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Discussion starter · #144 ·
In your video you reference the SUV engine. What LS is the SUV engine that has better low end torque (vs. the 430hp LS3)?
There are basically three variants of the Gen IV 6.2 truck engine, but they are very similar. As mentioned there is the 2007-8 L92(all aluminum, VVT). GM added bigger injectors in 2009 for flex fuel (FF) and called it the L9H. And finally they added AFM(4 cyl mode) in 2010 and called it the L94. All great engines rated a t 403 hp with cam phasing and tune set up to move a heavy vehicle, but still rev to close to 6,000 rpm. So:

  1. 2007-8 L92 6.2 liter all aluminum, VVT
  2. 2009 L9H 6.2 liter all aluminum, VVT, FF
  3. 2010-13 L94 6.2 liter all aluminum, VVT, FF, AFM

The LS3 has several variants too, stock they are rated at 430 HP. In the Corvette there is active exhaust that adds 6 HP. GM puts bigger cams in the LS3 and sells them as crate engines, they are available in 430, 480 and 525 HP versions. The crate 480 and 525 HP engines are set up for the Corvette accessory drive while the 430 HP engine is set up for the Camaro accessory drive. The LS3's put out more torque up top. We shipped a 480 HP JKUR and 40's a few months ago to a guy in OK, it revved freely to 7,000 rpm. The 480 HP engine shined on the highway but the idle was rough and I don't think it would crawl as well as the 430 HP engine. This customer doesn't crawl with his JK but does a lot of highway driving. In a bucket list move he opened it up and GPS'd it at 140 MPH:faint: He's got more guts than me, it's the fastest JK I know of and I don't suggest anyone go that fast, I'm surprised body parts didn't fly off that JK. With the SC the customer stated he couldn't hit 100 MPH with the 40's.

In addition automatic Camaro's add VVT and AFM to the LS3 430 HP engine and it is called the L99.

We support all these engines now however the 525 HP engine needs a manual transmission to run right. Any 6.2 in a JK is awesome. But remember the 6l80 has a lot to do with it, when compared to the 4 or 5 speed Chrysler transmissions the 6l80 feels modern. If the 3.8 had a better transmission with or without as SC it would make a big difference.
 
I wanted it all, so I went with a supercharged 6.1 Hemi. with 4.10's and the 35's, it will spin them at will. I also went with Arrington heads, cam and pistons, and although it does go like a raped ape, I am thinking I need a little more gearing. I essentially have an engine that likes high rpm, but at 72 mph, im only running 2,000 rpms. Although it chugs along just fine on the highway, to gain any sort of speed at that point, its a lot happier downshifting one gear.
 
But remember the 6l80 has a lot to do with it, when compared to the 4 or 5 speed Chrysler transmissions the 6l80 feels modern. If the 3.8 had a better transmission with or without as SC it would make a big difference.
Not nearly as glamorous as an LS, but any chance of a tranny conversion for the 3.8 in foreseeable future? So far my engine has proved more reliable than the transmission.:cwm13:
 
Discussion starter · #148 ·
Not nearly as glamorous as an LS, but any chance of a tranny conversion for the 3.8 in foreseeable future? So far my engine has proved more reliable than the transmission.:cwm13:
I think your best bet is a manual 6 speed, the 3.8 is not so easy to upgrade with an automatic at this time.

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I wanted it all, so I went with a supercharged 6.1 Hemi. with 4.10's and the 35's, it will spin them at will. I also went with Arrington heads, cam and pistons, and although it does go like a raped ape, I am thinking I need a little more gearing. I essentially have an engine that likes high rpm, but at 72 mph, im only running 2,000 rpms. Although it chugs along just fine on the highway, to gain any sort of speed at that point, its a lot happier downshifting one gear.
That's interesting that you think you need more than 4.10 gears with 35s. I've got the 6.4 Hemi, with 4.10's and 35's, and I turn 2750 RPM at 80 mph. I'm pretty certain your supercharged 6.1 is making more horsepower than my NA 6.4. I wonder if you've got a different transmission, and a different top gear ratio. I've got the WA580 transmission, and gearing feels just about perfect. I routinely climb a nearby 10% grade on the interstate without downshifting from high gear. The speed limit on the interstate here is 80 mph.
 
