71 Chevelle, LS1/4l60e, EPS 230/238 113+2, hand ported 799s, ported Fast 90/90, Doug's headers, 3.42 12 bolt
Loaded the new tune. Idled like it always did in the shop while it was warming up, but when I put it into gear it starts surging (enough to die the first try) for a bit then settles down. Does the same thing once I stop at lights. So I need to figure that out and do some other idle tweaks once I learn how.
Driving it feels great, nice and crisp. I just drove to work on city streets, but gave it one quick stab in 2nd and the air fuel dropped to a much more respectable 12.8, lean from the base tune's 11.4-11.2 so I'm on the right track. Just need to watch during a longer pull to make sure it doesn't go any leaner and see how everything else feels.
71 Chevelle, LS1/4l60e, EPS 230/238 113+2, hand ported 799s, ported Fast 90/90, Doug's headers, 3.42 12 bolt
Some of this may help:
Originally Posted by joecar
If you get no knock during WOT, the PE AFR 12.8 is good.
Did some more driving last night to really run through some RPM. AFR is 12.8 in the midrange but creeps to 13.12 near the top so I would prefer to fatten that back up.
To do this would I add or subtract from the MAF table? I think I would subtract. Or does it have to be done by modifying the logged values before pasting/multiplying to do what I'm wanting?
I also kept getting frustrated with the VE table looking like a mountain range so I went back to the log and set it to ignore cells with less than 20 hits (since it was a long log session) and I created a new MAP from that. Now my VE table looks MUCH smoother. I adjusted some of the values manually to make it even cleaner. I still have a valley down low in the green areas I need to bring up but it was late and I was getting tired. I hope this new tune will make the idle quality improve back to where it was before I changed the VE table.
Thanks for looking and any pointers guys! I will try to upload the new version of the tune and a screenshot.
71 Chevelle, LS1/4l60e, EPS 230/238 113+2, hand ported 799s, ported Fast 90/90, Doug's headers, 3.42 12 bolt
Adding to the MAF table means more airmass which means more fuel (to maintain a specific AFR).
Doing the paste multiply is the way to correct the MAF (the SELBEN will converge on 1.00 +/- 0.01)...
then adjust B3618 PE table to the AFR or EQR you want.
Yes, set the cell ignore count higher.
Also drive with smoother application of throttle.
Apply a more restrictive filter.
Thank you for those tips!
I loaded the smoother version of the tune. Much better. This time it fired right up cold and idled, even once I put it into gear it didn't surge. The only time it had issues was if I was at very very light throttle and let off completely very quickly. This would cause it to surge.
Everything else seems very good, LTFTs during in town cruise were cycling between -1% to .8% on driver bank and 0% to 1.2% on the passenger bank (my fuel rail is flipped so inlet side is passenger side). I will adjust the PE table like you said to fatten up things some. It runs very strong with these changes so far.
71 Chevelle, LS1/4l60e, EPS 230/238 113+2, hand ported 799s, ported Fast 90/90, Doug's headers, 3.42 12 bolt
See the throttle cracker/follower links above.
Sounds like you got it running goodgood job.
How are the gear shifts, are they firm and positive...?
I didn't notice them being different than normal so I guess that is a good sign haha.
Partially because on street tires I have been trying to just pull through 2nd gear or third gear. I haven't been on a dead enough road to want to run through second and into third and keep going. Tonight I'm going to put the ET streets on so I can see how it feels when it's not spinning.
Thanks again for the help, you made this fairly easy and straightforward. I will check out the link and toy with that some tomorrow. Once I get it to stop surging and dying under those rare occasions I will be very happy with it. Sometimes on warm start up I have been having an issue with it revving itself up to 2k rpm and holding there for about 20 seconds. Would that be related to the same thing?
71 Chevelle, LS1/4l60e, EPS 230/238 113+2, hand ported 799s, ported Fast 90/90, Doug's headers, 3.42 12 bolt
Posting Permissions
Reply With Quote