View Full Version : Tuned a LQ4 and lots of LS1's....any hints on the LL8?

August 20th, 2007, 11:58 PM
I have read every relevant post here in the forum regarding the LL8's and tuning. A friend has asked me to tune his LL8 before he heads out on a road trip to Michigan (from CT) so he gets better fuel economy, throttle response, etc.

I have tuned my LQ4 as well as several LS1's (and also my old LO4 TBI Silverado and LT1 camaro with other software programs back in the day) so I know a decent amount about DFCO, high/low octane tables, LTFT's (Maf or VE tune), and also a few tranny variables like torque reduction and so on.

Obviously any of the above motors do not have the variable cam timing, so that is a totally new thing for me to play with.

I plan on creating a pid file with knock, normal engine variables, spark advance, and fuel trim (plus 02 voltage) so I can see where I stand. Sounds like the factory tune sometimes even has spark knock on the LL8 so I'll be looking out for that.

Does anyone have any specific hints/tables that they have used to increase economy/performance? I saw that a slight increase in timing, adjustment of VE table, and holding the overdrive a bit longer before kicking down has helped most members here, as well as properly enabling DFCO. Anything else?:help2:

August 21st, 2007, 11:20 PM
no one?

August 22nd, 2007, 06:19 AM
I have done a 06 with limited calibration files , 4 or 5 so can't say much on the subject .
ScarabEpic22 has done some of the older Trailblazers .

August 25th, 2007, 03:30 AM
Ive done my 02 P10, with the help of Alvin at PCM4less. My TB is knocking a bit on 87, so Ive been running 91+ for now, but Im off at college now and without my truck and EFILive for the time being.

I would start by adding 2-3deg timing, smooth the spark tables (big help), lowering PE delay, change shift points, remove TM from engine and trans, and play with the speed limiter. That should be good, and use the DFCO settings in an older thread on here from dfe1 (I think thats who posted them).

August 27th, 2007, 05:12 AM
I tried to use the DFCO setttings and I couldn't get it to activate DFCO for the life of me (the 02's would never go to zero when decelerating). I have it working mint on my 1997 LS1 so I do have an idea of what to do.

Otherwise I ended up making all the changes that scarab suggested. The biggest improvements for SOTP was changing shift times, shift pressure, TM, and PE delay. The engine just can't handle too many changes for spark (we actually reduced spark a bit and it improved the final total advance since it wasn't getting 5 deg of knock retard that it was getting at OEM advance). Oh, I think I retarded the cam a few degrees and it felt a lot better there too.