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So I just finished ordering everything I needed for my enginge swap. After talking to Robbie at Motech for quite a while I decided to just do a new LS3 430HP engine instead of a pull-out. I wanted to do a 480HP one but MOTECH advised it was a tougher engine to tune.

My MOTECH kit should be here in the next two weeks as well.

I will be posting pictures of the entire debacle. I dont have the space to take off the body, so I will just be removing the front.

I should have the engine in about a week and I will start the tear down. My 11 year old is so excited he can barely contain himself.

After I do the engine I will also be doing a custom cage and third row seat. The third row will have a full width drawer under it for tools. There will also be a cage around the whole compartment and reinforcement into the frame to prevent crumpling in a rear end collision.

Stay tuned.
 

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Discussion Starter #9

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Is that complete or just the engine ? This is whats on pirate now http://pacificfabrication.com/tilden-motorsports-performance-ls3-engine-package.html
If going with a MoTech LS JK install kit stay away from stand alone engine packages like the E-Rod and others. Most engine packages are designed for early vehicles and are not emissions compliant in OBD II vehicles nor will integrate into the production can network.

To maintain full functionality and emissions compliance there is a lot more to the package than you would think; in addition, we have to work within the requirements of the JK to keep everything working.

No other package I am aware of comes close to our level of OE integration. We build a complete GM Truck OS can network which includes a ECM, TCM, PMM, BCM, DLC and more. Our package supports full emissions up to 2013, OBD II enhanced data, Mode 6 data, Power modes, OE cruise control, VVT, AFM, IVT, Tow mode, can driven transmission support, tapshift.......

Unlike E-Rods or other packages we run a closed loop feedback EVAP system as GM intended. Our PMM wakes up and pets to sleep the network to maintain functionality and eliminate power drains(this was a tough one). Tapshift, bumpshift, paddles are all supported as is rpm match shifting and networked cruise control.

On the other side our electronics include our own module and wiring to support the JK functions such as PRNDL(neutral safety, reverse lights, DIC display), ESP modes, OE HVAC(air conditioning fully programmable for outlet temp, rpm and load cut off's, condenser pressure monitoring, cooling fan control, and more).

We maintain Genuine GM and Jeep parts such as engine and trans mounts, A/C lines, P/S lines, accessories. These parts are available at your local dealer so you do not need to come back to us for hard to find custom replacements.

I write this because due to the trickle down theory a small part of our business is putting back together JK's that were started with a competitor's kit, or stand alone kit, then the installer realized how difficult it is to get everything to work; so they live with a half baked swap or step up and come to us.

So save your money if you want to do a LS JK swap our way. We have been doing LS JK swaps for nearly 6 years.

We have done several LS3 480 HP swaps, and even the 525 HP swap. GM offers a E67 over the counter controller for the LS3 480 HP engine which runs great but is set up for a muscle car environment, no emission's, no can transmission support, etc. We write our own tune for the LS3 480 HP swap to make it fully functional. The 480 HP engine has an aggressive idle and needs a looser converter to run right. The LS3 and Truck 6.2's idle between 5-600 rpm which is great off road, the 480 HP engine like 750-800 rpm. It has about the same power as a 6.4 SRT Hemi but with the 6l80 it will outperform the Hemi I think. It is more temperamental than the 430 HP engine and I don't think your wife would like to drive it.

The 430 HP engines run so good and return decent economy, they idle like a 3.8 but put out almost 450 HP, it's really like two different engines.
 

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So I have a few questions.

I have stock drive train on my rubicon that's beefed up a little. Front d44 is sleeved and gusseted, rear is stock, regeared to 5:38's. Driveshafts are coast double cardan joints 1310's. Stock rok 4:1 transfercase.

What transmission do I go with the ls3 430hp?
Will the rest of my drivetrain handle the strain under the new found hp?
Would I want to regear again? Being a little low is ok with me FYI. I live In the Rockies.
 

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So I have a few questions.

I have stock drive train on my rubicon that's beefed up a little. Front d44 is sleeved and gusseted, rear is stock, regeared to 5:38's. Driveshafts are coast double cardan joints 1310's. Stock rok 4:1 transfercase.

What transmission do I go with the ls3 430hp?
Will the rest of my drivetrain handle the strain under the new found hp?
Would I want to regear again? Being a little low is ok with me FYI. I live In the Rockies.
Unless you drive like a Gorilla the stock 44's are fine. We have dozens of 6.2's with 44's and no issues. You can break a 44 in low range with a 3.8 if you apply torque and leverage wrong, especially with 37+" tires. I have a customer in Oklahoma with a 2008 JKUR LS3 480 on 40's having no problems with 44's; we did put in better axles, u-joints, C and gusseted it though. I see threads where guys with SC's blame a SC for breaking an axle, but it's more the nut behind the wheel IMHO.

1310's should be okay, however, we do recommend a 1350 rear.

The Rubi OR TC is a weak link, the front planetary will break. Swap it for a 241J and install the large input gear we supply and you won't have any problems. You not losing low range performance with this trade. The 6l80 has a 4:1 first gear and the 241J a 2.7 low ratio; the auto JKR has a 2.8:1 1st gear and a 4:1low ratio so the overall low ratio is very similar. Add the compression braking of the V8 and it will outperform a stock Rubicon.

