Adding Wideband O2 to Specialist Components EFI - Many Questions
Turbo Mini Forums

I haven't been on here for a while, but you led me on the path to getting my twinky project running well and I've enjoyed it very much for almost a year now. But, as we all know, this thing is never finished!

I took the Mini to a not so local dyno shop and had some changes made to the fuel and ignition maps on my SC ECU. It made more horsepower and torque, but ran lean at speed and stumbled between 2000 to 2600 rpm, so I went back to the maps from SC that we started with. The modified map ran with better Air/Fuel ratios, but that didn't translate to the road experience for some reason(s). Not sure what was going on with the car at that time.

Moving forward to today...

I just installed an AEM Air/Fuel gauge with integral controller and a Boshe 4.9 sensor. I would like to use it to run the car on closed loop for A/F control. I have talked with the folks at SC and know what I need to do to the existing maps to run the closed loop, but am lost at what I see when I open the file. Do any of you have experience with this system that I can ask a few questions and maybe even get some answers?

There are two kinds of people in this world and I'm not sure you're one of them...

I forget the table name, but the one on the basic sc maps was very low scale. I had to mess about with my table to sort it out.

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=565910

I'm a long way from my ecu, but will try and get a screenshot of the settings when I can.

The help files are pretty good.

I spent a while just going through the menus 'off line' to work out what's what.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

When I used it last year I had to scale the 5v input in the setup table for it to recognise the data from the sensor. Simon sent me the table range to use but then I was using an sc sensor.

I can't help with the rest as I found the software difficult to use.

Edited by gr4h4m on 23rd Apr, 2015.

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

Sorry, for any confusion. I should have asked the questions I have about the maps and what I really need to change for my set up.

1. On the Lambda Sensor Input Scaling (V) map I see only two lines when I open it for editing. If I hit the Edit X Axis Breakpoints button, I get 16 lines with the label, Sensor Voltage. Is that where I input the voltage values I want the ECU to use?

2. On the same map, if I hit the Edit Y Axis Breakpoints button, I get two columns of 16 lines with a title of BrkPt. I assume this is where I input the Lambda values I want for each of the voltages entered on the X-Axis. Is this correct?

3. On the Wideband Target Lambda map in the Fuel Closed Loop Control file I got a table of 8 rows and 8 columns after I edited the X and Y Axis and input TPS and RPM values. The Lambda values that SC suggests for that table seem to be high to me. That would result in AFRs above 14.5 almost all the time. I don't think that's going to allow my engine to last for a long time due to lean running damage. I am looking for some direction or suggestions on what might be better numbers to use in that map.

There are two kinds of people in this world and I'm not sure you're one of them...

You say it ran lean before you fit wideband? Have you tryed the maps after fitting the wideband?
Lean 2000-2600 and at motorway speeds sounds like an economical tune to me. But only up to a point if its too lean obviously it wont run
15-16 afr cruising is normal imo

Yes i moved to the darkside

Instagram @jdm_brett

I've got it all installed and the ECU is now working on the closed loop fueling. It seems to be working as I see more consistent AFR/lambda numbers while driving. When I had it at the tuners it was very lean through most of the fuel map (AFR at 15 or more) during acceleration and constant speed under load. The stumble was more like having the fuel switching off and on between 2000 and 2600 rpm. Very disturbing to say the least.

I'll drive it this way for a while and post the results in a few weeks. Thanks for the input guys!

There are two kinds of people in this world and I'm not sure you're one of them...

Hard to believe it's already June 11th. I've been driving with the new O2 sensor in place and the ECU operating with on Closed Loop. Very interesting to watch the AF ratio readout on the gauge while driving. I would have thought it would be closer to the target values in the map, but it's running richer in most conditions. Next is to try small changes to the fuel map and note the results.

Thanks for all the input folks!

There are two kinds of people in this world and I'm not sure you're one of them...

I think you need to get the map very close and only use the correction for smaller amounts

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!