPM limit" is met, normally 4000RPM. So it doesn;t really matter what is in the VVE above 4K RPM. It also explains the stock RPM zone boundaries.

Simon

[Chalky]

Thanks Swing. Appreciate the input.

[The Alchemist]

11936
when I do a mafless tune in any E38 controlled engine I change the rpm breaks to 1500 2500 3500 4500. This tends to allow the curves to follow the natural airflow characteristics of the engine. Curves can flow either convex or concave over 1 transition. 4500 being peak torque rpm of course.
I have seen the "wall" in some LS3 calibrations. Not present in L98 tunes that I have found...

If you fit a cam these points change again to suit the new airflow.

[swingtan]

That's exactly right Mike. The zone boundaries need to be set up to suit the motor. There is no "one setting fits all", each engine will need to be looked at for the modifications it has. However, motors with similar modifications will have similar settings.