Supercharged111
Truly Awesome
- Joined
- Aug 20, 2015
- Messages
- 13,427
- Reaction score
- 17,233
Well I'm on the 8th or 9th tune and it is still pinging hard at 1800 when towing and moderate 30-40% throttle. I emailed BB a log of the current tune along with a log from the previous tune and I see no difference. Both show 6-7 deg KR at 1800 rpm and 20-40% throttle. Tuner replied and said we need to go back to the very first spark table, which gave only 5-7 deg additional cruise timing over the WOT curve. So I just sent the following email. I will send the box back up again, but I just don't understand why the cruise timing can't drop off more aggressively toward the WOT curve as throttle and map goes up and vac goes down.
"Ok I will send it back, so do whatever it takes.
I was definitely wrong about the wot timing curve and I apologize for that. For part throttle conditions I requested more timing at real light throttle cruise; say 1800-2k and 60-65 mph on flat ground with no load and high mani vacuum. (forgive me for still thinking it terms of vacuum). And it did in fact get better milage at that condition when timing there was 30+ rather than low 20's. I know now that this engine needs only about 16 deg at 1800-2k and WOT. I just wonder why can't the cruise timing drop off more aggressively as throttle goes up? At only 1800 rpm, 30% throttle will result in pretty low mani pressure, so the timing should drop pretty close to the wot number. Is it not possible or not easy to have the timing drop by 15 deg or more when it goes from max vac to minimum? I have seen those 3d spark tables and I would not want to try to set each of those numbers by hand."
Maybe he doesn't want to either? That really is the secret sauce that makes these so much nicer to drive. Sure more WOT timing can wake them up, but using less throttle to loaf along is something you can enjoy on a drive anywhere.