4T65e-HD manual gear control

I've seen a video or two on the interwebz of people putting a GM transmission such as a 4L80e into a truck and controlling the shift solenoids with light switches for the 1-2 and 3-4 solenoids. I would like to implement something similar for our 4T65E-HD transmissions except using an Arduino Uno to control solenoid behavior through a relay board and having manual-only control of gears with a TapShift/TipTronic-style forward/back lever mounted next to the console PRDNL shifter. Pull back to shift up, push forward to shift down (similar to a rally car, Audi, BMW, etc.). However, I have a couple questions about this:

If I were just to control the solenoids through a custom wiring harness extension to avoid hacking into my harness, it would disconnect the solenoids from the PCM and give me control of them. With a stock tune in place, would the computer freak out at the transmission changing gears when commanded by me, and not when the computer is expecting? Would I need to use the PCM from a manual-transmission car such as a V6 Camaro?

If I disconnect the transmission I only get two gears, but shifting between then with the PRDNL shifter is incredibly quick and smooth, almost to the point of feeling like a modern dual-clutch transmission. What table values would I have to alter to mimic this behavior?

Are the line pressure solenoid and TCC solenoid voltage-based or PWM controlled? I'm thinking I would have TCC engage after the car has been in 4th gear for 20 seconds, or set it up to work similar to a manual car in that it is locked up all the time except when changing gears, which would allow more precise throttle response for stuff like autocrossing or road racing since there wouldn't be a fluid linkage between the engine and wheels as would be the case with an un-locked TCC. Or am I thinking about that wrong?

If I can get this working and *viable* and find enough internal trans wiring harnesses to make more extensions I might consider selling some of these as plug-and-play kits for people who want a "manual" in their car but can't afford an F40 swap or Fiero Getrag swap.

Soooo, something like the TCM 806 found here?:
http://www.magnashift.com/magnashift_controllers.html

If you're worried about the computer not being set up for a manual, it's actually a pretty simple change. You just need to take the bin file, open it in tiny tuner, and then you are given the option to change what transmission the PCM thinks it has (0 is manual IIRC).

Karma wrote:

Soooo, something like the TCM 806 found here?:
http://www.magnashift.com/magnashift_controllers.html

Storebought is lame.

matt270avian wrote:

If you're worried about the computer not being set up for a manual, it's actually a pretty simple change. You just need to take the bin file, open it in tiny tuner, and then you are given the option to change what transmission the PCM thinks it has (0 is manual IIRC).

Hmm, darn. I'll still have to have HPTuners to write it though, right? I have access to a computer with HPT, I just have to get a license for my car.

100percentjake wrote:

Karma wrote:

Soooo, something like the TCM 806 found here?:
http://www.magnashift.com/magnashift_controllers.html

Storebought is lame.

Sure, but if you compare the cost and time messing around to make one vs. buying one that has already been sorted and even comes with the harnesses/gauge gear indicator readout/launch control... There is a tipping point as to which is worth it. It just comes down to how much you value your time. I mean if you want to make one because you enjoy the experience of making something then go nuts; I can appreciate that.

True, but $350 + $100 to tune the PCM to ignore the transmission is a fairly hefty investment vs a $40 Arduino, $100 tune, and some spare time.

Operating inline, I'm not sure that such a device would need the PCM to ignore the transmission.  I believe the PCM will happily send its info, and the controller will just send what it likes. (as long as feedback from the transmission is maintained.)  I think the fast way to get an answer to that might be to contact those guys who sell that magnashift, pretend you are interested in buying one, and ask if the PCM needs to be reprogrammed. I'm actually pretty suspicious their device isn't just an arduino itself in a box.  An ideal world would be no PCM programming and the ability to turn on and off the full manual control mode at will.

I'm definitely going to contact them, if not just to confirm that it will work for FWD configurations (who knows? There could be some weird gotcha between the 4t65 and 4l65) because, really, that's NOT a terrible price for something like that.