DK01

Why isn't there a fuel management system that can automatically adjust the tuning based on a set AFR rate, say 12.0? Just like what the stock ECU is doing during close loop and keeping the AFR around 14.7. Are there any companies attempting something like this to help make tuning a lot easier? Just curious..

soros151

Because there aren't any? Its called Engine Management because u tune it to be like that, also if there is a device maybe it is Dezod's Black Box.

mike6789k

good question... it could be as simple as just altering the 02 sensors signal... so the ecu THINKS it's at 14.7, when it really is at 12.0

OuterHeaven

Well it has been talked about and there is an AFR target map in the greddy e-manage ultimate. But no one uses this all the time because if say the o2 sensor started to malfunction or is no longer calibrated (as in when u think it is 12:1 AFR but really it is 15:1) bad this can happen. Now if you are still willing to do this then here is a good idea of a way you can modify an e-manage to do exactly that http://www.srtforums.com/forums/showthread.php?t=158399.

This gets pretty in debt but definitely shows a possibility of making it work. Also the creator of the post apparently actually got this working also. In reality I would make a "base map" that was already close and then just use an AFR target map to adjust on the fly and that is what a stock car REALLY does. I may do this in the future but for now I have an e-manage and hopefully a dezod black box/URD calibration unit soon.

OuterHeaven

This is EXACTLY what the dezod back box does... This only works during closed loop. During open loop (WOT and high MAF reading above 3500 RPM) the ECU calculates how much fuel base off the MAF sensor signal and ignores the o2 sensor.

ERIC-TC

There are more evils ways of doing this but it takes a lot of time. You can make an emamage map that runs of the wideband 02 input and add fuel when you are under your target A/F. The problem is that the A/F is not a steady thing as you are driving it sort of fluctuates and when you decelerate and when the BOV pops open the A/F goes crazy for a little bit -you really do not want to add injector duration during these periods.

Once you are in open loop it really is not a big deal to adjust fuel with a fuel map that runs of MAF or PSI.

DK01

I was looking over at YSTC forums and lobux racer pointed out this thread from the lexus forums. There is a guy that is making a air/ fuel controller to tune itself and looks like he may put it into production in the future. If he can get this thing in production I think it will be a great idea making tuning easier on cars in general. I'm just curious why aren't companies making something like this when this can be a big hit in the performance world. When this one guy can come up with something like this basically by himself. Here is the link http://www.clublexus.com/forums/showthread.php?t=249458

BOXMAN

watching

soros151

This looks a lot like the one from Dezod's. This is so cool.

mike6789k

then why does the black box cost what it costs... ill bet anyone with some electrical knowledge can draw up a schematic and put that baby together!

OuterHeaven

Ya but this has an onboard map sensor, computer interface, and a program to program it with. This is not just a simple electronic device. This is pretty much fully digital with a processor of some kind, I am sure. Anyways someone would have to know the workings of the stock sensor very well because it still would be pretty difficult to simulate the current and voltage of the sensor.

mike6789k

wrong. http://www.bobblick.com/techref/proj...sim/o2sim.html

mike6789k

the map sensor is a binary sensor on the black box (boost? yes. or no.)

computer interface ill give some credit too (the program is the same... how can you have an interface without a program)

and the rest is probably similar to that sim i sent you...

mike6789k

another one, http://www.mkiv.com/techarticles/oxy...sor_simulator/

even simpler...

mike6789k

and i suppose all you need for the interface is an fpga chip... that will control the resistance (a virtual pot almost..) so you can adjust the afr value through a computer an upload that "flash" to the chip

OuterHeaven

Here is the problem... those are all for narrowband 1V sensors. I am not trying to discourage you from this but the stock wideband gets its reading from the voltage AND current. These change based on different conditions and the resistance is not the only variable. I know our sensor is a 4 wire but it works in a similar fashion to a 5 wire pump cell (http://www.wbo2.com/lsu/default.htm). At the bottom of the page it has a nice short explanation of how a 5 wire wideband works. The 4 wire is different but still similar. In actuality the 4 wire is lesser known and "newer" and would take a lot more research.

Sorry I do not want to sound like I am raining on your parade just trying to warn you. Also you can always take a look at their schematics for their product on how they read LSU sensors or build a cheap wideband gauge/logger for cheap like I did .

mike6789k

OuterHeaven - that's awesome man!

but isnt the o2 sensor that the ecu uses to tune NARROWBAND?

im pretty sure it is... or else people would be hooking up their uego displays to the stock sensor without needing to buy the whole setup...

OuterHeaven

It IS a wideband but it is a newer 4 wire sensor and all the uego displays use a different type of sensor. This is why the front (~$200) is twice as much as the rear o2 sensor (~$100). So the front is a wideband while the rear is only a narrow.

OuterHeaven

Now what I really want is the dezod black box/URD calibration unit to have a wideband output so people could use the stock wideband to tune and hook up a display. That right there almost makes the black box worth it by itself.

mike6789k

are there any wideband displays that will accept the new 4 wire input? any converters?!