SD2/Powerlogger Pro general discussion

Well, around here there is no such thing as a straight, or flat piece of roadway, so while cruising along with regular traffic and speeds the area covered in the VE table during such cruising is quite large. RPM ranges from about 1,000 up to 2400, and MAP readings from about 30 up to 80. So that's a pretty significant block of cells.
And I had to analyze almost every cell touched by the bubble in that large block because the same +/- value couldn't be used in all of them. Most of my changes were minus adjustments but varied from -2 to -8 or more.
 
TurboDave said:
Well, around here there is no such thing as a straight, or flat piece of roadway, so while cruising along with regular traffic and speeds the area covered in the VE table during such cruising is quite large. RPM ranges from about 1,000 up to 2400, and MAP readings from about 30 up to 80. So that's a pretty significant block of cells.
And I had to analyze almost every cell touched by the bubble in that large block because the same +/- value couldn't be used in all of them. Most of my changes were minus adjustments but varied from -2 to -8 or more.
Click to expand...

Dave what was your strategy for this? Knowing that each cell is effected by the surrounding cells mathematically by a formula, did you just adjust each cell by a small amount and check it one at a time or did you change it to the number that the air fuel correction was commanding at that given map/rpm?
 
missin' 2 said:
post 534 will give you some info. most of the people I have talked to have been using the GM sensor not sure if they will make it sensor specific or allow a veriety of sensors.
Click to expand...

all the data indicates that the different sensors are essentially equivalent.

Bob
 
missin' 2 said:
Dave what was your strategy for this? Knowing that each cell is effected by the surrounding cells mathematically by a formula, did you just adjust each cell by a small amount and check it one at a time or did you change it to the number that the air fuel correction was commanding at that given map/rpm?
Click to expand...

Well, it was fairly involved. Took a fairly long cruise of about 5 miles or so and logged that. Got back to the house and started going through the log and recording on paper the values I was seeing. I basically wrote several columns of rpm values from 1400 to 2400 and map values from 25 down to 80 which is a pretty big chunk of cells. I went through the log, and watched the bubble, and noted the average value of AfC in each cell and once all those values were on paper it was easy to see the trend. All the values were trending from -2 to -9 so I could see that I just needed to make those values in each cell. I didn't get too fancy trying to "blend" the values because I had a large range of cells and saw the bubble hit the same cells multiple times while in 3rd gear, 4th gear, TCC locked or unlocked, so it all worked out well.

My next project will be to observe the cells traveled through during spool up, and also the cells that are at map values of 100-180.

Don't have to worry too much about the WOT cells, they're doing great as is.
 
Dave are doing this for better fuel milage or a smoother running car?? Or is it your just having fun tweaking things and watching the changes it makes?? I guess I'm curious if there was an end game to what you were doing!!
 
I guess, all of the above. I have found through experience that there is NOTHING that can top the fuel mileage that the narrowband sensor can achieve during normal cruise conditions (not WOT). It was true with the Translator Pro, and now with the SD2. The Narrowband O2 have VERY TIGHT, and VERY FAST control of fueling when in narrowband closed loop and as long as you're in that mode it will maintain a good 14.7-15.0 AFR and do it rock solid, until you push it too hard and open the loop. Since I don't race anylonger, I'm also a real "stickler" for perfect street manners!!!!! And of course, once I get over my 60mph set threashold, then I have lean cruise kick in at 16.0:1.

So I noticed during cruise logs, that the correction was liking to stay in the negative range, usually -7 to -10, so the "tweaker" in me said I can make that better, and it did as can be seen by my latest posted graph display. You can see the AfC is hovering around zero. At least now, if weather or something else changes what the AfC needs to do, there's room above and below zero for it to "roam".
 
How does the narrow band work. Just at idle or is there a threshold that switches it to wb afr?

Posted from the TurboBuick.Com mobile app
 
TurboDave said:
I guess, all of the above. I have found through experience that there is NOTHING that can top the fuel mileage that the narrowband sensor can achieve during normal cruise conditions (not WOT). It was true with the Translator Pro, and now with the SD2. The Narrowband O2 have VERY TIGHT, and VERY FAST control of fueling when in narrowband closed loop and as long as you're in that mode it will maintain a good 14.7-15.0 AFR and do it rock solid, until you push it too hard and open the loop. Since I don't race anylonger, I'm also a real "stickler" for perfect street manners!!!!! And of course, once I get over my 60mph set threashold, then I have lean cruise kick in at 16.0:1.

So I noticed during cruise logs, that the correction was liking to stay in the negative range, usually -7 to -10, so the "tweaker" in me said I can make that better, and it did as can be seen by my latest posted graph display. You can see the AfC is hovering around zero. At least now, if weather or something else changes what the AfC needs to do, there's room above and below zero for it to "roam".
Click to expand...


That's awesome your doing well with this SD stuff!! I hope to be switching over this summer and will be bending your ear....
 
missin' 2 said:
How does the narrow band work. Just at idle or is there a threshold that switches it to wb afr?

Posted from the TurboBuick.Com mobile app
Click to expand...

It is turned on with an option on the Tune Page, and you have to set the Target AFR table cells where you want narrowband tracking to occur to a value of 14.5-14.7
I set mine to 14.5.
No, SD2 doesn't have an option for narrowband tracking at idle, just cruise. But I set my idle cells to 14.3 and the wideband tracks that very well, mostly because there's no throttle movement to force the wideband to try and keep up with tps changes.
I've learned over the years that the wideband just can't track fast enough when there are almost constant throttle changes. It's especially true around here because there is abosolute not a straight or level piece of road here, and that's not an exaguration!!

Here you can see how I've distributed the 14.5's to force narrowband tracking.:

NB tracking.jpg
 
I'm having a bit of a hot start issue- cold start is flawless, but if I shut it off and run in the store and try to restart it's super lean till the 30 second timer is met. It has an embarrassing surge and the wb (after it warms up and starts reading, about 10 seconds) reads around 16:1... should I add startup fuel and if i do, will that affect my cold start setting? Nothing in the instructions mentions hot starting adjustments. Thanks any and all!
 
get a hotstart log, eric and I have discussed this a little, I'm sure we can come up with a fix.

the narrowband should work at idle, there is nothing in the routine that shuts it off at idle. These cars (all of mine anyway) are happier when idling a little richer.

Bob
 
Cool, thanks bob- it'll be a week or so, fuel pump took a Crap the other day and I won't have a chance to change it out for a bit. Feast or famine with side work!
 
I am a little off subject , but I wanted to know if anyone has had a difference in your boost gauge an the boost setting in the PL. It has me confused now I think my gauge is bad.
 
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