Phil99vette

iTrader: (11)

I have been working on the tune for the last couple of weeks and have been getting fustrated. My old tune from LS1edit worked fine but the LTFT's were out of wack. The car ran strong, 10.0 @ 138 on a soft pass. Now I am tuning with HP's SD tune and the car just acts crazy. Here's what I did and noticed

1) Did a full speed density tune + - 3 @ 13.0
- The car runs good in SD mode but burns alot of gas and has some slight knock

2) Calibrated the MAF(with and without the screen, stock ends/ported ends)
- The calibrated MAF did not look correct, it had the same general curve as the stocker but it was very rough in some parts. I figured the curve would be linear but as it goes up, sometimes it jumps up slightly and dips quickly and than back on the normal curve. Any ideas?

3) Before the car ran pretty good aside from the fuel trims, now when I go from SD mode to normal mode the car wants to...
- drive normal and sputter on occassion
- At idle loud pops almost like too much fuel
- Does the car just need to be driven and "learn"?
- The LTFT's are way different from SD mode with and without screen -12 in some areas

4) What should the VE table look like?
- HP Graph
- TQ Graph

5) Does the car use the MAF with a reference to the VE table for fueling?
- Would it make sense to tune the VE table with MAF(fuel trims turned off) so you can see what the computer is commanding between the 2 tables?

Here's some things I have noted from before to after:
1) IFR table
- before I simply multiplied by 168% across the board
- now I calculate it using a spread sheet
** my impression is it runs better before

2) VE table
- before I leaned the ve table out on the low end to get it to idle
- now I tuned the VE table to 6500
** The car still has the same out of wack trims as before but doesn't run as good all around as before

Can someone please point me in the right direction? I have missed 3 weeks of racing trying to get this POS car "tuned" correctly. HELP ME!
Phil