SS-AFC making me run lean

[TurbomanProtege]

hey everybody, well I have a SS- AFC in my MSP and I think its making me run lean. well at idle and just regular cruising my wideband reads around 14.7 which of course is optimum, but when I start to get on it the car creates boost at around 3K RPMs and my wideband read that it leans out more like around 16 then after I hit 4K RPMs thats when it drops down to 10.5 but by 4K RPM Im kinda already almost at full boost. Im running the Supermap. so Im wondering why it leans out under boost. Thanks in advance

 

[adirondakkid]

I haven't had success with my install yet, but it sounds to me like you might want to edit your map a bit. Are you data-logging w/ your wideband connected? If so, you'll be able to tell where you are going lean (RPMs, PSI) and from there corelate that to what cells you should alter. To allow your car to put in more fuel you'll want to increase the cell values where you are going lean.

 

[TurbomanProtege]

ok cool, well I never tuned a car before how user friendly is the unit I catch on pretty quick but getting started is it easy, and when tuning is it tuning per 1000 RPMs or 100 RPMs or how is it set up

 

[Metallic36]

http://www.mazdas247.com/forum/showthread.php?t=123620555

 

[TurbomanProtege]

ok well I was reading the FAQs a I see this...Q: How does the AFC know how much boost the car is running?

A: "It has a built in map sensor which tells the afc how much boost you are using and adjusts the fuel map accordingly."

well if this is true what does it do it for me cuz I can be in boost and it doesnt adjust itself

 

[adirondakkid]

ok well I was reading the FAQs a I see this...Q: How does the AFC know how much boost the car is running?

A: "It has a built in map sensor which tells the afc how much boost you are using and adjusts the fuel map accordingly."

well if this is true what does it do it for me cuz I can be in boost and it doesnt adjust itself

the built in MAP sensor is essentially the vacuum line you attach - much like a boost gauge it reads the absolute pressure (AP of MAP...M stands for Manifold I believe). The AFC then takes that pressure/vacuum and uses the values you place into the chart area to adjust fuel trim. The actual values that it is adjusting is the MAF signal that it is receiving from your stock MAF....thus when it goes into open loop as you have it programmed it will begin to use the MAF signal to adjust fuel trim by the amount you have changed the value. 10 is stock, 9.9 is less, 10.1 is more...etc. This is a very basic understanding of how the unit operates, but it is thorough enough for our understanding so that we can adjust the AFR to correct for the overly rich condition set by the factory ECU. When you open the R4 software, you will have the ability to view the maps (Maps - Fuel Map). Map A is what you are interested in.....connect to your car ECU with the key to On, but car not running. open R4 software, then connect (might have to go through multiple COMs). then read from your car ECU and save that file on your laptop. Then, find the cells that correspond to where you are seeing the lean condition (locate based on PSI & RPM)...and adjust those cells by 0.1 at a time. Since you are going lean, increase the value....etc etc. Once you have made changes, load map back to your AFC. Also, I recommend saving it as a different customer name. Then you should be set.....There's far more to understanding the functionality of this unit...I highly recommend reading from SplitSeconds website as well as the tuning guides found here - several times so you have it memorized. Good luck.

 

[TurbomanProtege]

cool thanks alot for the info Im gonna try that sometime this week

 

[slo03.5msp]

You need to add fuel under 3k rpm from values 1lb to 9lb and take some away up top.

 

[TurbomanProtege]

yea I gotta do that, but is it still gonna add fuel even when Im not boosting at 3K rpms. Or is it gonna know when im boosting to add that fuel I adjusted

 

[adirondakkid]

yea I gotta do that, but is it still gonna add fuel even when Im not boosting at 3K rpms. Or is it gonna know when im boosting to add that fuel I adjusted

if you look at the chart, you'll see that when at 3k RPM and in vacuum it should read 10's, and additionally if in vacuum the AFC should not be stepping in at all. Only the cells where you are seeing positive PSI at those RPMS are where you want to add fuel back....again, if you have your wideband connected to the AFC, just open the R4 software, connect to your car ECU when running, and data-log a drive....and take it through the RPM/boost that you're seeing a lean condition. Then you can go back, review the data & determine what cells need to be adjusted.

 

[TurbomanProtege]

ok cool thats what I was trying to figure out if there is cells that have positive psi and cells that are vacuum

 

[adirondakkid]

ok cool thats what I was trying to figure out if there is cells that have positive psi and cells that are vacuum

yeah...the top of the chart starts with vacuum readings, and goes across with decreasing vacuum and then finally going into positive PSI readings. The left side of the chart has RPMs in I think 500 increments.

 

[TurbomanProtege]

ok thats real good to hear will I'll let you know how things turn out