[gregbar]

When do you set the delay?? Before the MAF transfer function, after, during?? Do you look for the most stable RPM?

[decipha]

hego delay has nothing to do with the maf transfer

hego delay is the amount of time it takes for the hego to see a change in afr

longtubes require a longer delay, since the o2s are further from the head usually

i usually set the whole tables to

20s for longtubes
16 for mid lengths
12 for shortys

[cgrey8]

You can actually go with increasingly smaller values as Load increases. The higher the load, the more exhaust that's being pushed into the headers. So the exhaust delay is reduced. I have my lower Load rows still at stock 10 values. But as Load goes up, I've got values as low as 7 on the top rows.

[gregbar]

I tried 20s but may tune did not like it. Back then my MAF was of. As I got the MAF closer the idle started to surge at the 1300 and 1500 rpm. Do I look for the smoothest rpm or what do I look for? Im running MAC long tubes the sensors are in the collectors.

[decipha]

usually can't run closed loop at idle with longtubes because the hego's cool down too much and report junk

i usually set lolod to 30 and am done with it

also i've witnessed a few times where the afr wouldn't even read correct on longtubes at idle, don't know what that's all about and it only happened a handful of times but keep that in mind

[d347643]

sorry to reopen an old thread but can someone elaborate on what lolod means and what you explaining there? Did Decipha mean low load or.....?

[Chucko]

LOLOD is the minimum load value to enter open loop. Stock on GUFB it's set to 0.5. Typical idle loads are 15-20 or so. The setting decipha suggests,30, puts it above idle loads, and well into part throttle cruise.

[d347643]

pardon my ignorance but why did Ford set this value so low?? If typical idle loads are 10-15 then why wouldn't they choose 5 for example? Any relevance to the .5 value??

thanks,

Drew

[Chucko]

Ford clearly wanted closed loop all the way down to 0.

[dustang83]

When datalogging with longtubes, I've had good luck with using the 'HEGO time shift' and 'Wideband time shift' filters in EA to compensate for the O2 sensor distance from the cylinder head. I usually set it to 3 rows.

[decipha]

keep in mind dustang that only works if the wideband can read correctly, i've tuned quite a few cars that just wouldn't report anything at idle

anytime i deal with a long tube car is always force open loop below 30 and use a vac gauge to set idle fuel and spark