Since it's been getting colder around these parts, my friend and I have been looking for something to keep us busy since we don't have all that much work to do on our "real" cars, so we've been kicking around the idea for this swap and trying to figure out if it's possible..

I've got an '01 pontiac grand am gt as a daily driver with 180k on it. It's got the POS 3400/4t45e drivetrain, intake gaskets have been replaced numerous times, spark plug has blown out, trans has been rebuilt etc... The drive train probably needs replacing soon, and the body is in good condition so I don't really want to junk the car..

We've done a bunch of 3800 swaps into fieros including his turbo'd 3800 fiero that gets the everliving **** beat out of it daily, and these things have been holding up great. I've got access to cheap N/A 3800/4t65e combos and I'd like to swap this into my car instead of replacing the currrent drive train with the same thing.

We're not worried about the wiring or mounts etc, we're used to all that from other swaps... However we're trying to make sure the PCM/BCM will communicate correctly with the different drive train setup.

The 00+ monte carlo SS came with a 3800/65e combo, so the PCM runs the 3800, but has the BCM data stream of the 3400, which sounds like it'd work well in my case.

My question to you guys more familiar with this stuff than me, Is the PCM-BCM data stream software or hardware related... Meaning, could I take a run of the mill 3800 ecu (gp...) and flash the Monte SS bin file and have the correct 3400 bcm data stream?

The only interface the 01 ga has to the PCM is that data stream, so if it's just software related I'll be able to pickup any 3800pcm and flash the bin of a MCSS.

I've used efi live on my c5 and fbody's over the years, but it's been a while since I've messed with the obd2 stuff since my friend and I both have AEM stand alones. So I'm unsure of the whole data stream stuff.

Thanks for the info guys

Jim

 

anyone?