In a message dated 4/18/99 6:13:01 PM Eastern Daylight Time,
tomm@datarecall.net writes:
> The guy told me of another cool mod-ever wonder why your truck runs so
> good in the morning?(when cold). I always assumed it was because our trucks
> just liked the colder air. According to this gentleman, it's because of the
> water temp sensor-being cold on startup! He said to wire up a switch(like a
> double pull one- I think) can put an additional sensor in the washer fluid
> bottle and switch to that one when racing. Kinda like a N2O switch-he
swears
> it really helps, even more than the IAT mod.
I would think that would just be the same as having a 160 degree
thermostat... it would make the truck stay on open loop. No? Running real
rich. Wouldn't that make for an incomplete burn and less compression thus
less horse power?
I would think the reason you run better when the motor is cold is
that the computer is in open loop... thus it is running off the computers
fuel tables that don't change. They have them set this way so the motor will
never run dangerously lean until it is warm enough to go into closed loop
where the O2 sensor takes over. So when the motor is cold it breaths colder
air with its higher oxygen content, it better matches the open loop's rich
fuel table. This makes for a better air/fuel ratio... more oxygen, more fuel,
more power hmmm sounds like a tiny nitrous oxide system : ).
Also on the IAT sensor... you can find a rheostat that will have a
variable ohm load. Once you find the magical impedance you can just read the
rheostats impedance and go out and buy the correct resistor. Instead of using
trial and error with a bunch of resistors. I'd be interested if it works as I
have never heard of that one before.
I owned an 11 second 87 Turbo Buick that used basically the same
motor as the 89 Turbo Trans Am. I had never heard of that screw you are
talking about on the MAP sensor that can vary the fuel curve but, it is
possible.
Charles
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:13:48 EDT