In the 6E .bin, the spark advance table only goes up to 4800rpm and 208 LV8 (load value). From the perspective of more experienced tuners, can I go into my definition file and make the table larger or change the bounds to be longer? I've noticed that I get some knock but only above 225-230 LV8 and down below 3800rpm, so if I can pull timing there and add it back in later, I might be able to extend the torque band and push the power peak a bit higher. Even with the Comp 8-502-8 (XR269HR grind pattern) camshaft, which is supposed to keep the power peak up around 5000-5200rpm and then pretty much level off to 5500, I find that after 4500rpm or so it feels like it stops accelerating nearly as hard. I also have a double hump head from a 69 Z28 and I'm running around 10:1 compression, which typically will like 34-36* of spark advance, but I can only seem to get 28-30 degrees without running into knock issues. If I can extend the tables, then I might be able to put more timing in it up top and make that power where I should be.

 

You need to change the ECM firmware (code) in order to extend/change tables. But yes, that can be done. Then once finished the XDF file will need to be added-to/changed to match the new tables.

But it is the ECM code that defines the table layouts, not the XDF.

RBob.

 

what intake is on this?

 

This is a TPI system. After doing a datalog with 28* total timing in by 3200rpm, I'm still seeing knock amd wondering if it could be false or possibly due to my PCV valve pulling in oil from the valve cover.

 

You may already know this and not saying this is exactly your case but with stock length runners, it's mostly going to fall flat at that rpm anyway. I had a 8-501-8 cam under a stock tpi and the power didn't hold flat after 4500, just started dropping off.

 

Here's what I am thinking.

You could try lowering the LV8 by artificially lowering the MAF table (air flow) and reducing injector rate to keep the same INJ PW. That way, your BLM, OL and PE would not be affected. Cranking would not be affected either.

LV8 = (((983040/RPM*Air Flow)/256)*80)/64

Example:
208/230 = 0.904
So you would need to lower MAF table by 11% and increase Injector rate by 11%
Let's say injector rate 19.48 with MAF 9.28g/sec, 1950rpm, AFR 14.73 = ((((9.28/8)/(1950/60))*2)/14.73)/((19.48/60/60)*1000/2.20462)*1000/2 = 0.99msec
LV8 = (((983040/1950*9.28)/256)*80)/64 = 23
Reduce injector rate to 17.33 (-11%) and decrease MAF to 8.26g/sec (-11%), everything else equal = ((((8.26/8)/(1950/60))*2)/14.73)/((17.33/60/60)*1000/2.20462)*1000/2 = 0.99msec
LV8 = (((983040/1950*8.26)/256)*80)/64 = 20

Would have to be tested to make sure it does not affect drivability at low rpm/air flow. You would need to reprogram your SA tables and everything else that relies on LV8. I actually use this trick sometimes to lower MAF and LV8 at WOT to avoid maxing out at 255. Only difference is, I don't touch the injector rate, instead I adjust PE AFR.

I find it's one of the main problems with using $6E on performance engine. The "255 max out" can come quickly. Also the entire SA table gets pushed out of range. One needs to retune the SA tables and can not rely on any OEM tune.

Hope this helps.