T56 to A4 swap PCM question

As I am now seriously contemplating a T56 to TH400 swap and have been thinking about the PCM. I'd like to look at any working file to see what you did with the various transmission related functions. As an alternative, I would appreciate a file from an A4, doesn't need to be stock. I could use that as a base for comparison.

Any advice on this would be appreciated.

Rich Krause

Well, if you are going to the TH400, you aren't going to be using the PCM to control the transmission, so all your transmission values will be 0. The older transmissions were controlled by something else (nothing electronic, I know that, but I don't know that much about auto transmissions to give you the correct information) and when you swap one in you just make all the trans data 0. That's all I know, someone with some experience in this will have to help you out more.

Originally posted by DOOM Master
Well, if you are going to the TH400, you aren't going to be using the PCM to control the transmission, so all your transmission values will be 0. The older transmissions were controlled by something else (nothing electronic, I know that, but I don't know that much about auto transmissions to give you the correct information) and when you swap one in you just make all the trans data 0. That's all I know, someone with some experience in this will have to help you out more.

Thanks. That's pretty much what I thought, just wanted reassurance from someone who has "been there...done that".

Rich Krause

Jeff Stevens did it, he's on the Edit list. TH400 is not electronic, that thing is a dinosaur, I had one in my 69 Firebird :)

From what i have read you can just use your t56 computer without having to do anything with it.

Originally posted by 94-3.4
From what i have read you can just use your t56 computer without having to do anything with it.


That's what I thought, just wanted a little info.

Thanks

Rich Krause

I have just completed the swap in dec and you can use your T56 PCM without any problems except for the speedo. The th400 will have a 40 tooth reluctor ring for the speedo and the t56 has a 17 tooth reluctor so the speedo will read about 2.35 times the actual speed your are going. I am sending out my PCM tomorrow to Bryan at PCM for less to have him change the vehicle spped sensor to a 40 tooth pickup like an A4 but leavng the rest of the program untouched. If you have any other questions about the swap e-mail or post and I'll let you know everything I did for the swap.

Matt

Originally posted by Nostang 96z
I have just completed the swap in dec and you can use your T56 PCM without any problems except for the speedo. The th400 will have a 40 tooth reluctor ring for the speedo and the t56 has a 17 tooth reluctor so the speedo will read about 2.35 times the actual speed your are going. I am sending out my PCM tomorrow to Bryan at PCM for less to have him change the vehicle spped sensor to a 40 tooth pickup like an A4 but leavng the rest of the program untouched. If you have any other questions about the swap e-mail or post and I'll let you know everything I did for the swap.

Matt

Matt: thanks very much. I will send you an email. The heads up about the speedo is very useful. I suppose if I just start with an A4 file I can go from there as far as the speedo goes.

Rich