AC on Power Increase

[Wayne Cox]

At 12:08 AM 9/4/2003 -0500, you wrote:
>For some time I have noticed performance at full throttle seems somewhat
>stronger,  especially a held shift from first to second at 7500 RPM there
>is a definite lunge forward when the Air Conditioning is on. (Have
>Automatic by the way).

Any perception that it is stronger with the AC on is just in your
head.  what you're feeling is it returning to normal power when the ECU
finally switches off the damn compressor at WOT.  Lift for just a split
second though (ie: change gears) and f**ker is back on.  I'm surprised I
never wore out an AC switch from manually cutting it of & on constantly.

Every Classic and NX I've owned or driven bogs down like MAD with the AC
on.   It's like you're dragging an anchor around behind the car.  When the
ECU finally (reluctantly)  cuts the AC, it's like the anchor chain broke
;)  The UOR crank pulley supposedly helps a lot with this.

Years ago when JWT was first working on SR20 ECUs with some list members, I
suggested they change the AC programming in the thing to cut the AC more
readily, and once cut to keep it off for a minimum amount of time (like 4
seconds) to eliminate the between shift bog, but it didn't heppen.

>Is there a way to trick the ECU into thinking the AC is on but isn't? to

Yeah, it's real easy to experiment with.  Just pull the fuse on the block
under your dash (4th down on the left, IIRC - just did it last week)  This
disables the clutch on the compressor so it can't kick in.  But the ECU
controls things as if it's running.  Your fans will stay on most the
time.  This is an old SR20 trick for autox and drag racing for extra
cooling while waiting for your run.

    -Wayne    '91 NX2k - '93 NK2k - '93 SE-R - '92 SE-R parts car