This interesting (just learning HPTuners and want to
mess spark around). So the spark retard limit is the
"drop-to" limit and not a "drop-by" limit? Is that the
way you guys have it mapped out?

 

Hey Black Blown, did the timing advice help out? I read you can still only get 16 degress. What is your a/f ratio at?

 

It's a drop to limit.

 

Heres the latest. Got it up to 20 degrees in 1st gear, 19 down to 17 in second, and 17 to 15 in 3rd. Did this with IAT vs MAP like you said. First and second gear seen a little stronger now for sure.

Interesting thing though, it can't handle 20 degrees in second or third gear, and can only handle 16 in third gear. It seems load has more of a bearing on the timing it can take than IAT. Example...if I'm cruising at 70mph with near ambient IAT's and punch it, It gets 20 degrees of timing until IAT reaches a certain point. It can't handle 20 degrees in Third gear. So the only time the 20-15 table works is when I'm racing from a stop.

Right now, I have my 15 degres flat across tune in. When I go to the track or to the street races, I'll load the 20-15 table.

My A/F is 12-1 flat. I think the thing thats killing me is the 91 octane premium here.

 

Your 5.3 4wd would certainly be under a greater load than my 6.0 2wd for sure. There are ceratinly differences in my old setup than yours and the octane level might be the biggest. Well, I do hope that you can tell a noticeable difference.

 

When my track opens I'll run it with the 15 flat tune and the 20-15 tune back to back and report my findings. I wish I could buy 93 octane here!

 

I think maybe this relates to the speed of the run-up in RPM?
Things like the airflow and the spark advance that depend on
"load" or MAF value will always "be a little behind" when you
are spinning up fast in 1st, while 3rd gear is closer to steady-
state and the "real" advance the engine can tolerate under
continuous operation at fixed RPM.

 

Call John Rovner if you've not got this worked out. He's very good.

 

I got a new intercooler, and now I'm able to run 18 degrees in all gears. It will definately take more timing in first and second than third still. I think it has to do with the speed that the rpm runs up. Part of my problem was the dinky ATI intercooler for sure. Thanks.