Close

Page 3 of 4 FirstFirst 1234 LastLast
Results 21 to 30 of 31
  1. #21
    Been Around the Block scrhino's Avatar
    Join Date
    Oct 2012
    Location
    Auburn, AL
    Posts
    285

    Motech swap questions with Gen IV 480hp LS3 crate engine

    Quote Originally Posted by BigPrince View Post
    I'm running 60 front, Sterling rear, and 41.5" Pitbulls. For the crawling we do, I would like to run the numbers on a 4 speed if the computer doesn't have a problem with it(?).

    Eddie has a different primary use case being in Nevada. You're from Auburn - ever go to Chocco? The guys I've seen do Boatramp have been ultra low geared going slow and I've seen bouncers throw big HP at it and not make it.

    Motech - thanks for the overview. Sounds like both of y'all agree 5.38s would be ok, if a little torquey, with 40-42s. I may just want to swap out or regear(if possible) the Atlas. Figured I would need to change the input, maybe just do that and see how much I like/hate it and go from there when the time for the conversion comes.

    Thanks!
    Quote Originally Posted by highoctane View Post
    I live at nearly 6k feet in northern AZ, and frequently drive long, steep mountain grades on I17 in AZ, so I'll for sure be staying with the 5.38 gears in my Dynatrac axles. By swapping in the 241J with the 2.72:1 low range I'll be just fine offroad. If I ever break the xfer case or adapter I'll go to an Atlas II.


    Sent from my iPhone using WAYALIFE mobile app
    Based on what motech is saying I may switch to the 3.0 Atlas or just stick with my 2.72. Hard to know exactly what is the best route to take.

    Never been to Choco but been to windrock several times.
    Liston

    2010 JKUR LS3 6.2 430 HP / 6L80
    Instagram: black_rhino_jk

    EVO suspension and bumpers. Warn Powerplant.
    Dynatrac axles and brakes.
    Rockhard 4x4 sportcage.
    37x12.50x17 Trail Grapplers on Atx Slabs.

  2. #22
    Nothing but a Thing RMC2's Avatar
    Join Date
    Jul 2013
    Location
    GA
    Posts
    1,047
    You guys make me jealous. Good luck with the swap. If I could only win the lottery. Gotta buy a house instead.

    Liston, you sending your jeep to ORE or doing it at home for the axle swap?
    Matt

    Do the speed bumps at the mall count as crawlin?

    N.S.D.Q.!

    13 JKUR - white, 09 JKUR - white (sold), stock 85 CJ7 - red
    6 other 4x4 trucks (but only have 1 now).

  3. #23
    Been Around the Block Basscat's Avatar
    Join Date
    Sep 2016
    Location
    Durango, CO
    Posts
    256
    Quote Originally Posted by BigPrince View Post
    With the proposed engine/trans in this thread (430/495 6l80), what gearing does Motech recommend for Atlas TC and axles? I have 5.38 in my axles and a 4.3 Atlas II currently in my 2014 3.6l. Wondering if it would be worthwhile sending to AA to redo the current Atlas or buy new. Anyone run a 4speed? I also have a PSC pump/hydro assist already and appreciate the early info.
    You'll want to change the gearing in your Atlas to 3.8 or 3.0. If cradling is what you do most go 3.8. If driving fast off road do 3.0.


    Sent from my iPad using WAYALIFE mobile app

  4. #24
    Been Around the Block
    Join Date
    May 2014
    Location
    san jose
    Posts
    271
    Gearing in the TC should be checked in relationship to the trans gearing , axle gears and tire size...I played for hours using Grimmjeeper gearing calculator before I decided on 5.38's and a 3.8 Atlas.

    Your result will will be whats best you.

  5. #25
    Advertiser
    Join Date
    May 2013
    Location
    LAS VEFAS
    Posts
    58

  6. #26
    Been Around the Block
    Join Date
    May 2014
    Location
    san jose
    Posts
    271
    The Alt bracket pulleys....JK's or Chevy's or ??

