LFX to LS7 Conversion which auto trans - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Xmetal · 06-13-2019, 06:51 AM

SO Im converting my LFX to an LS7 and the wife wants me to keep it auto so she can still drive it. Now this is not a cost issue because I know what Im up against but what I need to know is what transmission will be able to communicate with the LS7. I have the engine coming already and Im not going to buy another car thats already an 8. Just looking for some info and a trans that might be for sale that will work with this setup. Thanks in advance.

Juiced1 · 06-13-2019, 08:43 AM

Any trans will work but it'll need a separate tcm. A 6L80 or 6L90 would bolt right up. 6L80s are easy enough to find.

Xmetal · 06-13-2019, 12:00 PM

Thank you. Will the 6L80 handle 750hp? Thats my ultimate goal to get out of it. As far as a stand alone is concerned, what all will I need for it? Pardon my ignorance but this is my first build on a newer vehicle.

Chris49066SS · 06-13-2019, 01:12 PM

Quote:

Originally Posted by Xmetal

Thank you. Will the 6L80 handle 750hp? Thats my ultimate goal to get out of it. As far as a stand alone is concerned, what all will I need for it? Pardon my ignorance but this is my first build on a newer vehicle.

At 750rwhp with a 6L80 you will be on borrowed time. You'd be better off going with a built 4L80 or TH400. A built 6L90 may last a while too, but thats the element in question. Will they bolt up? Yes. Will they HOLD UP? They will until they don't. As with anything though. Look into Futral... Be prepared to beef up the suspension, axles and diff in any event, since that platform was never meant to handle that much power and the weight of the LS7. Good luck and happy modding

Xmetal · 06-13-2019, 03:12 PM

Quote:

Originally Posted by Chris49066SS

At 750rwhp with a 6L80 you will be on borrowed time. You'd be better off going with a built 4L80 or TH400. A built 6L90 may last a while too, but thats the element in question. Will they bolt up? Yes. Will they HOLD UP? They will until they don't. As with anything though. Look into Futral... Be prepared to beef up the suspension, axles and diff in any event, since that platform was never meant to handle that much power and the weight of the LS7. Good luck and happy modding

Thank you for the reply. I have every intention on beefing EVERYTHING up! I wont half ass anyone's stuff, in this case my own for that matter!! My goal is a sleeper, street/ track car.

brick59 · 06-13-2019, 05:24 PM

A mild built 4l80 will take as much or more than a full built 6l80/6l90, Im getting ready to switch over this fall, as said above you have other things to think about your diff, drive shaft and axles are not going to like that ls7 for very long.

Xmetal · 06-13-2019, 05:32 PM

Quote:

Originally Posted by brick59

A mild built 4l80 will take as much or more than a full built 6l80/6l90, Im getting ready to switch over this fall, as said above you have other things to think about your diff, drive shaft and axles are not going to like that ls7 for very long.

Isn't the 4L80 a 4 speed?

brick59 · 06-13-2019, 05:49 PM

Yes, 3 speed with a 4th gear that is your overdrive. most people that get rid of the 6l80/6l90 go with 4l80 because it is stronger and has the overdrive for highway driving.

Xmetal · 06-13-2019, 05:51 PM

What do you do as far as a correct speedometer readout when switching over to the above mentioned transmissions?

brick59 · 06-13-2019, 06:14 PM

it's all electronically controlled by tcm, there are several company that make conversion kits for the electronic part, PMC and DSX are some, if you go with a 6l80/6l90 you'll still need some kind of controller.

Chris49066SS · 06-13-2019, 06:23 PM

The TH400 is lighter, however you lose the overdrive. The TH400 is arguably the more hardcore of the 2 options. But either way, look into a transbrake, if you get that far...

Xmetal · 06-14-2019, 07:08 AM

Thank you all for the info. I already have a TH400 but want overdrive so it looks like Ill be in the market for a 4L80 pretty soon.

mikeman · 06-20-2019, 01:42 PM

I thought it wasn't possible to do a swap like this because of all the computers like the bcm in the cars. Has this changed?

Pagliaro · 07-18-2019, 02:01 AM

Interested in this build for future reasons.

06-13-2019, 06:51 AM	#1
Xmetal Drives: 2014 LS RIP Join Date: Sep 2017 Location: Maine Posts: 104	LFX to LS7 Conversion which auto trans SO Im converting my LFX to an LS7 and the wife wants me to keep it auto so she can still drive it. Now this is not a cost issue because I know what Im up against but what I need to know is what transmission will be able to communicate with the LS7. I have the engine coming already and Im not going to buy another car thats already an 8. Just looking for some info and a trans that might be for sale that will work with this setup. Thanks in advance.

