JKOwners Forum banner

1 - 20 of 391 Posts
Joined
·
749 Posts
Discussion Starter #1
We know alot of people have questions when it comes to installing a LS engine in their JK. We are opening an official tech thread for anyone running a LS engine or planning on running an LS engine.
We know there are several kit options in the marketplace and we can only speak for our own in this thread, but we will try to be helpful no matter what kit you are using. With that being said most of the info posted here will be related to the RpmExtreme swap kits for 2007 - 2011 Jeep JKs and may not apply to other kits.

We know doing a LS Swap is a big investment and there are many many options to sort out before you pull the trigger.
We will try to lay out the most common options and concerns in the next few posts and will field questions after that.

Please keep the posting to technical questions and things of that nature.

Here are some common terms to make sure everyone is on the same page.
GEN3 refers to earlier 2002-2006 engines
GEN4 refers to 2007-2013 engines
6L80e and 6L90e refer to a 6 speed automatic transmission commonly used with the GEN4 swaps
4L60e, 4l65e and 4L80e refer to a 4 speed automatic commonly used with a GEN3 swap
DBW refers to drive by wire. This would be a system where you don't have a throttle cable. This is the preferred system for an LS JK swap
TAC Module refers to the DBW module used with GEN3 engines
APP refers to the accelerator pedal (gas pedal)
:
:
:
:
:


 
Joined
·
749 Posts
Discussion Starter #2
Gen4 conversions use a 07-13 GM LS based engine. All are DBW drive by wire. They can be had in either cast iron or aluminum blocks and sizes ranging from 5.3L - 6.2L 58X

LH6 5.3L vin code “M” is an aluminum block engine producing 315HP and 338lb ft of torque.

LY5 5.3L vin code “J” is a cast iron block engine producing 320HP and 340lb ft of torque.

LMG 5.3L vin code “O” is a flex fuel version of the LY5 making the same power.

LC9 5.3L vin code “3or 7: is an aluminum block engine producing 320HP and 335b ft or torque.

L92 6.2L vin code “ “ is an aluminum block engine with VVT (variable valve timing) producing 403HP and 417lb ft of torque.
L9H 6.2L vin code “ “ is a flex fuel version of the L92 making the same power

L94 6.2L vin code “ “ is the same as a L9H but with added AFM (active fuel management)

Applications:
• 2007-2013 Cadillac Escalade (L9H for MY 2009, L94 for MY 2010-2013)
• 2009 Chevrolet Tahoe
• 2007-2013 GMC Yukon Denali/Denali XL
• 2007-2013 GMC Sierra Denali
• 2008-2009 Hummer H2
• 2009-2013 Chevrolet Silverado 1500 (as RPO code L9H)
• 2009-2013 GMC Sierra 1500 (as RPO code L9H)

LS3 6.2L was introduced as the Corvette's new base engine for the 2008 model year. It produces 430 bhp at 5900 rpm and 424 lb·ft at 4600 rpm. Look for engines from a 2010 - 2014 camaro with a manual transmission

L99 6.2L is derived from the LS3 with reduced output but adds AFM (Active Fuel Management) and VVT (variable valve timing). Look for engines from a 2010- 2014 camaro with a Auto transmission.

LS3 Crate engines:

LS3 crate engines come semi complete from oil pan to the ignition system. It also includes the EFI intake manifold assembly with injectors and throttle body, exhaust manifolds, corvette water pump & balancer and 14-inch automatic-transmission flexplate. You will still need to source an accessory drive i.e.: alternator, power steering, AC and brackets. We typically try to use a 2010 camaro accessory drive with a truck style AC compressor. You will also need to change over to a Camaro or Truck balancer and water pump. A complete parts list can be provided and will be on our website to help guide you in choosing the correct parts.

430HP 6.2L
480HP 6.2L
525HP 6.2L
 
Joined
·
749 Posts
Discussion Starter #3
With the Gen4 engine swaps we use a GM 6l80E 6 speed automatic transmission. A transfer case adapter allows us to use the stock Jeep JK 241J transfer case. The Rubicon transfer case will not work because no one that we know of makes a 32 spline input shaft for it.

The 6L80 features a generously deep first gear for an automatic, making for favorably powerful starts from a standing stop. It also features two overdrive gears. The gearing spread is a very capable 6.04, with ratios in each gear as follows: compared to your stock JK auto transmission you can see a 6L80e has a much better 1st and second gear along with 2 overdrives.
First: 4.02, JK 3.00
Second: 2.36, JK 1.67
Third: 1.53, JK 1.00
Fourth: 1.15, JK .75
Fifth: .085,
Sixth: 0.67,
Reverse: 3.06 JK 3.00

The 6L80 has a maximum RPM limit of 6500 RPM.

