I just completed a year of tuning my 396SB with cam236/2442 @.05 112 LSA. Seems I was chasing my tail initially. With convectional driving it continually added fuel per dalaogs. It was taking out the fuel I was adding in tables per logs.. I did a vac test at idle and saw 11 in. HG. It appears the overlap allows reversion and that is reason for lean at NB. My WB reports to ECU 14.9-15.5 often.in cruising low load
If there was a RPM based value for triggering CL would that be of help.?

I idled OL second first half of year and just today moved CL temp to 116C so as to run OL all the time starting this spring..

Thank you for comments.

 

I've run an open loop tune for about a year and a half. A manual transmission is a real pain in traffic if it is not smooth at lower rpm's. My combination wants 13-13.5 AFR at idle and gradually increase to about 14.7 after 1400 rpms. It runs great that way. I would like to have closed loop after 1400 rpms but I don't believe there is any way to do that. I've done WB VE learns and many data logs. The AFR seems to stay consistently where I want it. Hiway mode puts me about 15.5 - 16 AFR. It runs so good in open loop I don't feel the need to change anything.

 

Can offer a second set of eyes if you think it would help, just to go over the bin...

- Rob

 

I turned the NB off. I am using WB reporting data A/F to logs but not using WB in place of NB. Problem is over cept if weather gets real warm. Did logs at 50d F. I have reached a point where readings no longer lean and stable at stoich for most points. Car is a monster. I need drag radials..
Prior issue was lack of fuel( 255L) pump. I upped the FP to53. 36 lb inj's. Seems OK now. Thank you !