You have to gear an LS different. First run the 6l80, it is a big advantage over other transmissions. The 6l80 is low friction, adaptive, has a manual mode and a diverse gear range from 4:1 low to .6 OD, actually it has two overdrives. This allows you to run 35's on 4:10's and 4:56's with 37's, the 6l80 makes this possible. You will still launch off the line hard and cruise below 2,000 rpm at 70 mph. The 6l80 equipped trucks are rated 2 mpg better than the 4 speeds. The goal is 1,900-2,000 rpm at 70 mph. We determined this over years and tens of thousands of miles of testing for best performance and mpg. Spinning the engine faster than this is just burning fuel. This gearing is a big advantage over the 4 and 5 speed Chrysler transmissions. If you tow, do a lot of crawling or love at high altitude and travel mountain passes go one size up on the gears.
 

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Not to derail the thread, but a local shop was warning me against the 6L80. They said the 6L80 is longer, heavier, and prone to torque converter issues than the 4L transmissions.
Could you explain, other than the awesome write-ups above, why the 6L80 is better than the 4L line?
 

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Not to derail the thread, but a local shop was warning me against the 6L80. They said the 6L80 is longer, heavier, and prone to torque converter issues than the 4L transmissions.
Could you explain, other than the awesome write-ups above, why the 6L80 is better than the 4L line?
The 6l80 is shorter than the 4l60,65,70's by about 1 1/2". It is taller which is no problem in a JK, it can be an issue in early muscle cars like Camaro's or Vettes with low ground clearance.

The 6l80 has been available in the SUV's since 2007(maybe earlier) with the 6.2 engine. Early on there were some issues with some shift flares but the architecture of the transmission is similar to the HD Allison and is very strong.

We have run 6l80's in 400, 500, 600 and 750 HP LS engines that have destroyed D60's and Atlas TC's without a single failure of a 6l80.

The 6l80 torque converter is very different than the typical TH350 converter and is less tolerant to modifications. The tolerances are very tight, we work with Edge converters to mod the converters for LS engines with big cams. If you run a truck converter designed to idle at 500 rpm with a cammed LS7 idling at 900 rpm you will have a problem.

Remember the 6l80 is an adaptive can driven transmission with it's own controller built in. No more wires running from a TCM or PCM for each solenoid, range switch, VSS, etc. The can bus has reduced the wire count to a few wires eliminating a problem with early GM 4 speed transmissions- wire chaffing, grounding out, etc.

The 6l80 pretty much became standard in the truck line in 2009 right across the board and millions and millions have been made. The failure rate is low compared to Chrysler transmissions or other similar adaptive transmissions. My new Mercedes with a 7 speed auto has been to the dealer 3 times for transmission problems and they are not exactly sure what to do.

The 6l80 has been a workhorse of a transmission and can handle over 700 ft lbs of torque in my experience, compare that to the import transmissions Chrysler uses.

Another great thing with the 6l80 is software, with readily available software the same 6l80 can take a 10 second Vette down the 1/4 mile or push your grandmas Cadillac around, it is that versatile. No more shift kits or governors or spinny things with weights that fly out.

The 6l80 is not tolerant to improper set up. Overfilling a 6l80 will cause it to run hot and burn up. I see this often and the transmission is blamed when the fluid level is 1 quart over full.

If you are going to make mechanical mods or software changes to a 6l80 make sure you know what you are doing, they respond well to tuning but with all the networking a change here will affect something over there. A common example is guys raise the rev limiter in the engine tune to 6,500 rpm for more top end, then they don't change the WOT settings in the T43 TCM, so the engine is trying to rev to 6,500 rpm and the transmission is programmed to shift at 5,700 so it short shifts and runs funny and the transmission is to blame.

Guys that grew up with muscle cars(me) who built TH350's and 400's need to rethink the way modern transmissions work, they do not respond to traditional mods so you will have problems. Work within the operational range of the transmission and the benefits are big. Better mpg, high torque rating, axle protection, great launch performance, low friction cool running, smaller trans cooler, etc.

Up till 09' GM did have several issues with shift flares, redesigned oil pump and some software updates; however, if you consider how many millions of 6l80's are out there I think you will find the failure rate very low.

We have not had one failure of a 6l80 in a swap we have done in the last 5 years so we will keep using them, in fact we stopped supporting the 4 speed autos at this point.

One concern we had with the 480 HP engine was the high idle, looser converter and the fact there is no production tune for this combination. We were conservative and wrote our own tune for the combination based on the GM performance E67 480 HP tune married to the Camaro SS 6l80 tune. It has worked well so far, we have a few 480 HP 6l80's out there with no failures.
 

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Grimscale,

I follow every V8 swap I see on three different Forums and haven't heard one guy mad that he got a 6l80! It has many improvements over the 4 series. From all I have researched it's about the trickest transmission available. You will always have naysayers on any product but I listen to the guys that design & install these systems everyday.
 

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Discussion Starter #20
18 posts so far and I haven't even done any work yet. Awesome. MOTECH's involvement is why I went with them, you can tell how much they stand behind the product, and it hasn't even shipped yet!
 
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