3.8 to ls wiring questions...
3.8 to ls wiring questions... Okay...I've looked over this board, and just can't seem to find the info I'm looking for anywhere. Sorry if this is a repeat request. 
I have a NICE, low-mile 1996 Firebird with the lame v-6 that I'm in the process of building a force-fed 427 (stroked lq4/l92 heads) for. Now, before any lecturing starts on the benefits of just buying a factory LS car (and modding it) begin, let me just state that the ONLY reason I'm keeping this car is that it has been in the family since new, and holds a certain sentimental value to me. That, and the fact that I'm already big $$$$ into parts for this vehicle.
So..all that being said.. what is the best year of LS harness to use on this project? I have been told that the 02-newer ecu's have more memory/functions in them, and as such are much more feature-laden when it comes to tuning. I also bought HP Tuners, and apparently some of the newer ecus support "real-time" tuning...which would be very nice to say the least. In addition to running roughly 15lbs of boost into the soon-to-be monster, I will be converting to a built 4l80e.
So, I guess I'm wanting to know what ecu, and year of wiring will be best for this setup...without having to resort to stand-alone injection. My desire is to have no issues with the ecm and bcm/guages and I'm just not sure where to go from here. I also want to retain A/C and cruise, etc. Any input as to pros/cons of different year ecus and wiring harnesses would be very helpful. Also, if anyone on this board has actually DONE the wiring swap/mod for this particular vehicle, I'd like the opportunity to "pick your brain" a bit over the phone or via email. Thanks!
I have a NICE, low-mile 1996 Firebird with the lame v-6 that I'm in the process of building a force-fed 427 (stroked lq4/l92 heads) for. Now, before any lecturing starts on the benefits of just buying a factory LS car (and modding it) begin, let me just state that the ONLY reason I'm keeping this car is that it has been in the family since new, and holds a certain sentimental value to me. That, and the fact that I'm already big $$$$ into parts for this vehicle.
So..all that being said.. what is the best year of LS harness to use on this project? I have been told that the 02-newer ecu's have more memory/functions in them, and as such are much more feature-laden when it comes to tuning. I also bought HP Tuners, and apparently some of the newer ecus support "real-time" tuning...which would be very nice to say the least. In addition to running roughly 15lbs of boost into the soon-to-be monster, I will be converting to a built 4l80e.
So, I guess I'm wanting to know what ecu, and year of wiring will be best for this setup...without having to resort to stand-alone injection. My desire is to have no issues with the ecm and bcm/guages and I'm just not sure where to go from here. I also want to retain A/C and cruise, etc. Any input as to pros/cons of different year ecus and wiring harnesses would be very helpful. Also, if anyone on this board has actually DONE the wiring swap/mod for this particular vehicle, I'd like the opportunity to "pick your brain" a bit over the phone or via email. Thanks!
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
Well the 99-02 PCM`s are all the same. 98 is the less supported, slower PCM year. So I would go with 99-02 wiring PCM. Magnus has done a v6-LS1 swap and has a good write up posted here http://www.dxsoftware.com/magnus/
Here is my Swap Thread, aswell as some excellent wiring info..
https://ls1tech.com/forums/conversio...to-95-z28.html
https://ls1tech.com/forums/conversio...to-95-z28.html
Here is my Swap Thread, aswell as some excellent wiring info..
https://ls1tech.com/forums/conversio...to-95-z28.html
https://ls1tech.com/forums/conversio...to-95-z28.html
I just picked up a 98 LS w/auto trans engine harness today, and am going to see if I can make it all work with a 00 ECU. Any idea (just off the top of your head) what the main differences are between the 98 harness and the 00 style harness?? Just thought I'd ask, since you've already been through the whole mess.
Thanks for your help.
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
check out the pcm re-pin thread in the PCM/programming forum. You will have to re-arrange most of the pins in the PCM connectors to make a 98 harness work with a 99+ PCM as almost all of the wires connect to a different pin.
Thanks. I'll search for it and see what comes up. To thicken the plot a bit, I just picked up an under-dash harness with all modules from a 2000 LS/man trans vehicle. Looks like I'm going to have some work ahead of me.
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Verdad Gallardo The only things that I can think of needing to provide signal wires for under the dash are the guages and cruise control circuits. As best I can tell, the door locks/vats/heat and ac are all controled by the bcm. I'm thinking that it should be easy enough to use the temp/oil/fuel sending units from the v6, and modify the tach to register correctly for the v8. I'm also deleting the ABS, so that's one less thing to worry about.
Am I just over-simpifying things in my head?
