95 LT1 PCM help needed

[SubZero350]

Doing an LT1 swap into a Fiero for a gentleman using a 4T60-E transaxle. We have the mechanicals pretty much covered, but I have a few questions about the LT1 PCM. I have tuned a couple of these systems in the past using TunerCat, but there are a few more things I would like to do with this car.

First off, the 4T60-E does not have a trans range pressure switch like the LT1 PCM is going to want to see. I have kinda found a way around this elecrically, but the PCM is only going to see P, R, N, OD... If the driver selects D, 2, or 1, the PCM is still going to see OD because the 4T60-E's gear position switch is not directly compatible with what the LT1 PCM wants to see from the trans range pressure switch it was designed to work with. My question here is: is there any place in the LT1's programming that assigns gear selection based on inputs from the trans range switch? If I could alter these tables, I could make the LT1 PCM more compatible with the 4T60-E's external position switch.

Secondly, the 4T60-E does not have a PCS or 3-2 downshift solenoid... I could pacify these circuits from the PCM by using resistors, but I would much rather disable the trouble codes. Also, I think there might be an issue concerning the stall speed of the torque converter and what the PCM is going to interperate as a slipping transmission; anything I can do to prevent the PCM from setting a slip code?

Lastly, the 4T60-E trans has a 30 pulse per wheel revolution VSS whereas the 4L60-E has a 40 pulse per driveshaft resolution VSS sensor. While TunerCat appears to let me adjust the VSS calibration tables, is there anything I should be concerned about?

Hex addresses would help for any of the above as I have CATS TDF Editor and can add them to my existing $EE .tdf. Better yet, if anyone has a detailed disassembly of the $EE code and would be willing to share it, I would greatly appreciate it.

Once I get the car going I will be happy to share the results to the board. Thanks in advance.

[sean]

just use a 4t80-e ;D or go with a 4t60

[SubZero350]

Actually, I think the 4T65-E would be a better match but the customer already has paid for a rebuilt 4T60-E so that is what he wants in the car.

[sean]

well ive got to say time to tell the customre to bad. you can put the 4t65 internals in the 4t60 case. and i dont see how your going to get the trans to behave properly. its either that or you pirate the control code from a 4t60e control and splice that into the 4l60e program in the lt1 pcm. i do belive however the TCI i think has a 4t60 controleer i know there controller can run a 4l60e so maybe they could be of some assitance.

im out of ideas.

[SubZero350]

sean, the 65-E has a different case than the 60-E so you can't change out the electrical internals that make the difference between the two trannys. besides that, I think I have already figured out how to make the LT1 pcm work with the 60-E anyway. The customer is on a budget and cannot afford expensive aftermarket ECU's and I don't blame him. By the time be would buy that thing he could afford a rebuilt 65-E but that is the problem. He has just enough money to do the swap using the parts he has now, no extra.

The biggest concern I have at this point is the OBD1 LT1 PCM high stall problem. Even if I find the lowest stall available for the 4T60-E, it is still a 10" converter designed to work with a V6, unless I find a catty TC, like that would be easy.

Well I will find out what happens soon as this thing is going together.

[sean]

well if its the stall your worried about i dont think its a big concern. ill poke around the lt1 code but i dont thinks theres anything that would determin slip until the cnverter as locked anyways. ive tunned alot of lt1's with 3500stall converters and ive never gotten a slip code