Freezing the Slushbox. Torque Converter on-demand lockup switch. - Page 16 - Fuel Economy, Hypermiling, EcoModding News and Forum

brucey · 10-26-2009, 12:41 AM

I believe most automatics today have a smaller transmission cooler built into the radiator. This is two fold. It moderates the transmission to some extent. Warming it up in winter sooner, and keeping it closer to the water temperature for the cooling effect in summer.

I have my external plugged in line with the stock one. Like I said, for 40 bucks its worth it for piece of mind. I need to also get a gauge on mine. :/ I might try this for the lezzy afterwards too.

Formula413 · 10-26-2009, 05:36 PM

Quote:

Originally Posted by RH77

Excellent point. In my application, the trans cooler is essentially built into the radiator. I have it blocked and coolant temps get high -- I should also worry about the trans.

I'm also running about 80% synthetic fluid, which should hopefully handle the extra heat.

Trans temp is that one setting that's missing from the SG-II for monitoring. It may be an X-Gauge add-on, but I don't believe there's a sensor for it.

Trans temp is a Ford-specific X gauge so I can see it on my car. Typical highway cruising is about 176* or so. Hills wreak havoc on it. I took a road trip through Pennsylvania back in June and was seeing temps as high as 230*.

And you are right to be concerned about the effect of the grill block. I had a full lower grill block on over the winter, and when the weather started to get warm coolant temps were about 5-10* above normal, but trans temps were up about 25*. What brucey pointed out is right on, with the coolant and trans fluid sharing the radiator the coolant is actually heating the trans fluid to an extent.

orange4boy · 10-26-2009, 06:22 PM

Quote:

Have you been watching the transmission temperature? Thats the only thing I'd be worried about in doing something like this. I haven't seen it mentioned, but I thought that was the reason most transmissions dont always have the torque converter locked, in high load settings it causes a ton of heat.

Exactly the opposite is true. The TCC lockup reduces heat build up in an auto transmission. Most of the heat generated is from fluid friction in the TC. Lock it up and the TC is disabled, eliminating all that fluid friction.

The TCC unlocks under high load situations to give you more torque from the torque multiplication action of the TC. If you have enough torque with the TCC locked at a given load it is far more efficient to be locked up than not. Just like a manual trans, if you don't have enough torque, downshift. Problem solved.

The TCC lockup really just turns your auto into an auto shifting manual transmission without a foot operated clutch.

Christ · 10-26-2009, 08:06 PM

Explained perfectly.

IsaacCarlson · 10-26-2009, 08:20 PM

now I am not so sure....I have been wondering if downshifting to the next lower gear would be better than just unlocking the TCC and getting a little more torque? If the fuel used would be the same then I would leave it locked...just wondering. it would be nice to have the pedal for when I want to hit it hard though....still not sure how to deal with both TCC solenoids.

Christ · 10-26-2009, 08:21 PM

Try monitoring the solenoids with LEDs to see how they react to different situations. It will give you a better idea of what's going on than any of us can.