Using XFI for torque converter lock up
We used this feature some when we ran a 200R4 with a lock up converter. I assume you're using the factory speedometer sensor. There is a lot of filtering (averaging) in the XFI and the factory speed sensor, so the harder you accelerate, the more the XFI will lag behind.
The first thing you have to do is set up the XFI so that the speed recorded is the actual speed of the car. To set this up, from the main menu, go to 'View', 'System Configuration', 'Sensor Calibration' and finally 'Rate Sensor Calibration'. Using the stock 3.42 gears, and 28" tall slicks, we came up with 750 for the 'Driveshaft RPM calibration' and 1482 for the 'MPH calibration'. As long as were going at a static speed, the XFI matched exactly a GPS at 30 and 60 MPH. However, as I said above, there is a lot of averaging. XFI would show only 110 MPH when I was really going 140 MPH.
The next step is to tell XFI what speed you want to lock up the converter. To do this, from the main menu, go to 'View', then 'TCC Lockup Parameters'. Set the minimum TPS for lockup, minimum MPH for lockup and the TCC lockup delay. The converter will lock up once the minimum MPH is achieved and after the delay. I believe the minimum delay that XFI will save is 0.1 seconds.
If you're only going to use this feature for cruising it will probably work fine. If you want something for the track, contact Cal Hartline. He sells a speedmotor sensor that will work with XFI and is much more accurate.
Hope this helps.
