Learn the Basics - TT Chip and AFR tuning

[gnonyx]

I saw this on the other Buick forum and it's very interesting, and maybe some might want to view
 https://www.youtube.com/watch?v=rZDyisPxD7E&t=3499s

[Steve Wood]

  Note that blm's have nothing to do with wide open throttle fueling. He is not talking about blms in the video.

Now, Eric uses 128 to be the center point of his programmed fueling range..but it is not blms.  Blms are only used for idle and cruise or light throttle.  Once Performance enrichment fueling is invoked, then the ecm follows a programmed fuel curve installed by the programmers and this is what may be shifted by the chip as per the programmer.

The reason that 128 is used is that it is the middle of the potential 8 bit processor ability to define a range...8 bits equals 0-255.  Note that Eric uses a portion of the potential range as an adjustment as depicted in his instructions.

speaking of factory ecm's of course

One thing that might be misleading in the video is that he mentions getting the tps voltage as high as possible by insuring that  the floor mat or tvs cable does not prevent this from happening.  Tps voltage is not particular critical as long as it is sufficient to allow the chip to be programmed.  Once performance enrichment has been triggered, the tps is not used in fueling calculations.  PE is triggered by lv8 as I recall.  Therefore, the tps voltage might be 2.5v when it ceases to be used.  The lv8 number that triggers PE might be around 110 (lv8 equals computed load variable)  TPS is basically used for idle and light throttle, low load fueling.

The reason to get the floor mat out of the way is to allow the throttle blade to open as close to wide open as possible (same reason to not have the tvs cable so tight that it does not allow the blade to open).  If I recall Bob Bailey's comments from long ago, if the blade is just a few degrees short of wide open, it does not make much difference in air flow.

[Shimy87]

Thats an interesting video. Problem is now it makes me think I need a wideband!

[xracerx13]

I feel the same as it does look easy and cool. I have been researching these the past few days.
I might get one some day....... but I never had any trouble tuning with an EGT and stock o2 sensor.

the AEM Electronics 30-0300 X-Series Wideband UEGO Air/Fuel Sensor Controller Gauge is nice cause you get the gauge with it(the gauge has the controller in it) but if you don't care about the gauge you can just get the regular 30-3010 for $175 that does not come with a gauge(controller is in cable).
Both gauge and gauge-less have the 0-5v signal output that power logger needs.
AEM's gauge model 30-0300 has the fastest update rate of any AFR on the market so you don't miss logging a thing and they both come with a Bosch 4.9 WB sensor. the gauge-less 30-0310 is the second fastest update rate on the market.

[~JM~]

Any thoughts on this model?

https://www.plxdevices.com/ProductDetails.asp?ProductCode=897346002719

[Steve Wood]

used to be considered a good brand, but the reviews seem sketchy to me now

[xracerx13]

https://www.aemelectronics.com/files/info/AEM_X-Series_Wideband_Response_Time_Comparison_Chart.jpg