06-13-2019, 05:24 PM	#6
brick59 Sucker Punch Drives: 2013 Black ZL1, 2007 Silverado LTZ Join Date: Jul 2014 Location: N.E. Ohio Posts: 275	A mild built 4l80 will take as much or more than a full built 6l80/6l90, Im getting ready to switch over this fall, as said above you have other things to think about your diff, drive shaft and axles are not going to like that ls7 for very long. __________________ 427 Dart SHP Pro LS Block, Callies Magnum Crank, Callies Ultra I Beam Rods, Diamond Pistons, AGP twin Turbos 6865, Mast heads, Cam Motion LLR cam, Morel tie bar lifters, Crower roller rockers, NW 103MM TB, ID2600 XDS, Fore Triple, DSX, E85, ARH Turbo Headers, Corsa, Jakes stage 5 4L80, Circle D, RPM Roll Bar, BMR, Carlyle Racing 15" conversion kit.

06-13-2019, 05:49 PM	#8
brick59 Sucker Punch Drives: 2013 Black ZL1, 2007 Silverado LTZ Join Date: Jul 2014 Location: N.E. Ohio Posts: 275	Yes, 3 speed with a 4th gear that is your overdrive. most people that get rid of the 6l80/6l90 go with 4l80 because it is stronger and has the overdrive for highway driving. __________________ 427 Dart SHP Pro LS Block, Callies Magnum Crank, Callies Ultra I Beam Rods, Diamond Pistons, AGP twin Turbos 6865, Mast heads, Cam Motion LLR cam, Morel tie bar lifters, Crower roller rockers, NW 103MM TB, ID2600 XDS, Fore Triple, DSX, E85, ARH Turbo Headers, Corsa, Jakes stage 5 4L80, Circle D, RPM Roll Bar, BMR, Carlyle Racing 15" conversion kit.

06-13-2019, 06:14 PM	#10
brick59 Sucker Punch Drives: 2013 Black ZL1, 2007 Silverado LTZ Join Date: Jul 2014 Location: N.E. Ohio Posts: 275	it's all electronically controlled by tcm, there are several company that make conversion kits for the electronic part, PMC and DSX are some, if you go with a 6l80/6l90 you'll still need some kind of controller. __________________ 427 Dart SHP Pro LS Block, Callies Magnum Crank, Callies Ultra I Beam Rods, Diamond Pistons, AGP twin Turbos 6865, Mast heads, Cam Motion LLR cam, Morel tie bar lifters, Crower roller rockers, NW 103MM TB, ID2600 XDS, Fore Triple, DSX, E85, ARH Turbo Headers, Corsa, Jakes stage 5 4L80, Circle D, RPM Roll Bar, BMR, Carlyle Racing 15" conversion kit.

06-13-2019, 06:23 PM	#11
Chris49066SS Drives: 2010 SS L99 Join Date: Sep 2018 Location: Missouri Posts: 1,634	The TH400 is lighter, however you lose the overdrive. The TH400 is arguably the more hardcore of the 2 options. But either way, look into a transbrake, if you get that far... __________________ Previous PB:11.079 @ 122.99mph.. New setup time: TBD The 11.079 pass: https://youtu.be/pz27Zq54t_E Build thread - www.camaro5.com/forums/showthread.php?t=555371

06-13-2019, 08:43 AM	#2
Juiced1 Account Suspended Drives: 2012 2SS CAMARO 45th Join Date: Apr 2011 Location: St. Charles, IL Posts: 18,663	Any trans will work but it'll need a separate tcm. A 6L80 or 6L90 would bolt right up. 6L80s are easy enough to find.

06-13-2019, 12:00 PM	#3
Xmetal Drives: 2014 LS RIP Join Date: Sep 2017 Location: Maine Posts: 104	Thank you. Will the 6L80 handle 750hp? Thats my ultimate goal to get out of it. As far as a stand alone is concerned, what all will I need for it? Pardon my ignorance but this is my first build on a newer vehicle.

06-13-2019, 05:51 PM	#9
Xmetal Drives: 2014 LS RIP Join Date: Sep 2017 Location: Maine Posts: 104	What do you do as far as a correct speedometer readout when switching over to the above mentioned transmissions?

06-14-2019, 07:08 AM	#12
Xmetal Drives: 2014 LS RIP Join Date: Sep 2017 Location: Maine Posts: 104	Thank you all for the info. I already have a TH400 but want overdrive so it looks like Ill be in the market for a 4L80 pretty soon.

06-20-2019, 01:42 PM	#13
mikeman Banned Drives: 2015 Camaro Join Date: Aug 2018 Location: My Garage Posts: 1,125	I thought it wasn't possible to do a swap like this because of all the computers like the bcm in the cars. Has this changed?

07-18-2019, 02:01 AM	#14
Pagliaro RIP Betsy ( Vitara ) Drives: '11 SGM 1LT/RS Join Date: Oct 2012 Location: Ottawa, Ontario Posts: 1,178	Interested in this build for future reasons. __________________ First retrofitted 2014 mylink.