Done with VE now onto spark

[majacoby]

I'm done with VE tuning.
What values should I put back in now that said "Off for BLM"?
I was using $42-1227747-V5.1.xdf when I did the VE. I have since moved to $42-1227747-V5.9.3.xdf
Does the version of xdf make a difference?

I ran some more logging in hope to move to the next phase of tuning. I would think Spark advance would be next.

Thanks, MarkJ

[EagleMark]

Version number should not matter. As I do work I up the number, it is usually adding, fine tuning and notes.

Turn back on everything that is applicable to your engine.

Weather alone will make BLM change so get get all excited about them changing. This is magic of EFI. But, as you do work on spark you'll be adding power and torque and see theat the VE fueling will need further adjustments.

[majacoby]

As far as tuning spark advance, in a 28 minute run with a good 4000+ rpm sprint, is a knock counter going to 255 twice a bad thing?
I know less is better. The distributor is set for 0 with jump wire pulled with a timing light. Spark Bias main is 9.84 deg. I'm taking it that is like setting a distributor in a non-efi truck.

Where is the best place to read up on spark advance tuning? I come from the days of points & timing lights. Maybe put a curve kit in too.

MarkJ

[dave w]

I like knowing what the timing is at during steady cruise speeds. Baseline 30mph, 40mph, 50mph, 60mph, 70mph (BLM / INT / Kpa). Sort using Excel!

There are a few factors when working with the timing table:
Spark Knock
Vacuum
BLM / INT

Add some advance, see what happens to vacuum...if vacuum improve, and no knock happened, added timing was a good thing...Check / fix the VE table and verify the vacuum and knock don't change.

Usually high Kpa ( 80 ~ 100) cells don't like much added timing. Usually low Kpa (30 ~ 50) like added timing. The mid Kpa cells are a CHALLENGE to figure out.

dave w

[majacoby]

Steady speeds don't have any knock counts. It' the long hard pulls up a hill in the 60-80 Kpa range that generates the knock counts. I'm trying to tune the truck for pulling trailers with 4 tons of trailer and payload. The truck has 4.10 gears and a built 700r4 for towing.
I know if I'm getting knock counts on a pull, I'm not getting the full power out of the engine.
Dave, I will work with your suggestions listed above.
Thanks, MarkJ