I may have jumped the gun, but i picked up a LY6 with 823 aluminum heads last night for what i think was a good deal. I was prepared to tackle the added complexity of the Gen IV swap, but reading more on here doesn't look like anyone has mated a T56 to an LY6? wondering if it is even possible? car is a 91 manual, and i want to keep it a manual.
Any insight would be appreciated

 

Yeah, why not?
You're going to need a flywheel, pilot bearing, etc., but any LS-series T56 will bolt up just fine.

EDIT: How much did you pick that LY6 up for?

 

i think i was panicking when i started this thread, but i know it will bolt up with proper pieces. I realized QwkTrip has a T56 and an LS7 but he is using a Holley ECM, not sure if i can get away with the stock harness and ecm? it doesnt look like there was ever a manual trans behind a LY6 in stock format. Not sure if this will matter, but to clarify my original post: what if anything needs to be done to wiring or programming to use stock ECM and a T56?

 

I'm no expert, but I'm pretty sure you would just turn off any transmission/ traction control features in the PCM.

With the manual LS cars, the PCM never "knows" what gear the transmission is in, which blows my mind. This is part of the reason why GM never had variable-valve-timing or displacement-on-demand (AFM) available on any manual transmission vehicles.
Those features must need some kind of feedback from the transmission.

Hell, you could probably just bolt in the T56 and run it, but you'd get a bunch of P07XX codes for the missing auto transmission.

 

Okay, that actually makes sense. Hopefully I can just disable TCS or change some parameters, if it throws a code hopefully it is still happy. Thanks for the confidence lol
BTW I read up on your build and I like the budget stuff you have done. Has given me some inspiration to do alot of the swap stuff myself instead of buying new everything. No fun in that anyways haha

 

The LS T56 or a Magnum F will bolt up and work with no "special" parts, just all the same ones you would need for the T56 normally.

The autos and manuals have different tunes in the ECM. You should be able to get away with just shutting the codes off in the configuration, but the better way is to just upload a complete tune from a manual car. The Holley doesn't know or care about the manual transmission, it is not much different than a regular engine swap. Basically it is all the same except the Holley only uses one O2 sensor instead of two. You can make the VSS report speed to the Holley and get it to work the reverse lockout solenoid if you so chose too.

 

Thanks for the info Scooter. Looks like I am good to continue with this swap! Will start a build thread once I really start on this thing this winter.

 

You can download HP Tuners software for free and then open a tune that somebody saved to a forum somewhere. That would give you a chance to look at the software before buying anything. Might settle a lot of the worry/uncertainty in your mind.

You only pay for the equipment and ability to access a real engine ECM.

 

The physical connection of the engine and transmission is no issue at all.

A pilot bearing/ bushing is required with the rest of the clutch gear.

Electronically speaking... an PCM for an engine with matching crank and cam reluctors, as well as a 6-speed from a camaro/ corvette would be fine.
In the aftermarket, you have more options with software or hardware.

 

I’m doing an LC9 to T56. No issues with the mechanical hookup. I’m struggling with getting the ECM to control the reverse lock-out. “Swapping in a manual tune” is the most commonly suggested solution, but I can’t find a compatible OS for a manual car. There are workarounds, however, for the reverse lock-out if it becomes necessary.

 

FWIW, I don't have anything connected to the reverse lock out (literally, we took that out of the harness, lock out is acting as a plug in the side of the trans), you just have to push the shifter over harder. I did it out of a little ignorance and the fact that I know I'll never be able to get the shifter into reverse unless I mean to.

Physically mating the engine and trans should be one of easier things to do, just get the appropriate parts as mentioned above. If you can swing a Magnum F, absolutely do it. They shift nicer than the T56 (which isn't bad, but progress happens) and will hold more torque, that way if you add more down the road, it's one less thing to worry about. A manual tune would be your best option for a smoother transition, as you're going to have to go into the tune to disable some codes, make it less likely for forget some setting since there will be a bunch of things to disable related to the trans. A decent shop would be able to do all that for you easily enough either way though.

Oh, don't forget to properly measure clearances when you put the clutch/throw out bearing in, I goofed on that when I last replaced my clutch and have a clutch that barely disengages now.

 

Thanks for the advice! wouldn't be the end of the world for me not having reverse lockout so good to know that is an option.
Is there anywhere I can get a LY6 manual trans tune file? I will be getting a buddy (extensive tuning experience) to help me tune to start as well. I tried searching the forums, but haven't found the specific file I need.