Maximum engine power: "555 bhp ( 414 kW )"

Maximum engine torque: "550 lb-ft ( 746 Nm )"

The 6L90 transmission is slightly longer and taller than a comparable configuration 6L80 due to it's beefier internals. GM states, ". It is a heavy-duty version of the 6L80 six-speed automatic, with a strengthened input gearset which has two additional pinion gears for six total, and a strengthened output gearset, that uses wider gears than the 6L80. The 6L90 flexibilty extends to the clutches where the 6L90 has one more clutch plate than the 6L80 in each clutch for heavy duty applications. "

The 6L90 case is about 1.4" (35mm) longer than the 6L80 case.

Our electronics and adapters will support a 6L80e or 6L90e but with a 6L90e you may need to modify the trans bracket to accommodate the extra length and driveshaft modifications are a must.

AWD/4WD Transmission-bellhousing to end of output shaft (bellhousing to end of case)
4L70: 26.875" (22.25")
6L80: 27.125" (23.3")
6L90: 28.625" (24.7")
4L80: 29" (26")

6L80 weight
Transmission weight:258mm converter: Wet: 94-96kg ( 207-211lb )
Transmission weight:300mm converter: Wet: 102-104kg ( 225-229lb )

6L90 weight
Transmission weight: w/ 300mm converter
Wet: 109kg ( 240lb ) estimated

4L60 weight
Wet: 74 - 88.5 kg (163.2 - 195.0 lb)

4L80 weight
Wet: 115 kg (254 lb)

The Engine Control Modules (ECM) that communicates with the 6L80/90 Transmission Control Module (TCM) is programmed to only recognize Gen IV LSx engines. Specifically the 58X crankshaft reluctor ring, the 4x cam shaft sprocket. The pre-2007 model year Gen III and Gen IV motors (LS2 Corvette notwithstanding) operate with a 24x crankshaft reluctor ring, a 1x camshaft sprocket are not compatible with this transmission.


Our kits offer fully functional TAP shift capabilities allowing you to fully control your shifts along with TOW HAUL mode utilizing your factory buttons. No adding a toggle switch or modifying your shifter.
Your PRNDL display will indicate the correct chosen gear 1,2,3,4,5,6 right on your factory dash. This makes it very easy to tell what gear you have selected.
This transmission is truly the unsung hero of the LS swap. Silky smooth shifts and very generous overdrives allow for less gearing and better fuel mileage. No more hunting for gears every time you come to a hill.
 
Joined
·
749 Posts
Discussion Starter #4
LS Engine Conversion Kit for 2007-2013 GEN IV GM Engines : Click here to see the kit JK-LS-GEN4-Engine-Conversion-Kit-07-11

This engine conversion kit is for 2007-2011 Jeep Wrangler JK when installing a GM LS GEN IV series engine 2007-2013 5.3 6.0 6.2 and 6L80E 6 Speed automatic transmission. The overwhelming amount of GM LS series V8 engines at great prices it makes this swap a home run.
We know it can seem daunting to try and wrap your head around so many options, we try and make it a no brainer. To get your Jeep up and running, our harness comes complete and is 100% brand new. No need to send in your old harness or modify anything and with only a few wires to splice into the existing Jeep its extremely easy to be up and running. We also incorporate a state of the art CanBus module to take care of all the data, that means you get a factory style fully integrated GM engine running in your Jeep JK with all the factory bells and whistles.
Our harness integrates the Jeep and GM side harnesses into one single harness. The engine harness routes directly to the ECU with a factory plug at the factory firewall connector. The bulk of the harness routes behind the engine and under the fuel rails which is visually appealing and allows for factory engine covers to be used. Our under dash harness incorporates the GM accelerator pedal, ALDL, GM fuses-Relays and EZ CanBus module all while plugging directly into the main harness.
The final result is a harness that features improved aesthetics and versatility, easier to install and offers premium quality and durability.