In a bucket list move he opened it up and GPS'd it at 140 MPH:faint: He's got more guts than me, it's the fastest JK I know of and I don't suggest anyone go that fast, I'm surprised body parts didn't fly off that JK.
Wow! I'm surprised those 40" tires stayed in one piece at that speed.
 
I did 160 once, in a 2008 Challenger SRT8. And I did 165 a couple of times, on a bullet bike. Those speeds are seriously fast. If something goes wrong it is not survivable in a street vehicle that doesn't have a full racing cage, harness, etc. That guy really wanted to see how fast that JK would go, LOL.
 
Discussion starter · #153 ·
I did 160 once, in a 2008 Challenger SRT8. And I did 165 a couple of times, on a bullet bike. Those speeds are seriously fast. If something goes wrong it is not survivable in a street vehicle that doesn't have a full racing cage, harness, etc. That guy really wanted to see how fast that JK would go, LOL.
If something let go on a JK at that speed I don't think there would be any recovery, especially on a lifted vehicle. I guess that means his record may stand a little longer.
 
That's interesting that you think you need more than 4.10 gears with 35s. I've got the 6.4 Hemi, with 4.10's and 35's, and I turn 2750 RPM at 80 mph. I'm pretty certain your supercharged 6.1 is making more horsepower than my NA 6.4. I wonder if you've got a different transmission, and a different top gear ratio. I've got the WA580 transmission, and gearing feels just about perfect. I routinely climb a nearby 10% grade on the interstate without downshifting from high gear. The speed limit on the interstate here is 80 mph.
I have a 54rfe. It has plenty of go when you tell it to. Just low on rpms.
 
LC9 6L80

Here is my story so I wil TRY and keep it short. Started out with and engine fire 08 Sahara Unlimited. Had a Rubicon Express 3.5" with 5.13 gears open carriers stock axles and Nitto Trail 35's. All above came in this jeep which was owned by a gal around New Jersy area. When I say engine fire the transmission overheated, probably didn't have update to go into limp mode, boiled oil onto exhaust manifold and poof fire! Did get into interior some via engine harness and the snorkel through the soft top but not bad.

Now this is my first jeep and first CanBus vehicle so I am as green as you get! Tore vehicle down, motor, transmission, fenders, wiring, hood, doors interior front and soft top in less than 3 hours by myself! This vehicle system is very modular or component built so there isn't a ton of stuff to take apart and fairly straight forward. Chryslers part system is convoluted! Why on earth do you need 15 main harnesses for the JK model each year! To get correct harnesses you need to go off your VIN! The jeep systems were harder to learn then the motor transplant!

I almost went 5.7 Hemi even found a donor, one year old motor and tranny under 20 thousand miles but almost $7500 shipped in 2011. Then I talked to Robbie and he sold me on one of his first kits. Found two motors a 5.3 and a 6.2 both vehicles had under 20 miles. Damaged on carrier in shipping was told. Robbie wanted me to do the 6.2 but this is going to be my daily driver so went with the 5.3. The 5.3 was $4000 shipped without accessories and the 6.2 would of been an extra $1000. The biggest turnoff on the 6.2 was premium fuel and 2 was my drivetrain probably wouldn't have lived.

If I remember correctly the kit with transfer case adapter and tap shift was around $4000 since this was one of the last of his first builds he gave me a break. Plus I helped write some of his first instructions.

Paid $4300 for jeep and to my house for a total of $5500. Had $16000 to get jeep to transplant stage and in hinde site could of saved money in rebuild by not buying front end off 07 for $4000. Almost all 07 wiring and electronics don't work on any other year! So last talley with used hardtop, used soft top, new takeout 11 carpet, 12 seat covers, 4.10 re-gear, TruTrac's front and rear, Metal Cloak front lower arms, ball joints, front and rear double cardon drive shafts, Aero Force gauge and EFI Live just over $29,000!

