VS SC $51 Enhanced on T5

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VS SC $51 Enhanced on T5

Postby ralcool » Fri May 22, 2015 12:43 pm

Hey all

I thought I'd post a topic to share some code, some pics, some results.

Long story real short.

The factory code for the VS SC CKUM, even with the transmission flags disabled- is shit to drive as a manual. It pig roots and carries on at light throttle and low rpm.

Probably no surprise to anyone really. I converted over to 'The1's version of my memcal for later upgrades.

Some time learning and investigating, with the aid of the memcal tool (unmolested bins to study)

I've discovered the primary reason hiding in the spark tables.

I've found heaps of different things like the IAC tables, and RDSC, and IDLE spark- most of which I've copied over with some level of guess work.

bwls_spark_table_s.jpg (169.92 KiB) Viewed 6653 times

then its related by birth auto version
bwlt_spark_table_s.jpg (170.7 KiB) Viewed 6653 times

And the similarities to CKUM / $51_VS_Enhanced - Autos have a lot of timing dialed in down low, torque converter load probably.
ckum_spark_table_2_s.jpg (217.35 KiB) Viewed 6653 times

So, I've gone and transfered the cells up to 1800 rpm, and 250gr/sec like so, and shaved *10 more degrees in the first two impossible columns.
ckum_spark_table_3_s.jpg (208.7 KiB) Viewed 6651 times

And the difference is incredible. I picked these cells after watching/replaying the log trace bubble while driving at low rpm and seeing crazy advanced timing on almost no throttle. Car park and traffic light crawling type stuff.

These is still a long way to go to finish my tune, but I feel a lot closer to the end than at the start.


Edited for pic scaling.
Last edited by ralcool on Fri May 22, 2015 1:08 pm, edited 2 times in total.

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Re: VS SC $51 Enhanced on T5

Postby Holden202T » Fri May 22, 2015 12:52 pm

looks like your on the right track!

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Re: VS SC $51 Enhanced on T5

Postby antus » Fri May 22, 2015 4:50 pm

Thanks for posting such detail with all the screen shots. Well documented. I think I'll FAQ this.
Have you read the FAQ? For lots of information and links to significant threads see here: viewtopic.php?f=7&t=1396

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Re: VS SC $51 Enhanced on T5

Postby Dylan » Fri May 22, 2015 5:30 pm

I've noticed similair things on cars with large cam shafts and manual trans.
Less timing doen low helps with the pig rooting. A richer afr does help but I've found less timing is better.

Good work though always good to have a win.

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Re: VS SC $51 Enhanced on T5

Postby ralcool » Fri May 22, 2015 9:33 pm

Cheers for the feedback

I'll post up the remainder of the essential changes shortly... after I clean up and re-visit some areas.

It was a bit like playing whack a mole, I'd been throwing a ideas at the wall, making changes to see what sticks.

Until playing back the log files in real time and what I had to see was a light bulb moment. TPS vs CylAIR vs Advance vs RPM
using the monitors screen.

Remembering that we have that bubble trace feature in TP5 proved beyond doubt what the ecu was doing... awesome.

Now though I have a odd new problem with an inexplicable difference with LH & RH LTFT trims...

I have only one old log file from February or so (due to a data loss) showing these trims working correctly, now they don't

Its like the LH LTFT trims don't work properly like the RH LTFT data does (LH will show as only +/- 0.78) RH might show a range eg, -8.00 to - 11.71

Both L & STFT seem okay, changing quickly, but if you read the STFT history, they differ by the LTFT data each load point..

Its like the LH bank isn't updating LTFT .... Do I have to reset the ecu.. did I disable it somehow???

I'll capture some images to show the problem... its driving me nuts.
lhltft.jpg (125.53 KiB) Viewed 6619 times

rhltft.jpg (129.62 KiB) Viewed 6619 times

stft.jpg (210.05 KiB) Viewed 6615 times

Here's the log file if you are interested. (45mins long) VS_V6_SC_$51_Enhanced_v1.0a.adx to play I guess.
(569.74 KiB) Downloaded 370 times

I've changed the O2 sensors fault finding, umm- I'll know is I have evidence that a different surviving log showed it was okay a few months ago.

good_trims.jpg (28.07 KiB) Viewed 6615 times

Random screen grab when looking normal.


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Re: VS SC $51 Enhanced on T5

Postby VL400 » Fri May 22, 2015 11:36 pm

Great info ralcool :thumbup:

The O2 sensor grounding is an issue that stuffs the bank to bank fuel trims - http://forums.justcommodores.com.au/hol ... oblem.html

The sensors dont look lazy in the log, but you could also swap sensors between banks and see if the fault follows.

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Re: VS SC $51 Enhanced on T5

Postby The1 » Sat May 23, 2015 6:10 pm

Good info, will be good to point people here to help.

Ive usually done the same on auto tunes to manual, change the idle and start of the spark maps and throttle follower tables over and it usually runs fine and doesn't have any stalling issues.

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Re: VS SC $51 Enhanced on T5

Postby ralcool » Sun May 24, 2015 5:01 pm

Hey VL400

That seems to do the trick.

I carefully watched the monitor trace while clipping a link wire between d14/16, and finally a2.

solved.jpg (306.49 KiB) Viewed 6530 times

As a result it looks okay at this point, but it will need a drive to know for sure. The trace lines are identical in this shot.. superimposed, in the driveway.

Linking the O2 sensor grounds evened things up immediately, then A2 brought them to zero. No more mv split between spikes.

Tomorrow is booked for a drive by the missus into town. I'll put the laptop under the seat and log until it passes out into hibernation.


Thanks guys.

And yes, I made a permanent link wire soldered and taped. But that is all at this stage, I cleaned up the block grounding points as well before testing.

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