Hello all,

I've been hitting these boards pretty hard lately trying to learn about the LS1 swap. I've searched for this as well but haven't had much luck. I notice many LS1 swaps were from efi cars to ls1's, since my 86 Z is carb, how different will the swap be, I know i'll need new fuel lines and tank and speedo, but is the wiring/fuses etc... quite a bit different? Is a carb car really hard to convert compared to the efi ones? I'm trying to decide if it is worth it or if I should look into buying an efi car. I'd like to stick with the one I have so I was curious? Also my LS1 has always used the dexcool coolant (orange junk), can I use my 86 radiator which has just been filled with the regular green coolant? I'm really excited about this swap but I want to hear how it went wiring wise from folks who had carb'd cars originally.

Thanks,
Jeremy

 

Hey man. Im in the process of swapping an LS1 myself. My car is TPI...but that doesnt really matter. Basically...the LS1, with the correct harness and computer, is pretty much stand alone. You only have to splice into a few things on your existing wiring for the motor to run, and add a relay for the fuel pump. Things like starter wire, battery power for the PCM and starter...the basics. The motor will pretty much run with only a handful of wires hooked up.

Then you have to figure out the leftover... Such as gauges, reverse light switch, etc.

Bottom line is...your swap will only differ slightly from the EFI swap. Atleast I dont think. If Im wrong...someone will jump in and correct me Good luck!

Justin

 

thanks for the info, i had a feeling the motor was pretty stand alone, so i'll be having to hook up things such as starter, pcm power, etc.. do these hook into existing wires leaving the pcm? also what about fan operation, is that through the original wires or does that take reconfiguration? with some modifying will the factory LS1 radiator and fans fit in a third gen? also am i going to have to swap all the fuse boxes over from my 98 in order to run the LS1 or will the third gen fuses and equipment work? just a few questions im pondering thanks, help so far on these boards has been terrific!

Jeremy

 

Jeremy,

Ok lets see...most the wires needed to actually run the motor come right out of the PCM. Things like the starter wire will just use your original starter "trigger" wire. Think its purple... Either way, it'll work. Now...as far as the relays go. You will need a relay for the fuel pump, and a relay for each cooling fan. The signal wire for the relays comes from the PCM. Basically a single 12V wire that will trigger the relays. Not too bad. Fan operation, assuming you have dual electric fans, will come from the PCM. You can change when the fans kick on using something like LS1edit or HPTuners.

4th gen radiator and fans will work...do a seach for the 4th gen radiator. Its not too bad. I think you have to modify the radiator a tad, and make a hole in the very bottom of the rad support in order for it to sit down low enough. No biggie...Ill be using the 4th gen rad too. It has the hook up for that coolant bypass thingy...whatever its called.

As for the fuse boxes...you dont NEED them for the say. YOu can simply add some bosch relays for the fuel pump and fans. You 3rd gen wiring will take care of your lights and all that jazz. HOWEVER...since there are already relays in those boxes, with quite a bit of wire already attached, using them to wire up your fuel pump and fans wouldnt be a bad idea. Thats what Im going to try to do instead of buying a painless fuse block or something to that effect. Shouldnt be too much trouble to use them. Make for a nice factory looking install. Good luck! Post up when you start with some pics and info!

Justin

 

thank you so much justin you have been of great help. i'll let everyone know when i start but by the looks of things it won't be til mid summer or early fall. i still gotta pull it all out of my 98. i'll make sure i keep the great info i've received from this post. if anyone else has suggestions please chime in, i'm starting to become more confident in the whole carb to ls1 swap, now i just gotta get me some fuel lines and tank.

 

Cool man glad I could help. Like I said Im no expert...but there is a TON of info on here. Also...a huge amount of info and help over at ls1tech.com. they have a conversions/hybrid section that has a ton of info as well. I just started labeling my wires and getting the plugs figured out. Its not as bad as it seems. Basically just got pin outs and wiring diagrams. Make a chart with each plug and each pin/wire. Put a check next to it to keep it, or an X next to it if its not going to be used. Once you get into it...you will realize its not that scary. Just take you time. Get as many of the parts for the 4th gen as you can. The list of parts that Im using from the 99 I got is long. Engine, Trans, driveshaft, rear, pedal assembly, fuel tank, randiator, ac condensor, coolant bottle, washer bottle and a few others odds and ends Im sure. Good luck again!.

Justin