Probably could have done it cheaper by a couple of grand but education isn't cheap! Driving impressions are 5.13's were WAY to steep! Was a drag racer but not effective for a daily that is why the 4.10's we're put in. In low range playing in snow or mud still to low. Hit rev limiter fairly easy but not like 5.13's which made low range useless! Crawling around I am happy with these gears and 35's in low range. Tap shift is handy since low range pretty much in certain situations makes your brakes worthless with all the tongue multiplication going on. The 4.56's would be too low but perfect for 37's.

Compared to my coworkers all stock 10 Sahara he fights with the wind a lot! On nice days he is happy but loaded up or windy which is pretty much most of the time up here he is not. I set cruise and never fluctuate more then 1 to 2 mph. Did I have issues yes! Did I take the body off NO! Would of it been easier to do with body off YES! Hardest part of install getting security to work. Bad scream from fire and Chrysler was no help. I am still to this day being told this CANNOT be done! I look into my garage and ther it is!

Just remember Robbie at Motech is the Holmes "Make It Right" on the jeep's. He has gone out of his way to help me on many an issue not related to the transplant even on Sundays! I would not be scared to do this transplant on any platform new or old. The chevy part was almost a non event! Plug and wire everything in as labeled and vroom it starts! My kit had some issues like too light ground wiring, Robbie had outside vendor build first harnesses and controls this in house now. Biggest little issue was a battery draw which was ECM not shutting down. This was a shutdown sequence Robbie figured out and has built into his new control board which eliminated a lot of wiring also!

In conclusion this company and this man stand by and truly care about this "Way Of Life" that I am now a part of and am looking to help build on also. It's a great community of people and Robbie is an excellent example!

Everything has plus's and minus's but this build with this motor trany combo has had way more plus's. After building and racing snowmobiles for 34 years I have been on that fine line of bid or bust TOO much and I much more enjoy the broad line the chevy has given me to a new and satisfying adventure with Jeeps!

Sorry it's not short and for some reason my IPad is not indenting paragraphs when I post stuff! Annoying!!!
 
LS/HEMI in a JK

I Love a Good V8 with a lot of HP, HEMI/LS i like them both. The LS is a lot more work to do, but a good way to go. The Hemi is getting better and better.

We do both engines and i like the LS, but it is hard to put down the Hemi, we just do not have very many problems with the Hemi and the truck VVT is a great engine.

I have a 6.2L LS in my Jeep and it runs great and it does not over heat and it runs great. I have Tap shift, Cruise, York Air compressor, Air Conditioning, Welder, shower with the LS you can have it all. It just cost a little more!

The super chargers have there place just not for me.
 
Doesn't the California motor swap law state that the vehicle must be 8 years or older in-order to preform a swap and be smog legal? I had a friend of mine just have a VVT hemi swap done at JSS and that is what he was told. So his Jeep is a 2010 so he can "legally" smog it in 2018. I'm not positive on this, I figured you guys can clarify.
The Federal Emissions Warranty, (8 Years or 80 Thousandth miles)is a federal Law and the state of California says that we can not get a emissions label until it is out of warranty. The state of California is the only state that give out a emissions labels. I think the Federal emissions warranty is bull and one Referee does not know what the other is doing. So you might get a Referee some where to pass it, if he does not know the law!
 
JSS I agree with you both Hemi and LS are good but my weapon of choice 6.2 LS3 any time of the day.

I am glad you are using Motech kit they are just awsome and Robbie is just simply the best.....




I Love a Good V8 with a lot of HP, HEMI/LS i like them both. The LS is a lot more work to do, but a good way to go. The Hemi is getting better and better.

We do both engines and i like the LS, but it is hard to put down the Hemi, we just do not have very many problems with the Hemi and the truck VVT is a great engine.

I have a 6.2L LS in my Jeep and it runs great and it does not over heat and it runs great. I have Tap shift, Cruise, York Air compressor, Air Conditioning, Welder, shower with the LS you can have it all. It just cost a little more!

The super chargers have there place just not for me.
 
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