VEAL Lambda Delay

[Rick Finsta]

~500HP Domestic V8 running 30" primary (1.75" diameter) headers into merge collectors (figure 14" long, venturi is 2.5" back up to 3" exhaust) and then a few more inches to the O2 sensor (I have a bung in either side but only run one sensor), then into the X-Pipe (it's 3" from the merge venturi to the exhaust exit). So I think 50-52" is about right from the valve to the O2 sensor. Does this table look ridiculous? It's what I got from my datalogs but seemed excessive based on the standard table. Car idles at 900rpm warm and redline is 6800. I don't have the VE completely retuned since swapping over to Incorporate AFR Target so I've only had it up around redline once or twice.

100 400 200 50
60. 600 400 200
30. 1400 1200 600
.... 1200 2250 6500

Wanna make sure I'm not way off base. Thanks!

[kaeman]

I am with you, I know I found some info on how to calculate the time for the table, but I haven't been able to find it, now that I have changed my sensor location futher back in the exhaust pipe.
when using megalog viewer how do you calculate what the setting for the ego delay should be, when you are using the analyzer.

[Rick Finsta]

What I did was watch for a large difference in commanded pulsewidth, and then noted the time, then moved the cursor forward to where the AFR starts to react in that direction, and noted the time. What is difficult is finding areas in the log close enough to all the same RPM but under different load conditions.

Honestly, VEAL works great with the stock settings but I figured it wouldn't hurt to dial it in better.

[Paul_VR6]

I usually enable a fuel cut rev limiter at a few rpms and hit it at different maps and log it all to get the time between pw=0 and the afr response.

[kaeman]

Thanks Paul,
That sounds like a pretty easy way to get some quick info to set the table. I am assuming your using the sd card to datalog this info. Should we be doing anything to the ego settings page, like change from ignition events to use delay table or what, I just don't know if the read time is just 50ms and it doesn't matter about the corrections when doing this test, because all we will be looking for is when the fuel is turned off and when the o2 sensor sees the change.

[Paul_VR6]

I usually use the laptop so I can change the rev limit on the fly. You can do it with sd but it would take a few "laps" changing the limit after each one. Didnt need to do anything in the ego menu at all.

[kaeman]

thanks, I was going to use the sd card to datalog and then use the laptop to change the fuel cut. the sd card records data faster than the laptop as I recall from reading. The laptop collects more data but it updates at a slower rate from what I remember.