[RH77]

I came across something by accident this week, and I wonder if it's worthy of continuing:

Vehicle: '98 Integra Automatic
Manual Torque Converter Switch: On (using battery power)
Auto Trans Selector: Drive (D4)
Ignition: Off

Things got busy on a downhill, curvy road at about 35 mph (with no power steering I had focused on the steering effort and was distracted by a partial lane closure, which resulted in ignition-off while still in TC lockup and in gear -- too busy watching the road completely and not the instrumentation). The obstacle was not a factor and the downhill run continued.

The EOC and manual TC and shifting process has become so routine in my mind, that I no longer have to think about it. So the pattern continued as if it was not interrupted. I thought I had shifted into Neutral for an engine-off coast, but instead went up to D4 (one away from N). Here's where it gets interesting. I sometimes give the gas pedal some pumps during EOC (out of boredom perhaps, since it doesn't do anything -- like to the beat of a song or something -- or "pretend floor it" through yellow lights while coasting-- and no I don't run reds). But this time it did do something interesting...

I heard the open intake resonance during the pedal pumps, then it upshifted from 3rd to 4th. Now the transmission was operating without the electronic control unit, and only by mechanical measures and throttle cable input. The TC remained locked, turning the crankshaft like a manual transmission would. I keyed-back to "on" and the injectors didn't skip a beat. This was great!

Naturally there is compressive deceleration, but it is considerably lessened with WOT to introduce air to pump through. Shifting from D4 to D3 does nothing, but I can shift into "2" and it downshifts, so now I can utilize more aggressive engine braking (not being able to rev match bothers me a little), so I wait and left-foot brake if necessary, until the torque potential is low enough to downshift without too much strain on components. Slowing to a stop, I have been varying throttle inputs to hear engine RPM since the SG and tach are off. The funny thing is that it sounds like a Jake Brake at WOT approaching a stop.

If it looks like traffic will begin to move, I quickly have to disengage the TC and key-on (or else the transmission will perform a double-shift hunt or halt the engine). Then when up at the proper speed, the TC is re-engaged and off we go.

Coming to a complete stop with the unknown timeframe to move again, requires fast action. To prep for start, I have to move the lever from 2nd up to Neutral (a quick push forward stops it there without using the release button or having to look at it), then I flip the TC switch off and the engine stops smoothly. Waiting too long for either step, results in bogging and vibrates the engine similar to keeping a manual in gear too long before pressing the clutch pedal and the engine can be felt "stalling out" with a shudder. On the contrary, performing the measure too quickly will stop the engine and not offer the convenience of just turning the ignition key for instant operation.

So, should I be excited with my new-found "manual transmission" and Jake Brake? (OK maybe not the latter -- the resonator was removed to source warmer air, and was only heard during higher throttle openings (rare), until now when it doesn't use any fuel -- it's obnoxious and confuses onlookers).

Being able to key-on and go is great. If this works well, I imagine having an injector kill button (a simple SPST) on the shifter stalk so I don't lose everything electrical (SG, tach, radio, blower fan, SRS, wipers) and then just release the button to re-energize.

I'm running though it in my mind how this would/wouldn't damage the transmission. Another advantage is that it circulates the engine coolant to prevent hot spots. As I understand it, TC lockup is the safest situation for a transmission -- pumps can turn, and heat doesn't build-up. Downshifting with the TC engaged is generally pretty firm (upshifts too during engine-on), which can have a lasting effect on other torque-sensitive driveline components and the engine itself. AFAIK, having the engine running, or off and locked-into the trans is virtually the same thing.

Am I missing something? Is DFCO a better way to go or just EOC in Neutral and crank the starter? In most cases that I have been using it, is to decelerate and be able to re-start quickly and not have to rev-match back into gear