mrnuke

I'm using Tunercat for making cuatom eproms for my '85 corvette.
('870 ecm)

I was wondering if anyone knows what these tables mean :

Fan, Hysteresis, (Coolant Temp.) = 3.0 Deg C.
Highway Mode Spark LV8 Disable Thresh = 100Counts
Highway Spark Cool Temp Disable Thresh = 59.8 Deg C.
AE Enable Min. Delta LV8 Threshold = 20 Counts
Accel Enrich Enable Pos Delta TPS Thresh = 3.9% TPS
A.E. Disable Negative Delta TPS Thresh = 3.9% TPS
Accel Enrich Delta TPS PW Scale Factor = 0 Mult.
Power Enrich Enable Min. LV8 Threshold = 50 Counts
TCC Enable Min TPS Threshold (High Gear) = 0% TPS
TCC Enable Delta TPS Thresh. (Mid Gear) = 99.6% TPS

IMPORTANT :

Overdrive Disable %TPS (In 4th Gear) = 99.6%

Anyone?

Thanks..

Grumpy

Hysteresis is how much change is ignored by the ecm. So 3d temp means the fan would come on at say 97dC and go off at 93dC.

Counts is the ecm's way of measuring air flow. 100 counts is the air flow part of the Load calculation. So it means at over a given load, the Highway spark is disabled.

% TPS is the amount of throttle opening. Since the initial voltage can vary from car to car, they use a percent from that intial value rather then a given voltage.

PE min LV8 threshold of 50 counts is one of the enable values for PE. Another would be min TPS PE enable.

mrnuke

Cool.

Thanks for the info.

Should I bother changing any of those settings?
I just burned myself a chip with changes to the spark advance, maf table, tcc lockup speeds and a few others. Car runs better then ever.. Major difference in my 2nd gear and 3rd geal pulls..

Trying to see what else i can tweak a bit..

Grumpy

Go slow, take ACCURATE notes.
Get used to what does what, and experiment a lil.
As you get to know your way around the tables, switches, and settings, make little changes, and see what happens.

WARNING!.
Once you really get it dialed in for your driving personality, you'll never be happy in another car.

mrnuke

:yourock: :rockon:

funstick

nope.pictue a scale. imagine a balance between to wieghts. hysteresys is the extra weight to push back against change until the hystersis is overcome allowing the scale to tip.


counts are actually on output of the A/D converter going into the MCU. the ad converter changes a voltage or FQ in a bascially another FQ that the MCU recognizes. the A/D take a analog signal and converters it into a digital one. there usually some clock speed things for the MCU tied in there as well.




actually the reason the OEM's went to % vs volate was becuase of wear. by reading the base Throttle position upon ecm power up they negated te often time consuming and sensless adjustment routines that once plauged dealerships.



the only accurate statment in everything you siad.

as for the 870. if you need help working with it toss me and email id be glad to assit. also check this old post

maf and why its such a pita

i detialed and outline how to tune and what to tune in the $3a and $1f masks.

good luck.

Grumpy

And for the average new guy do you suppose he knows what an A/D converter is, or does?.

For the new guy it would just seem to me, to make the terms as simple and understandable as possible.

Opinions, yada, yada.

mrnuke

Hey,I appreciate the input from both of you.

Just looking through the $1F ecm set for my '870 ecm to see what else I can tweak.

:hail:

funstick

explain what an a/d converter is. its that simple.