Additionally, I highly recommend anyone who plans to make decent power with an ST kit run a standalone wideband sensor / gauge as well to ensure proper calibration of your DME lambdas (using the exh. pressure factor table). So that would be 4 bungs in the downpipe
Any products you like/recommend? Preferably one that logs against rpm?
This is where I think something like the AIM data acquisition systems are a no brainer. (or Motec, or Traqmate, etc) Yeah yeah yeah.. they are expensive. But that is relative. Tally up $ spent on a built motor, turbo kit, intercooler, injectors, oil cooler... i'll stop there. Then tally up replacing a blown up motor, blown turbos, and the labor on top of it. All of a sudden that data acquisition isn't so pricey. The AIM MXL2 or (EVO5 with add on dash) is pretty phenomenal at what it can do...
-Programmable warning lights: (The no brainer part)
I can't tell you how many times I've prevented blowing something up because I had a warning light come up telling me something was wrong. INSTANTLY pays for itself when that happens. On the flip side seen lots of people blow stuff up because they didn't have warning lights.
-2 CAN inputs:
Tap into RPM, Coolant temp, brake pressures, steering angle, and a bunch other stuff the BMW PT CAN transmits. Simply done with 2 wires, CAN high and CAN low. More on this below.
-8 analog channel inputs:
Expandable to as many as you want. A/F sensors, temp sensors, pressure sensors, potentiometers, list goes on.
-GPS location:
Tracking for track map display, lap times, predictive timing, etc
-Programmable shift lights:
Gives you green, yellow, red blinking lights so you can build up to the shift point
-3 axis accelerometer:
-Digital outputs:
Use a conditional situation to trigger a cooling fan, or whatever you want.
-Automatic logging:
No need to hit start or anything. It just logs. Programmable conditions as well with that. Ignition on, certain RPM, etc.
-Analysis software is awesome:
Data is exportable to excel if you want to combine with other data to toss into DataZap.
-Wifi connection:
No need to hook up a cord to download data.
All this brings me to MHD logging. MHD is clearly awesome as it is logging parameters that are not broadcasting over the normal BMW CAN. Things like WGDC, timing, etc. It would be awesome if MHD had a CAN stream output. Then more advanced data loggers could record the data. The MHD could log via bluetooth from the car, then a cord could be attached from the data logger to the MHD device (phone, tablet) for the CAN signal. Extraordinary logging and analysis capabilities at that point.
Obviously this is overkill for just logging A/F, just making a point about all the other stuff it can do and save your engine. In other words, running too lean on the pull down the strip, dyno, straight away, etc...? you could have a warning light setup to lift before you kill the motor.
My 2 cents