Technology:

There is a big difference in our conversion compared to others is technology. The Jeep JK is a full CanBus vehicle, what that means is everything is run by a computer speaking it's own language to all the other modules on the CanBus. GM also uses a CanBus on their GEN IV engines and vehicles, however, the GM and Jeep system don't speak the same language. What our EZ CanBus system does is take the GM CanBus and Jeep CanBus and run them through our EZCanBus module, it will then translate the language between the 2 systems and allow us to send messages between each one. We are able to take the GM tachometer signal and send it to the Jeep gauges without using an add on reluctor ring and extra wires, this saves you a lot of time on the install and this is much more reliable. We are also using the GM coolant temp signal and sending it to the Jeep gauge, again saving you time and money by not having to install an extra coolant temp sensor in the engine. Some other cool things we are able to do is have a 100% functioning PRDNL display on the dash with 1-6 gears indicated during TAP shifts. We are also able to use the factory Jeep cruise control switch to control not only the cruise control but also the GM TAP shifting with the added benefit of not having to modify your shifter or instrument cluster. The cruise light and check engine light will function as normal thanks to the EZ CanBus module. We are also able to incorporate is GM TOW-HAUL mode, by pressing you OD off button it will put the system into TOW-HAUL mode. We have many other features built into the EZ CanBus system and it is fully upgradable as we add new items.

Current features:
* 100% New harness
* EZ CanBus system
* PRNDL display with 1-6 gears in manual mode indicated on the dash
* GM TAP shifting using your factory Jeep cruise switch
* Fully functional cruise control using your factory Jeep cruise switch
* GM TOW_HAUL mode using your factory OD off button
* Factory AC control with evaporator temp monitoring
* Factory Jeep remote start functional
* Full GM Emissions compatible
* GM VVT and AFM-DOD compatible

What is in the basic kit:
* LS conversion harness
* EZ CanBus module
* Weld in motor mount plates
* Transmission mounting bracket
* Transfer case adapter 6L80E to Jeep 241J (non Rubicon)
* Transmission mount
* Transmission shifter cable bracket
* Transfer case shifter cable bracket
* Accelerator pedal bracket
* Plug n play fuel line adapter
* Jeep computer reprogramming
GM computer reprogramming
TIPM Reprograming

The basic kit comes with everything you need to get the engine into the Jeep, wired up, and running. This kit is for the guys that have experience with engine swaps and want to build their own exhaust, air intake, AC hoses, and radiator as well as all the miscellaneous parts needed.
If you're looking for a little more complete kit we offer some add on items to the base kit.

Optional or add on items:

* High flow aluminum radiator: Inlets and outlets are made to fit a LS engine and give extra room for the intake tube. This radiator also will accept the factory JK fan and condenser as a direct bolt in.
* AC hoses: Pre-made AC hoses made to fit either GM accessory or Jeep accessory drives.
* Exhaust manifolds: The same manifolds we use in house and guaranteed to fit.
* Driveshafts: We can supply you with custom driveshaft to fit with the LS conversion.
* Air intake kit: A custom made composite air intake using a K&N filter
* Jeep accessory brackets: A set of custom brackets that will allow you to reuse your 3.8 Jeep accessories.
* GM ECU Computer. We can supply a brand new E38 computer programmed to your application.
* Primary exhaust kit (engine to muffler). we can supply you with the same exact components we use to build out forward exhaust sections in the shop. It will have 2 high flow catalytic converters, o2 sensor bungs, mandrel bent pipe sections, Y style collector and stainless steel band clamps. Cutting and welding required.
* More items will be added as we build them.
 

·
Registered
Joined
·
519 Posts
One of the most detailed thread for LS conversion well done great effort.

Few questions
1. Can you post some pics of your Gen4 kit PRNDL, harness, EZ Canbus
2. With Manual JKs how do you propose PRNDL shifter and Dash Display
3. Can the GM accessories be used like Alternator, AC, and PS Pump?
4. Your wiring Harness is it genuine GM wiring harness modified or complete custom
5. What opitions are there to upgrade to your harness from other vendors already running LS engines?


GM Performance now offers complete GM genuine LS system connect and drive but do you know why they only offer the connect and drive sytem in 4L80e trans mated to LSA and LS3 etc and NOT 6L80 e or 90e
 

·
Registered
Joined
·
646 Posts
If I choose to run a 6L90 what are my T-case option?

I know you said that is designed to used a truck style water pump and crank pully. What if I want to run an electric water pump on my LS?
 

·
Registered
Joined
·
822 Posts
Is your EZ canbus module a sealed unit as far as moisture is concerned? What are the operating temperature specs for the module? Is it built to OEM standards? Where does it get mounted??
 
Joined
·
749 Posts
Discussion Starter #11
One of the most detailed thread for LS conversion well done great effort.

