Does anybody know what the RX-8 throttle body pin-outs are and the
   voltages that the sensor/s needs ?
   We are assuming there is a hall sensor in there somewhere being "Denso"
  it
   appears they have done it
   the hard way. We can simply want to use the throttle body as it is out
of
   the box rather than modify it to a cable

   Regards David

   Try this link David
   http://foxed.ca/rx7manual/2003mazdarx8/


   Paul Lamar
   --


   Thanks, got to spend awhile hunting through checking now and see what
it
   got to say :)

   David

  I think Tracy Crook is usng the RX8 TB un his RV8 on a 20B. He seems to
  have
  all the details.
  FWIW.

  Richard Sohn
  N2071U

  Looks like it takes a computer to control it. It looks like
  a closed loop servo system with data fed back from the throttle
  position sensor. It is spring loaded to close to 5 degrees if
  the electronics fail.

  Paul Lamar

--

We have looked at this and it appears that it uses a couple of
hall effect sensors so we have to tread lightly or they will be toast
if we do the wrong thing by them, apparently using these means that it
senses movement rather than specially position and then something has
to hold it and detect movement and so on, TK a friend of mine is figuring
out how we can do this I assume since he used to work for GM in R&D that
he has a good idea or what he's talking about, as he put it why did they
do it the more difficult way? However we are seeing what we can do to get
a workable method, without modifying the throttle body. WE'll see.

Tracy, I know had something or mentioned something was coming but it has
never become available unfortunately, I did ask about it and that was the
answer at the time as far as I'm aware nothing has changed since or to
date.

Regards David

It is not a stepper motor as it only has two wires going to the DC servo.
The 2004 Service Highlights book mentions "duty signal". Sounds like
the typical NC tool analog servo to me. Plus supply voltage rotates one direction
and reverse voltage rotates the other direction.

There are two sensors. One is probably out of phase with the the other.
By this means an angular direction can be determined. When both pulses coincide
and index position is found. Encoder SOP in NC tools. See the diagram.

The probable reason Tracy did not implement it as this function is built
into certain microcomputers used in automotive EFI systems with special
hardware and software to deal with servos. Tracy is a probably using a PIC
that probably does not have this function built in.

I'll consult with my expert on this matter as I am still learning
in the process of updating my NC mill controller.

What do you think Tom?

Also read this.

http://www.aa1car.com/library/throttle-by-wire.htm


Paul Lamar