ITB + TPS

I'll be running megasquirt on this car, so a Throttle Position Sensor (TPS) is needed to tell the computer how heavy your foot is. I grabbed one from the wreckers. I don't recall if it was from a SAAB or an autmatic e30. A lot of cars use similar BOSCH sensors on the throttle body shaft, but be careful since most of them are just on/off switches that tell the computer if the car is at WOT or at IDLE so that the computer can know to either dump as much fuel into the motor as it can, or to switch on the idle control valve. This unit has a pot in it that varies the resistance based on how much you have the thortle open. Note the part number.

If you haven't noticed, I'm a big fan of recycling shit. I fabbed the bracked out of a scrap of aluminum. It was a fence on an old miter box. It's machined perfectly flat on one side, so that mates up against the throttle body housing. The mounting tabs are actually the same exact dimensions as the stock e30 m3 module, but you need to rotate it to get the proper operation of the sensor.

Stuck a o-ring in there to keep the throttle shaft assembly clean.

There it is all assembled. I need to trim down all the excess material around the mounting plate... this is just the mock-up. I hate grinding aluminum...

And here it goes...

throttle closed = idle.

throttle partially open = zoom.

wide open throttle = giddyup motherfucker.