Freezing the Slushbox. Torque Converter on-demand lockup switch. - Page 13 - Fuel Economy, Hypermiling, EcoModding News and Forum

orange4boy · 10-16-2009, 10:11 PM

I'll ditto Christ on the above.

I have not had any TCC slippage as far as I can tell. If it slipped, my rpm would race up a bit or a lot. Nada. I'm not drag racing here, but hypermiling so normally the load is low anyhow.

It still shifts fine lockup or not. I have noticed it shifts at a decent point when I use more throttle but too soon if I am light on the throttle, hence the "manual" shifting.

I should point out that TCC lockup switches are used in trucks towing heavy loads to save the transmission from overheating and to increase FE on the highway.

I have merged onto the highway and that is much better with the lockup engaged AFAIC. If the TCC is not slipping it can't possibly be damaging anything. The whole torque converter would have to come apart. Not likely if it does not come apart under any other loads. It acts on the far outer edge of the TC where the mechanical advantage is the highest so load is lowest. If the clutch friction material wears off then I would have to replace the TC but since there is roughly as much slippage as stock when it engages it should be just fine. I'm willing to take the risk which I think is very small.

I have increased fluid pressure by adjusting the throttle kick down which should help keep it locked up nice and tight.

Quote:

I was also under the impression that the TCC only unlocks under load to increase engine RPMs, effectively providing more power to the transmission. I'm fairly certain the TCC can hold at fairly close to max output, but it's not like we're accelerating at WOT all the time.

Yup. I believe it's a driveability / power issue. Most people want/expect the torque right now and care less about FE but we like the low rpm, high throttle angles.

Christ · 10-16-2009, 10:20 PM

I should also note that I pointed out another fact to someone else in another thread regarding this:

When you're driving normally, without a TCC lockup switch engaged, you're normally locking and unlocking the TCC MORE and under heavier loads than when you can control it.

In many cases, every time you let off the accelerator too far, it unlocks the TCC, anticipating a brake application. Next, you hit the gas again, with high load at 70 MPH, and it must now decrease the engine speed under high load/tension, to match the speed of the output side of the torque converter.

orange4boy · 10-17-2009, 02:58 AM

Important note for transmission modders: Some transmissions use a pwm signal to give different duty cycles to the TCC. This allows some slippage. I found an article that explains how to do it properly although you will have to modify it to get the on demand lock up:

A604 transmission: Chrysler, Plymouth, and Dodge Four-Speed Automatic Transmission Torque Converter Disabling(not really disabling but disabling the slip)

Adding a manual switch will actually reduce wear on your TCC and reduce heat build up in your transmission.

Christ, is this what Cara has?

Christ · 10-17-2009, 09:53 AM

No, sir. I have a 3 speed hydraulic tranny, but I'm not sure if there's PWM to the solenoid or not. Doesn't really matter, as the article states, PWM is there to allow slippage so that the engine doesn't bog, because the TCC engages basically "too soon" for normal people. Once it's fully locked, I believe it's still 12VDC applied voltage.

Still haven't had time to play with mine, though. I gotta drive all over hell's half acre today, and I'm trying to get some money around for a deal on a 1994 Ninja 250 with some gear. Selling the box off my 'Coma today, so I'll have the money for those Metros I'm looking at. All of these things, of course, being on my mind all at once, makes it quite easy to forget to hook a 12V switched power lead to the solenoid.

orange4boy · 10-17-2009, 04:41 PM

Quote:

Once it's fully locked, I believe it's still 12VDC applied voltage.

Oops. I edited the incorrect statement out.

Quote:

All of these things, of course, being on my mind all at once, makes it quite easy to forget to hook a 12V switched power lead to the solenoid.

Ahh.... So many mods, so little time.

IsaacCarlson · 10-18-2009, 10:34 PM

I am still trying to figure out which TCC solenoid does what. I have found info that says the regular solenoid controls full lockup and the pwm controls part-lock, and I have found info that says that the regular solenoid enables the pwm solenoid, and I have found other sources that claim the pwm solenoid controls how hard the regular solenoid hits. Which, if any, are right? Does anyone know??? I think this is the only thing holding me back right now. If you know, PLEASE SHARE....

Ike

orange4boy · 10-22-2009, 04:19 PM

All I can say is WOW!

Latest mixed tank fill netted 30.2mpg up from an average of 24. I can hardly believe it but there it is. Also got a record tank distance of 818km/508mi.

That's almost a 26% improvement. It may settle down a bit on the next tank but we will see. I doubt most people would get the same improvement because I live in a very hilly area where the slushbox was labouring up these hills at low speed, high RPM and I could never get into OD. Now I cruise the flats at 30-35 locked up in OD and do most of those hills locked up in 3rd or OD.

30mpg combined! So happy!

Formula413 · 10-22-2009, 09:28 PM

That's impressive, I might try this on my Escort.

Christ · 10-22-2009, 11:28 PM

Quote:

Originally Posted by orange4boy

All I can say is WOW!

Latest mixed tank fill netted 30.2mpg up from an average of 24. I can hardly believe it but there it is. Also got a record tank distance of 818km/508mi.

That's almost a 26% improvement. It may settle down a bit on the next tank but we will see. I doubt most people would get the same improvement because I live in a very hilly area where the slushbox was labouring up these hills at low speed, high RPM and I could never get into OD. Now I cruise the flats at 30-35 locked up in OD and do most of those hills locked up in 3rd or OD.

30mpg combined! So happy!

What the hell do you think I've got here? :P

The EOC I think is really going to pay off, once I start remembering to turn the stupid key back on.

If the EOC really works out, I'll probably (think about) install(ing) a kill switch.

almightybmw · 10-23-2009, 03:00 AM

I've been messing with the truck of late, but the GP could really use this. MY wife doesn't speed to engage a higher gear for lower rpms (she does coast a lot, and not accelerate fast) so she tends to net about 1mpg less than I (although I might be able to do better, as I have a slightly heavier foot than her). With the lock she could lock it in 2nd or 3rd for the majority of speeds she drives; and I doubt a switch would be out of her range of driving skill.