That's the part of the 6-speed that I miss the most. The downside of the manual valve body is that there is absolutely no compression braking. I just don't completely 'miss' shifts like I used to with the 6-speed manual, and a missed shift gets very ugly with a 7,200 RPM redline. The shifts are timed off a shift light, and in my advanced (senior citizen) age, I just don't have the reaction time I used to. It's fun to retain full control, while running the auto trans, but I don't think I have improved consistency all that much. The shifts, controlled by a B&M Pro-Ratchet shifter, are neck-snapping. The trans is built to handle 800HP/800lb-ft. With regard to the full manual conversion, I have a full manual/reverse pattern valve body on the TH400. I'm not sure what benefits are going to be gained with modifications that will probably increase the wear and tear on the trans. I don't know if or what anyone had done to the trans, I was just test driving them after doing some work on them. I found the LS1 cars in particular to be very fast and firm shifts.

I just want to learn more about what is going on here, and Joe certainly seems to have gone deeply into the internals of the auto trans, where I have shied away from them.įirst - I have driven LT1 and LS1 cars with the 4l60E, but never the V6. My Formula was originally a T56 when I bought it new, but shifting on the track was not my forte'. Until I had the TH400 installed in the Formula, I had never driven a performance automobile with an auto trans. If there's something automotive I know little to nothing about, it's an automatic trans. Again, I would call Transgo to make sure. In the end, I think you are going down two separate roads here, you talk about wanting to use a tuning device on your transmission, but then say you are going to install a shift kit that does away with the electronics that the tuner will need.

Not sure it is quite the same as a full manual, maybe it is when you are in the manual gears, I'm not sure, but you keep the electronics in play, and therefore can use your device to tune. I think there are shift kits that allow the transmission to stay in the lower gears until you manually shift, and will allow downshifts at higher RPM's than the stock set up does. Again, you may want to call Transgo, to verify all this. Not sure, but I would think that you would now be getting some codes thrown as well if you disable the 4L60E electronics.

While going to a manual shift is up to you, and I am a fan of making your car the way you want it, if you eliminate the force motor and shift solenoids with the shift kit, your jet dynamic spectrum tuner device will be useless on a transmission that no longer is controlled by a PCM. Maybe an option if you are putting it in a '70's Firebird, but you may want to give Transgo a call to make sure. From what I have read, it makes the 4L60E kinda old school by eliminating the electronics. You may want to find out more about that Transgo stage 3 shift kit. In the end, between the shift kit, the tuner, and a rebuild, you will have a fun 4L60E to drive. It is also easier to install the shift kit while the transmission is on a bench than in the car. A 'Corvette' servo can help hold the 2-4 band tighter, but with a 3.8 engine, I'm not sure you would need this upgrade, but it won't hurt, and can always be added after the transmission is in the car very easily. I would get an upgrade 3-4 clutch pack, and a Beast reaction sun shell to address two 4L60E weak areas as upgrades that must be installed during the rebuild. Since you said you are rebuilding the whole transmission. Since shift kit changes can be installed by pulling the pan, valve body, 2-4 servo, etc, you don't need to take the transmission out of the car. With that being said there are still improvements you can do to further change the shift characteristics past what the tuner device can do, or should I say, in addition to what the tuning device can do. Either way, there is no need to change anything in the transmission itself. In OBD2 cars you need to 'reprogram/flash' the PCM to give it different instructions, which you can do with a handheld tuner device like you have, or send the PCM off to someone who can reprogram it. In the OBD1 days you could change out a chip that did the same thing. All the device is doing is messing with the data tables that the PCM uses to control the transmissions behavior. You don't need to do anything to the transmission itself to get it ready for the tuning device. However, the electronic changes can only do a certain amount, after that you need to change hard parts that come in a shift kit.

So shift solenoid timing can be changed, and the line pressure can be increased by the PCM by changing the milliamp signal the force motor sees which will firm up the shifts. The tuning device can effect the shifts using the electronic adjustments that the PCM has command of. I'm not sure I get your question, but I'll say this.

Transgo shift kit instructions 4l60e