Transgo Shift kit?

[SANTEEN]

Just so I make my end clear, I highly suggest a professional install a shift kit.

STFU!!! We got this. But, just in case. How much for a billet valve body with a shift kit already installed

 

[SANTEEN]

Just so I make my end clear, I highly suggest a professional install a shift kit.

STFU!!! We got this. But, just in case. How much for a billet valve body with a shift kit already installed?

 

[JTS VENOM PERFORMANCE]

ttttooooooooooooo much homie, install your blip kit and be happy before you get me castrated:vollkommenauf:

 

[Troy's QC SRT]

Having a spare valve body sure would be good about now.....

 

[VIPR PWR]

Having a spare valve body sure would be good about now.....

I have a spare factory one with a transgo installed...

 

[WOT]

Ok, good to know. Maybe other vehicles I've worked on have that capability. I know the PCM in the Lightning has some way to control line pressure.

So what does the modified trans shift strategy (with a tune) in the PCM actually do? Stock, the transmission doesn't shift nearly as quick/firm as it does with my Roe-tuned SCT program. I realize the shift points are raised, but something else is done with the electronic programming to provide better "performance-oriented" shift quality.

Most tranny's you can adjust the line pressure, shift points, and a bunch of other parameters. With the 48RE, the PCM only directly controlls the governor pressure, the TC lockup and the 3-4 shift point. The WOT shift points are done by tricking the governor pressure with an electronic governor soleniod.

The 3-4 shift is a completely electronically controlled shift as the shift valve is controlled by an electric solenoid. The 1-2 and 2-3 shifts are purely hydro-mechanical with mechanically pressure controlled spool valves and shuttle valves (just like the good 'ol days), but the PCM spikes the governor pressure to make the tranny think it should shift at part-throttle. If, however, the tranny doesn't (hydraulically) want to shift at that point, it won't until the governor pressure is higher. The PCM will try again to make it shift and will learn the trannys behavior (to a point) and will then adjusts the values stored in the governor pressure curve look-up table so that the tranny starts shifting at the correct RPMs.

The 3-4 shift is electronic because our transmissions were made to have 4 gears by basically adding an overdrive unit onto the tail shaft of a 727 Torqueflite 3 speed. The shift firmness is controlled by the Throttle Valve (TV) cable. Since this also controls detent pressure, tightening the TV will make it shift not only firmer, but later for a given gas pedal depression.

The biggest thing done in the PCM to make it shift more responsive is to eliminate the Torque Management (TM). TM works by retarding the engine timing during shifts. It makes the shifts seem a little whimpy, and it also slows the truck down.