Quote:
Originally Posted by Compaq888
I thought my car was slow whenever I went WOT because of the torque converter. But my car accelarates faster with OD on. The problem is my car runs so rich that 3rd gear WOT is as slow as accelarating normally in 4th gear. That's a lot of fuel wasted for nothing.
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Whether or not the O/D switch is on is independent of the torque converter. At WOT, the TC generally won't engage until you reach triple-digit speeds or you let off of the gas. Back in the days of running the 'Teg, the TC would engage at top gear around 4000-5000 RPMs (about 110-120 mph). Saturn SL auto-trannies are really wierd -- their TCs engage at wierd times, like 3rd gear at 40 and kick in and out randomly -- never driven something like it. Because of the gobs of torque, the non-turbo diesel ambulances I drove generally kicked the TC-in at 2nd gear. During normal accel from a stop: 1st to about 1500 rpms, shift to 2nd, up to 1300-1500 then a "slide" feeling when the TC kicked-in, drops it 200, then 3rd caught almost right after the engagement. We had O/D buttons too, but it would just keep you out of 4th.
Bottom line: the O/D button does nothing but the equivalent of shifting into "4" or "3" (depending on 5-speed or 4-speed autos, respectively).
SVOboy- The Teg is the same way, it's temperature based to be "ready" (like your constant voltage), then after the engine and trans. sensor warms up, it waits for the right speed. Then it depends on either the throttle input or pressure on it to kick-in. Once it's engaged, I can keep it there until like 1500 rpms then it just lets go as it's programmed. I'd love to know how it decides all this stuff.
RH77