Torque converter
Torque converter
Has anyone modified the torque converter at all on the 722.6 gearbox? I know you can get some higher stall converters however those would mainly be useful for engines that have a higher RPM/power band much like the petrol engines that are bolted to these transmissions.
I only ask as there is sometimes a bit of delay when pressing the throttle on my car, I have read that when at above 75% throttle the converter is actually open and no locked or slipping. I was just wondering if anyone had modified the converter in any way to make it lock up sooner to get a better launch at all?
Here is the graph showing when it locks up/when its slipping and when its locked, it makes sense for it to be open when at above 75% to allow for traction to be put down on the road, however I don't know if there is any way this can be modified simply:
![[Image: 7226torqueconverterlockupfunction.jpg]](http://i209.photobucket.com/albums/bb196/splintersAMG/7226torqueconverterlockupfunction.jpg)
It also looks like the kick down button (pressed when past 100% throttle) simply changes the box from open to slipping on the torque converter:
![[Image: 226963d1327352477-coasting-downhill-slip-examples.jpg]](http://mbworld.org/forums/attachments/c-class-w204/226963d1327352477-coasting-downhill-slip-examples.jpg)
Hi all,
Has anyone modified the torque converter at all on the 722.6 gearbox? I know you can get some higher stall converters however those would mainly be useful for engines that have a higher RPM/power band much like the petrol engines that are bolted to these transmissions.
I only ask as there is sometimes a bit of delay when pressing the throttle on my car, I have read that when at above 75% throttle the converter is actually open and no locked or slipping. I was just wondering if anyone had modified the converter in any way to make it lock up sooner to get a better launch at all?
Here is the graph showing when it locks up/when its slipping and when its locked, it makes sense for it to be open when at above 75% to allow for traction to be put down on the road, however I don't know if there is any way this can be modified simply:
It also looks like the kick down button (pressed when past 100% throttle) simply changes the box from open to slipping on the torque converter:
If you're talking about a hesitation when starting from a stop, that's probably on the engine's end. The valve body probably prevents any possibility of the TCC engaging in 1st.
raysorenson
08-28-2015, 03:32 PM #2I'm not sure if any of the aftermarket controllers slip the clutch at all. Also, I think the later gearboxes will allow lockup in 2nd but wait for others who know more to confirm.
If you're talking about a hesitation when starting from a stop, that's probably on the engine's end. The valve body probably prevents any possibility of the TCC engaging in 1st.
(08-28-2015, 03:32 PM)raysorenson I'm not sure if any of the aftermarket controllers slip the clutch at all. Also, I think the later gearboxes will allow lockup in 2nd but wait for others who know more to confirm.
If you're talking about a hesitation when starting from a stop, that's probably on the engine's end. The valve body probably prevents any possibility of the TCC engaging in 1st.
Thanks for that, I believe the aftermarket controllers increase the pressure in each of the clutch packs - I know that the torque converter is a viscous coupler so I guess its a case of changing the torque converter with a slightly different impeller setup. I know you can get higher stall torque converters but these would only be good if the engine were to make power higher up the rev range than stock.
I will look into possible options but I have a feeling I would need to swap out the torque converter for a higher performance version - will see what its like with a stock converter and an aftermarket controller.
(08-28-2015, 03:32 PM)raysorenson I'm not sure if any of the aftermarket controllers slip the clutch at all. Also, I think the later gearboxes will allow lockup in 2nd but wait for others who know more to confirm.
If you're talking about a hesitation when starting from a stop, that's probably on the engine's end. The valve body probably prevents any possibility of the TCC engaging in 1st.
Thanks for that, I believe the aftermarket controllers increase the pressure in each of the clutch packs - I know that the torque converter is a viscous coupler so I guess its a case of changing the torque converter with a slightly different impeller setup. I know you can get higher stall torque converters but these would only be good if the engine were to make power higher up the rev range than stock.
I will look into possible options but I have a feeling I would need to swap out the torque converter for a higher performance version - will see what its like with a stock converter and an aftermarket controller.
![[Image: 722%206%20torque%20converter.jpg]](http://www.mercedesdismantlers.com/722%206%20torque%20converter.jpg)
That's a 722.6 TC. See the frictiony bits in there?
raysorenson
08-28-2015, 04:29 PM #4Yes, the torque converter is a viscous coupling, but those chartngrafs are about the TCC, torque converter clutch. It's got an actual clutch in there in addition to the fluid coupling. The nice thing about a good TCC is that if you increase the stall speed, you can still lock up the TCC when you're cruising to stay efficient.
That's a 722.6 TC. See the frictiony bits in there?
![[Image: 212512d1308408174-hypermiling-bad-transm...verter.jpg]](http://mbworld.org/forums/attachments/off-topic/212512d1308408174-hypermiling-bad-transmission-722.9-torque-converter.jpg)
raysorenson
08-28-2015, 04:31 PM #5Yes, the torque converter is a viscous coupling, but those chartngrafs are about the TCC, torque converter clutch. It's got an actual clutch in there in addition to the fluid coupling. The nice thing about a good TCC is that if you increase the stall speed, you can still lock up the TCC when you're cruising to stay efficient.
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