4800 RPM twice in spark - $8D - Third Generation F-Body Message Boards

anesthes · 08-12-2003, 08:25 PM

I searched on this cuz I thought it was explained. Here goes:

Why does TC display 4800RPM in both the main, and extended spark advance tables?

The bin I'm working on, as downloaded from diy-efi, had two seperate entries for 4800. Others (tpi_roc) has said the 4800 on both tables were identical.

heres how mine looks:

main:

RPM 20 30 40 50 60 70 75 80 85 90 95 100
400 20 20 20 20 20 20 17.6 16.2 14.1 12 9.8 9.8
600 20 20 20 20 20 17.9 14.1 12 9.8 9.8 9.8 9.8
800 20 20 25 29.9 28.1 23.9 21.1 17.9 14.1 12 17.9 17.9
1000 23.9 23.9 29.9 35.9 35.2 34.1 30.9 28.1 23.9 15.1 17.9 17.9
1200 26 28.1 35.9 40.1 38 35.2 30.9 27.1 25 20 23.9 23.9
1400 35.2 39 41.8 41.1 38 36.9 33.4 29.9 27.1 23.9 24.3 24.3
1600 38 43.9 43.9 43.9 41.1 38 35.9 33 29.9 26 23.9 23.9
1800 36.9 38 43.9 43.9 41.8 40.1 34.1 34.1 29.9 27.1 23.9 23.9
2000 39 41.8 46.1 46.1 40.1 40.1 38 34.1 30.9 28.8 24.6 24.6
2200 37.6 43.9 46.1 46.1 40.4 38 36.9 33 29.9 28.8 25.7 25.7
2400 38 42.9 46.1 46.1 40.1 38 34.1 29.9 28.1 26 23.2 23.2
2800 38 46.1 46.1 46.1 40.1 36.9 33 29.9 27.1 25 22.1 22.1
3200 38 46.1 46.1 40.1 36.9 30.9 29.9 28.1 25 23.9 20 20
3600 38 46.1 46.1 42.2 36.9 30.9 28.8 27.1 25 22.9 22.9 22.9
4000 40.1 40.1 46.1 46.1 40.1 34.1 28.8 27.1 25 23.9 22.1 22.1
4400 38 46.1 46.1 43.9 40.4 35.2 32 28.1 27.1 25 26 26
4800 38 46.1 46.1 46.1 38 34.1 32 29.9 28.1 28.1 27.8 27.8

Extended:

4800 46.1 46.1 46.1 46.1 38 34.1 32 29.9 28.1 26 23.9 23.9
5200 46.1 46.1 46.1 46.1 38 34.1 32 29.9 28.1 26 23.9 23.9
5600 46.1 46.1 46.1 46.1 38 34.1 32 29.9 28.1 26 23.9 23.9

after 4800 PE is adding 7 degrees, but my MSD is taking out 8-10 because of boost.

Can anyone explain this??

-- Joe

Slow89Iroc-Z · 08-12-2003, 09:22 PM

on stock bins they are identical.....

tpi_roc · 08-14-2003, 06:23 PM

Anybody with an ECM bench seen which value the ecm uses if the tables are staggered at 4800? The main or extended?

JPrevost · 08-14-2003, 06:31 PM

In TC he has it so that in the def (*.tdf) file overlaps for those tables. It's odd that yours doesn't follow that rule. Download his tdf editor and make certain it's accessing the correct locations for that extended table.

tpi_roc · 08-14-2003, 06:33 PM

All .ecu files i've ran into for gmecm edit and winbin have had the rows in both tables

Never thought to fix that though....

RBob · 08-15-2003, 08:31 AM

Quote:

Originally posted by tpi_roc
Anybody with an ECM bench seen which value the ecm uses if the tables are staggered at 4800? The main or extended?

The code uses the first table up to and including 4775 RPM. Once at 4800 RPM the second table is used. (RPM is in divisions of 25 RPM).

RBob.

tpi_roc · 08-15-2003, 10:31 AM

Does the above apply to the split VE tables as well?

The lower VE table is in incriments of 5, while the upper is in 10s how is that handled?

anesthes · 08-15-2003, 10:38 AM

So 4800 in the first table does nothing, since it immediately switches to the second table?

-- Joe

RBob · 08-15-2003, 11:33 AM

Quote:

Originally posted by tpi_roc
Does the above apply to the split VE tables as well?

The lower VE table is in incriments of 5, while the upper is in 10s how is that handled?

Yes.

The MAP term? It is divided by 2 for the 10KPa increments:

LDAB KMAP
LSRB

RBob.

RBob · 08-15-2003, 11:35 AM

Quote:

Originally posted by anesthes
So 4800 in the first table does nothing, since it immediately switches to the second table?

-- Joe

The 4800 RPM row is used whenever the RPM is between 4400 and 4775. The SA value is interpolated between adjacent rows & columns.

RBob.

anesthes · 08-15-2003, 11:49 AM

Great! Thanks.

tpi_roc · 08-15-2003, 11:54 AM

Why do you suppose GM overlapped that value if the true operating RPMs of those two 4800 rows was different?

anesthes · 08-15-2003, 12:08 PM

Maybe it has something to do with where the factory cam falls flat on its face?

-- Joe

tpi_roc · 08-15-2003, 12:09 PM

Then wouldnt' you expect the VE table to have the same flat spot at the same RPM?