Few questions
1. Can you post some pics of your Gen4 kit PRNDL, harness, EZ Canbus

I will work on some pictures of the harness and such. Are you asking for a picture of the PRNDL simply on the dash? We don't use a separate PRNDL box.

2. With Manual JKs how do you propose PRNDL shifter and Dash Display

Our CAN bus module will do all the hard work and send out the correct PRNDL messages even if your Jeep was a manual. Everything will work even the BTSI shifter.

3. Can the GM accessories be used like Alternator, AC, and PS Pump?

YES. We prefer GM accessories. Another bonus is our CAN bus module takes place of the factory GM BCM and will control the GM alternator voltage so your not stuck with a set 13.6 volts. We have verified The GM truck accessories and camaro accessories will fit without modification and we offer AC hoses and adapter for them. We recommend running the GM truck AC compressor that is fixed displacement. We stay away from corvette and CTSV assessors because the AC compressor fittings are rotated to the rear and point right into the frame. We also offer a nice set of brackets if you want to reuse your factoryJK stuff, but we recommend having the alternator converted to self exciting so you don't rely on the Jeep ECU to control it.

4. Your wiring Harness is it genuine GM wiring harness modified or complete custom

Our harness is 100% brand new and is plug and play. Its has provisions for the full GM side AFM,VVT etc along with the Jeep stuff built right in. It lays out very nice and tidy and can be routed out of site for a nice clean look. The under dash harness is prewired and plugs right into our under hood harness, easy peezy.

5. What opitions are there to upgrade to your harness from other vendors already running LS engines?

We currently don't sell the harness seperate


GM Performance now offers complete GM genuine LS system connect and drive but do you know why they only offer the connect and drive sytem in 4L80e trans mated to LSA and LS3 etc and NOT 6L80 e or 90e
Im not exactly sure, I have wondered about that myself. Probably has something to do with the ECU the use and the fact that you usually need a BCM to make all the functions work on the 6L80E. We can build a standalone LS3 harness with the EZcanbus module for the hot rod guys. But for a JK a stand alone GM harness just doesn't make sense. Yes it would run the engine but the Jeep side is what runs the starter, AC,fans etc... without the CANbus working between the two it would function.

Here is how the display will look while commanding 6th gear
 
Joined
·
749 Posts
Discussion Starter #13
The importance of matching the TCM to the ECM

The importance of matching the TCM to the ECM

As a general guideline you will want to match the ECU to the TCM. The easiest way to describe it is if you have a 6L80E that came out of a 2009 silverado you would want to match it up with a 2009 engine calibration E38 ECU part number 12625455. Its far easier to program a engine computer than program a transmission computer as they are built into the valve body. We do have the capability to reflash a TCM with our bench top harness but it would require you to remove the TCM and send it to us along with the ECM.

A 2007 TCM should be matched up with a 2007 ECM #19210738
A 2008 TCM should be matched up with a 2008 ECM #12612384
A 2009 TCM should be matched up with a 2009 ECM #12625455
2010 - 2015 TCMs can be reflashed to any year between 2010 and 2013 for our application, We would match this up with a 2010-2013 ECM #12633238

A 2010 and newer transmission is the most desirable due to the fact that it will work with all the engine calibrations from 2010 and newer.


A camaro 6l80e will work with a few mods. You will need to trim the output shaft down, Add a seal and 2 pipe plugs. You should also reprogram it to a truck calibration

A 2wd 6l80E will work after you cut down the shaft and add the seals. We have a 2wd to 4wd conversion kit on our website so you don't have to hunt down seals and plugs. The kit also will come with instructions.
 
Joined
·
749 Posts
Discussion Starter #14
Manual to Auto LS swap info

Manual to Auto LS swap info

When doing a LS swap on a JK that was originally a manual you will need some extra pieces.
Despite what the internet may say the 6 speed center console is not as wide as a auto console. You can't just slap on a upper trim panel and call it a day.

Here is a list of the main parts for a 07-10 Grey console
shifter 52060162AE
Low bracket 52060490AE
cable 52060164AD
Nut 06104716AA x10
Consol base 1FG73BD5AB
Auto upper panel 1CG44XDVAB


All the ones that we have seen have the harness built into the jeep and all you have to do is plug them in and everything will work including the BTSI Brake transmission shift interlock.

You can also get the cable the runs up to the ignition lock cylinder but we usually don't do this extra step. I think it just keeps you from turning the key all the way off with the vehicle in gear.
 

