afr spark ?

**Jdiding** · 01-14-2017

been working on the tune in my car
from what scotty has told me the actual timing is always 5* higher than what the good fuel spark table says. my car seems to be 8* over that from watching commanded spark
i see in the afr spark setting that it adds 7.99* of timing if its 9.7 commanded afr is that where the 8* extra im seeing is coming from ?

can i set that to 5* so make setting my timing simple ? so it will be 5* across the board

**Fivefingerdeathpunch** · 01-14-2017

Yes, that is where it comes from. It vaires from like 3º to 8º depending on commanded AFR. I'd have to screen shot it with HPT to show it though.

You can remove the AFR spark adder and set the commanding timing to whatever number you really want to.

It's what did with HP Tuners.

**Jdiding** · 01-14-2017

im just gonna take the 7.99* at 9.7 to 5* so it quits screwing me up..
what table sets the wot commanded fueling

**Fivefingerdeathpunch** · 01-14-2017

In HP Tuners it's Base AFR vs ECT and then it adds fuel with a table called ADD vs RPM.

So it's 12.40 + the add vs rpm table that brings in more fuel depending on rpm and how long you are in PE (power enrichment). Most just zero out the add vs rpm table and make the commanded AFR a straight 11.5 or whatever they choose.

I don't have DHP so I forget what they might call them exactly.