tequilaboy

Is rather easily accomplished.

The ecm uses a couple of different internal rpm signals. NTRPM and NTRPMX.

The resolution of NTRPM (typically L0056 in $32 and $32B or L0058 in $6E) is variable, rpm/12.5 below 2400 rpm and rpm/25 above. NTRPMX (typically L0057 in $32 and $32B or L0059 in $6E) has a fixed resolution of rpm/25.

By inputting NTRPMX instead of NTRPM to the main spark 3d lookup table, you can tune with the standard table in 400 rpm increments all the way up to 6400 rpm. Of course you need to label the table rows in your editor accordingly.

You lose the ability to tune in 200 rpm increments below 2400 rpm, but I think this is a reasonable trade-off for those wishing high rpm spark control.

bl85c

iTrader: (2)

Neat, that's a big help for me. Is there a way to change the filtering of the signal? Mine's pretty sketchy because of the way I have the 'reluctor' cut on my dis setup.

bl85c

iTrader: (2)

Another question, what's limiting it to 6400 rpm? When you relabel the table it extends to 6800 rpm. I'm guessing it's the 8 bit calc limit of 6375 rpm.

tequilaboy

My table goes from 0 to 6400 in 400 rpm increments. Just like the other tables that make use of this signal (PE vs rpm, bpw vs rpm vs lv8, etc.)

bl85c

iTrader: (2)

So the constant at L002E isn't used then? I was wondering why I had more spark than I thought I should.

tequilaboy

Good Catch.

You may want to set this value to zero instead of 32 (originally 400 rpm, but now effectively 800 rpm with the extended NTRPMX signal). I idle at 800 rpm, so I didn't bother to check the effects below 800 rpm.

Mines still at 32. Unfortunately, my car is down at the moment so I won't be able to test this for a week or so.

With these settings I have good correlation with the main spark table tested up to 6200 rpm.

Corrections: The 32 value referenced above at LC02E is the actually the min LV8 for the table input, not the min rpm! It is incorrectly labelled in the common arap source hac.

The min rpm is already zero by default. Therefore, there is no reason to change either the min rpm or min LV8 value.

camaro350tpi

hi guys , how can i get the extended ntprm ?? i have tunerpro alson the 165 ecm...

bl85c

iTrader: (2)

Add a new constant at L0E97 and change 58 to 59 (hex digits) then relabel the main table from 0rpm to 6400rpm. You need to reformat the spark map as well.