I need a little help. Torque Converter lockup is controlled by the computer right (700R4/stock L98 in 72 pickup with painless wiring). Right now the torque converter will lock up around 45 mpg, and with my tire size (275/50/17) and gearing (3.08) it just bogs the crap out of my truck, especially when trying to go up a slight incline.

So basically can I burn a chip to raise the speed the converter locks up at?

This should aleviate a lot of the poor mid speed driveability I'm having until I get new gears (3.73).

 

Yes, and it is one item that can greatly change the driveability of the vehicle. Not only can the min and max lockup speeds be changed, but the actual TPS% vs. MPH lockup and unlock points can be changed.

RBob.

 

Wait before you drastically change the TCC. Keep it unlocked too much and you can overheat or burn up the transmission. When you go into OD you need to have the lockup clutch applied. Sounds like your truck is going into OD too soon. My old combo was with 3.08 gears in a FullSize Van with a 700r4 and a 305. Mine used to do the same thing, until I bought a B&M governor recurve kit for the transmission. Basically it alters the governor signal going back to the shift valve. Governor pressure has to overcome TV pressure inside the transmission to get an Upshift. If you delay the rise in governor pressure you hold the shift out longer. On a 700r4 you use a combination of weights and springs. The weights depress on the springs, until they overcome the springs and force an upshift. The weights have more effect on WOT shift points while the springs have more effect on part throttle. My old engine would pull strong to about 5,200 rpm. Under 1,300 the engine would not pull very well. Well I have lots of weight, a small engine, large for the application camshaft, and tall gears. The only thing that I changed on the stock 4,400 rpm governor was the springs. The WOT upshifts rose to 4,800 and the part throttle shifts became as follows.

At 20% TPS I datalogged the following.

1-2 @ 2,800 or 26 MPH & 65 MAP (to 1,800 & 75 MAP)
2-3 @ 2,400 or 42 MPH & 70 MAP (to 1,500 & 80 MAP)
3-4 @ 2,200 or 63 MPH & 65 MAP (to 1,500 & 75 MAP)
0-60 = 15 seconds @ 20% TPS and average about 70 MAP

The converter settings were set as follows.

Low Gear Lockup = 30 MPH, Unlock = 28 MPH
High Gear Lockup = 48 MPH, Unlock =46 MPH
The Max TPS for lockup was off the AXKS caprice (.bin).

I was getting converter lock in 2nd, 3rd, and 4th. The engine never seemed unresponsive or lugged down.