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Torque converter - Printable Version

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+--- Thread: Torque converter (/showthread.php?tid=6693)

Torque converter - m1tch - 08-21-2015

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:

[Image: 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]

RE: Torque converter - raysorenson - 08-28-2015

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.

RE: Torque converter - m1tch - 08-28-2015

(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. 

RE: Torque converter - raysorenson - 08-28-2015

Yes, 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.

[Image: 722%206%20torque%20converter.jpg]

That's a 722.6 TC. See the frictiony bits in there?

RE: Torque converter - raysorenson - 08-28-2015

Yes, 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.

[Image: 212512d1308408174-hypermiling-bad-transm...verter.jpg]