  7. #27
    Advertiser
    Join Date
    May 2013
    Location
    LAS VEFAS
    Posts
    58
    Quote Originally Posted by 2011jk View Post
    The Alt bracket pulleys....JK's or Chevy's or ??
    We support both the GM and JK accessories, I feel the stock JK accessories with our billet brackets are the best choice.

    With the MoTech billet brackets the accessories go back where they were using the stock hoses, lines and electrical connectors; in addition, there are no interferences with the steering gear, frame rail or UCA like there can be with the GM drive.

  8. #28
    Been Around the Block
    Join Date
    May 2014
    Location
    san jose
    Posts
    271
    Yes but do you use the JK stationary and groved pulleys or the LS truck ones for the Alt bracket when using a JK Alt?

  9. #29
    Advertiser
    Join Date
    May 2013
    Location
    LAS VEFAS
    Posts
    58
    Quote Originally Posted by 2011jk View Post
    Yes but do you use the JK stationary and groved pulleys or the LS truck ones for the Alt bracket when using a JK Alt?
    One smooth and one grooved 75mm.

    Dayco 89115
    Dayco 89144

    The smooth pulley is the same idler pulley the 3.8 JK runs. If you had a belt that was a little long you could substitute a 90mm pulley.

  10. #30
    Been Around the Block Basscat's Avatar
    Join Date
    Sep 2016
    Location
    Durango, CO
    Posts
    256
    Quote Originally Posted by MOTECH View Post
    TBH I like the LS3 430, I prefer the drivability over the 480 HP engine. We find the LS3 430 HP engine has about 450 HP at the crank and will outperform a stock 6.4 Hemi when running a 6l80 transmission.

    The 6l80 is a strong transmission and it is unlikely you will break it even with a supercharged LS, we have run them in 700 HP engines with no problem. Our 6l80-241J TC adapter is good to 500 HP, we have many running behind the 495 engine. The Atlas 2 is a good choice if you need it - 2WD low and front wheel drive. If you don't need an A2 the 241J works great. I do not recommend(and neither does Advance) the Atlas 4 or the 241OR TC, they don't deal well with the torque. We also support the 6l90 transmission but realistically I would not run a 6l90
    unless I already had one.

    Stock 44 axles can hold up well with a 6.2 engine with tires under 37", if your running larger than 37's you want to beef up your stock axles or go with some 60's or... I like the D80 rear and D60 front combination. I have 80,000 miles on my stock 44's with a 6.2 with no issues because I drive conservative and that is what matters, you can break axles with a 3.8 in low range if you drive like a gorilla. But for the most part if running a 6.2 with 40's beef up the axles, if running 35" or smaller tires you can get away with the stock axles.

    We have recommended gearing and you shouldn't gear an LS like a Hemi or V6. The diverse gearing of the 6l80 means you can launch hard with a 4:1 first gear and cruise at low rpm with a 2cd OD of .66. This means you can run 37's on 4:10's and still get reasonable performance. For general driving(both off road and highway) we like to shoot for a 2,000 rpm cruise speed at 70 mph. This gives you good off road performance with a 3:1 TC and good economy on the highway. So for general guidelines:

    35's - 4:10's
    37's - 4:56's
    40's - 5:13's.

    Now the LS is tolerant to gearing due to the 6l80 transmission and lots of torque. If towing or you live in the mountains of Colorado go up one gear size, so 4:88's with 37's instead of 4:56's. If you do mostly highway driving go down one gear size, so 4:10's with 37's instead of 4:56's. Do not go too low on the TC ratio unless you have a need. A 3.8, 4 or 5:1 TC is great on a rock but sucks on trails. With a 4:1 TC your screaming the engine in 6th gear to go 15 mph down a trail and with the torque of the LS you don't need to do that.
    Really good advice right there!

    I'm running PR80 rear / XD60 front, 40" tires, 5.38s, 3.8 Atlas. Cruises at 70mph / 2,100 rpm. Runs very strong in the Colorado mountains (live in Durango). Engine is 6.2 LS3 (450hp) with 6L80. Excellent combo in all conditions both on and off road. Very low first gear when technical crawling but strings out well with 6L80.


    Sent from my iPad using WAYALIFE mobile app



Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •