I had my car dyno tuned and know that my air fuel is mid 11's from 3000 rpm up but I wasn't happy with my spark advance, I knew my car had alot more power than what it was tuned for (the tuner had little or no experience tuning a LS-1 with a Magnuson s/c).

The first thing I did was started to add timing and then I added more, I pretty much doubled alot of the cells and from 4000 rpm up thru 6500 rpm I went from 12 degrees to 19 degrees, this really woke the car up and now it's running like it should have been when I left the tuners shop, I still don't have any detonation and I may try to go from 19 to 20 or 21 degrees.

Now I'm ready to adjust fuel, I know the car is running excessively rich because my exhaust tips turn black within a few miles after I clean them and they weren't like that with my last tune from a different shop (where the car actually ran great after being tuned).

I hear alot of different terms, what is the definition of +ve and -ve?

I know LTFT and STFT are long term fuel trim and short term fuel trim but what do they actually mean and how do you adjust them?

Also, I hear of people resetting there fuel trims by pulling fuses, what does this do?

I have 42# ford svo injectors on my car how do I set the IFR table or know what to set it at if I change injectors?

Thanks in advance