Torque converter lock-up not working for drag racing FIXED!!

[@BurnoutsandRotorblades]

You need to worry about more than locking up! If you do the math on your run your only putting down about 250HP, you know you got more than that - do the math, 5200 RPM w/ 3.73 gears and 26 tall tires going through the traps in 3rd gear (no overdrive) should be around 107 mph. There is some terrible slippage going on.

After my latest trip to the drag strip I looked up what a car with my weight and power should be doing for time and MPH. That's what ultimately brought me to this thread. I don't have my drag sheet right here, but I vaguely remember my 60' was a tenth off from what the drag time calculator said it should be. The gap only widened throughout the run. With that and everything else above, what do you guys think I should be looking for or doing?

 

[pontiacgp]

You need to worry about more than locking up! If you do the math on your run your only putting down about 250HP, you know you got more than that - do the math, 5200 RPM w/ 3.73 gears and 26 tall tires going through the traps in 3rd gear (no overdrive) should be around 107 mph. There is some terrible slippage going on.

I think I have already read that on the previous page..... 🤔

 

[lilbowtie]

The problem is the trans-converter. Without being there to hear and feel it's hard to point a finger. 3400 RPMs on a stock converter footbreaking?? I can only get 2800 RPM on my 4500 stall converter (4400 on trans brake) TV cable??

 

[lilbowtie]

I think I have already read that on the previous page..... 🤔

Glad someone read it - you can take a horse to water but you can't make it drink.

 

[pontiacgp]

Glad someone read it - you can take a horse to water but you can't make it drink.

I don't drag race but I like to see what you guys do to go fast. Like circle track racing you need everything working together so I like to read about the mechanical and technical issues you work on to get the fastest times for what you have to work with.

 

[melloelky]

FTI for the win.

 

[lilbowtie]

 

[@BurnoutsandRotorblades]

The big question is, do you guys think the slippage is coming form the converter or is it internal to the transmission?

I guess I was using the slipping lockup clutch as an excuse to get a new converter because I assume the converter was inefficient. When I had the trans rebuilt, the converter was sent off and "loosened up." I have read that this is done by bending/grinding some of the vanes over to change the stall and can make them inefficient.

I was trying to rule out the trans itself because I had it rebuilt. Do you think it's possible the trans is not right, or maybe is it all down to a TV cable adjustment? I can adjust the TV cable a click at a time and see where it is once that isn't improving anymore.

Any other thoughts?

 

[@BurnoutsandRotorblades]

View attachment 119243

what led you to get that converter? which one is it, what's it behind and in front of, primary use, what do you think?

 

[hoffa65]

The big question is, do you guys think the slippage is coming form the converter or is it internal to the transmission?

I guess I was using the slipping lockup clutch as an excuse to get a new converter because I assume the converter was inefficient. When I had the trans rebuilt, the converter was sent off and "loosened up." I have read that this is done by bending/grinding some of the vanes over to change the stall and can make them inefficient.

I was trying to rule out the trans itself because I had it rebuilt. Do you think it's possible the trans is not right, or maybe is it all down to a TV cable adjustment? I can adjust the TV cable a click at a time and see where it is once that isn't improving anymore.

Any other thoughts?

with that kind of power if your trans was slipping whatsoever you would have toasted it long ago IMO