Using 4l80 in Humvee with LS?

[EVANSWASTEOFMONEY]

unless i purchased the whole donor vehicle(totaled or theft recovery). I wouldn't attempt it at all. a 6.6 and 6l90 wiring and accessories have to eat up money fast if not sold as one package. I am going with a beefed up rebuilt lq9 cam heads and piston. Going for a msd box and holley carb. I will post a dyno video. A perfectly dyno tuned carb and ignition are almost as good as EFI any day. Less more wiring headaches.

 

[sail78385]

Never been a fan of carburetors off road but that’s an easy setup. Wiring isn’t too bad on the 6.6 and 6l90 except you have to take part of the transmission apart to be programmed for a stand alone controller. We will see, I really like the 6.6 L8T platform and most of the LQ engines I’m seeing around here look like rusty boat anchors. I’m planning on using 42” tires so the 6 speed would be pretty perfect for that. If I find a good clean LQ engine I’ll go that route though. Not going to make a decision till the Humvee is in my garage.

 

[Mogman]

I am SORRY,, I made a mistake, I did not realize this thread was started by a different user, I have unlocked it

 

[Mogman]

Never been a fan of carburetors off road but that’s an easy setup. Wiring isn’t too bad on the 6.6 and 6l90 except you have to take part of the transmission apart to be programmed for a stand alone controller. We will see, I really like the 6.6 L8T platform and most of the LQ engines I’m seeing around here look like rusty boat anchors. I’m planning on using 42” tires so the 6 speed would be pretty perfect for that. If I find a good clean LQ engine I’ll go that route though. Not going to make a decision till the Humvee is in my garage.

I installed a 6L90 in a HMMWV and it had stock TCM in it and a completely mechanical engine, I used a PCS external "controller" easy as pie, programming the TCM and the controller was no sweat.
Seems running the 6.6 with the 6L90 would be no problem as is, a stand alone modified harness should be all you need as long as the TCM has the original ECM to talk to it should be happy.

 

[sail78385]

Can anyone comment that has done an LS swap with the stock 4l80 transmission, is the Holley terminator Max the way to go? Where is the harness that controls all the lights on these trucks and how did you integrate to that? Full 12v conversion throughout?

 

[Mogman]

Never been a fan of carburetors off road but that’s an easy setup. Wiring isn’t too bad on the 6.6 and 6l90 except you have to take part of the transmission apart to be programmed for a stand alone controller. We will see, I really like the 6.6 L8T platform and most of the LQ engines I’m seeing around here look like rusty boat anchors. I’m planning on using 42” tires so the 6 speed would be pretty perfect for that. If I find a good clean LQ engine I’ll go that route though. Not going to make a decision till the Humvee is in my garage.

You are going to have to lift the body and or modify the suspension if you are going to run 42s

 

[Anvil Motorworks]

Never been a fan of carburetors off road but that’s an easy setup. Wiring isn’t too bad on the 6.6 and 6l90 except you have to take part of the transmission apart to be programmed for a stand alone controller. We will see, I really like the 6.6 L8T platform and most of the LQ engines I’m seeing around here look like rusty boat anchors. I’m planning on using 42” tires so the 6 speed would be pretty perfect for that. If I find a good clean LQ engine I’ll go that route though. Not going to make a decision till the Humvee is in my garage.

The 6.6 L8T is a great engine but it’ll come with with the 8 or 10 speed trans. Of course you can always adapt a 6l80 as it will bolt right up. I built engine and trans mounts for the LT engine platform as I have a built L86 with a built 8l90 adapted to the np242. I’ve spent a lot of time making sure the swap is done perfectly and I can tell you I think I have everything on point. In fact I just recently added the factory rock protection cage underneath and it clears everything. A little tight for the exhaust crossover below the engine/trans but all good. The reason I like the LT platform is the transmission options. I don’t want a 4-speed because when I’m done I plan to drive a lot of the highway and having the extra gears helps.

In short, the LT swap will inevitably be more expensive than a LS swap but that was part of the challenge, to do something someone hasn’t done, though now there are a few out there with LTs.