·
Registered
Joined
·
1,846 Posts
I have a couple questions:
Robbie provided my lc9 5.3 (into 2010 jkur auto) from a 2012 silverado. He sent a crate trans. When the local shop installed it, there was no trans programming. They had to get the snap on guy to lend a programmer. I have tap shift. It works but I do not get engine braking. Not like a stock chev with column mounted shifter. It will drop the gear but allow rpm to rise and no compression braking.
Any ideas on the fix?

I asked motech to remove the torque management because I had done the steering wheel dance anyway. I was never bothered with the esp/bas light. My wife has started driving it more and is not 100% happy with how easy it spins the rubber when it rains.
Possible to get more nanny action? I can always use the wire cut with a switch.
Edit- possible to deactivate dash light for esp bas?

Last question for now is can you program out the side air bags?
Thanks much.
 

·
Registered
Joined
·
596 Posts
I've got a 08 jku with one tone axles and 41.5 tires looking at getting a ls but I would like to retain a manual tranny. What would I wanna look for ?
 
Joined
·
749 Posts
Discussion Starter #17
I've got a 08 jku with one tone axles and 41.5 tires looking at getting a ls but I would like to retain a manual tranny. What would I wanna look for ?
I don't really know of a good manual transmission that will bolt up, have 4wd and fit thru the stock shifter hole. Thats why we only really support the 6l80E 6 speed auto.

Its not to hard to convert from a manual JK to a LS auto combo.
 
Joined
·
749 Posts
Discussion Starter #18
I have a couple questions:
Robbie provided my lc9 5.3 (into 2010 jkur auto) from a 2012 silverado. He sent a crate trans. When the local shop installed it, there was no trans programming. They had to get the snap on guy to lend a programmer. I have tap shift. It works but I do not get engine braking. Not like a stock chev with column mounted shifter. It will drop the gear but allow rpm to rise and no compression braking.
Any ideas on the fix?

It probably has something to do with the fact your running a stock program in the transmission. When we build them in house we modify the TCM tune to match tires size and gears, then we go completely thru the tune and adjust shift points, TM, pressures etc to match the Jeep not they way GM built it for the original truck. This is a huge improvement over the "stock" TCM tune.

I asked motech to remove the torque management because I had done the steering wheel dance anyway. I was never bothered with the esp/bas light. My wife has started driving it more and is not 100% happy with how easy it spins the rubber when it rains.
Possible to get more nanny action? I can always use the wire cut with a switch.
Edit- possible to deactivate dash light for esp bas?

Your talking really about two different things. The Torque management on the engine and the Jeep's ESP system. Originally the Jeep ESP system could reduce the throttle when it saw wheel slip, now that you have a LS engine the Jeep ESP cannot reduce the throttle. There are a few ways of tackling this wheel spin issue. The easiest would be to retune the engine adding back in some torque management, reworking the timing and throttle tables to remove some of the "punch" off the line. This will make it smoother and help with wheel spin. The negative side is it will feel more "doggy" on low end.

Yes we can turn off the ESP light. You should not have any lights on the dash with a proper LS swap.

Last question for now is can you program out the side air bags?
Thanks much.

Yes we can turn them off but for liability reasons we don't mess with ABS or SIR air bags. Its pretty easy to add 2 resistors to the circuit and the system will think the airbags are still in place and the light will turn off.
Reply above
 
Joined
·
749 Posts
Discussion Starter #19
Is your EZ canbus module a sealed unit as far as moisture is concerned? What are the operating temperature specs for the module? Is it built to OEM standards? Where does it get mounted??
its approximately 4x4x1.5" with metal mounting feet at 4.5 apart.
We usually mount them under the dash.

Operating temperature is -40 to 185º F

We have a IP53 environmental rating on this particular module.
We do not recommend mounting this unit under the hood or where it would be exposed to water.

This unit is manufactured to OEM type standards, ISO 9001 and more recently ISO 14001. This is not a "home made" unit.
 
Joined
·
749 Posts
Discussion Starter #20
If I choose to run a 6L90 what are my T-case option?

I know you said that is designed to used a truck style water pump and crank pully. What if I want to run an electric water pump on my LS?
Witha 6L90E you would still use our standard adapter and a stock 241J transfer case. Or you could go with a atlas and have them build it for the 6l90e.


We run either Truck or Camaro water pumps mainly because they work on the same "belt line"

You can run a electric water pump as long as you account for the correct accessories and such. If you come up with something else that works post up and we will pass it along for others.

Be sure to address the fact that you need to run a "truck" style AC compressor. GM part #25891791 or 10S17F in the aftermarket world.
 
1 - 20 of 391 Posts
Top