Power loss from 35's? & pwr mods - Page 4 - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > JK Wrangler Technical Forum > Power loss from 35's? & pwr mods

Ruffstuff Axle Simple Swap Kit!Even Better Heim Pricing! From RuffstuffToxic Brakes - 3000 PSI Braided Stainless Steel Brake Line

Reply
Unread 02-22-2011, 03:10 PM   #46
KevinBreeden
Registered User
2008 JK Wrangler 
 
Join Date: Dec 2009
Location: Virginia
Posts: 74
What is a ball park price for gears and the install. I too just put on 35s and have driven around a couple days and I can't deal with it, it is a dog on the highway..

__________________
2008 Wrangler Rubicon Unlimited - 2.5inch Teraflex lift shocks and springs - Teraflex 9550 shocks - 1inch performance accessories BL - AEV Pintler Argent 17/8.5 - Cooper Discoverer STT 35/12.50/17
KevinBreeden is offline   Reply With Quote
Unread 02-22-2011, 04:49 PM   #47
RockyClymer
RedRock4Wheeler
 
RockyClymer's Avatar
2008 JK Wrangler 
 
Join Date: Apr 2008
Location: Colorado
Posts: 4,409
$1000 to $1500 would be a starting range.
__________________
08 JK 23S - Colorado Jeep Club No. 204
Too much to list - see my profile for details on build
NRA Life member
"It takes a special kind of stupid to believe criminals will follow gun laws."
I do not consider myself a smartass. I point out the obvious, search for the truth, and speak fluent sarcasm. I am, by experience, an accomplished curmudgeon.
RockyClymer is offline   Reply With Quote
Unread 07-16-2012, 05:03 PM   #48
flashpoint83
Registered User
2012 JK Wrangler 
 
Join Date: Mar 2010
Location: , Washington
Posts: 125
So with a gear change your axle warranty would be voided? My dealer gave me a vehicle lift form that stated any lift up to 4" would not void the warranty. But I dont want to go too big if I cant have a gear change!
__________________
2012 Wrangler Sport
flashpoint83 is offline   Reply With Quote
Unread 07-16-2012, 05:21 PM   #49
SubAtomicGenius
Sarcastic Fantastic
 
SubAtomicGenius's Avatar
2011 JK Wrangler 
 
Join Date: Jun 2011
Posts: 3,005
^^^ My understanding is warranty is only void if they can prove the mods did the damage. Seriously, what is going to happen to an axle that involves a "good" gear swap? Bending the axle tubes, snapping an axle shaft, bending the axle "C"s - ie. a Wrangler under hard use - I can't see any of these being covered by warranty anyways (???). And for obvious reasons - if you do have ring and pinion and/or bearing damage down the road - the dealer isn't going to get you a new set of 4.56's or 4.88's when they don't stock them. Now a "sloppy" gear swap - one where you have gear/pinion, bearing cap, or housing damage due to a bad install is another story... a dealer can't be responsible if your gear swap caused the damage. However, with a proper shop install (or personal install if you have the knowhow/tools) I don't think you'll have any problems with a voiding warranty (but that's just my opinion!!!).

As far as lifts voiding warranty - that is dependant on the dealer themselves. My dealer told me any size tire over stock size with a lift over 2" voids warranty. Too late after I already bought it - I love my Jeep, but this will be the last vehicle I buy from them! I might be in "a different boat" than you, but I lifted and slapped 35"s on her anyways. Forget the warranty, if it comes to it I'll just have to kick up a fuss I guess (knock on wood!)...
SubAtomicGenius is offline   Reply With Quote
Unread 09-23-2012, 10:54 AM   #50
deerassassin22
Registered User
2011 JK Wrangler 
 
Join Date: Apr 2010
Location: Phenix City, AL, Alabama
Posts: 658
What is the biggest you can go in a 2011 JK Unlimited Rubi I'm thought i read someplace the Super Dana 44 will only take up to 5.13's
__________________
Cobra 29 CB, 4ft Firestick Antenna, Skid Row Evap Skid, Rockhard Engine Skid, Rockhard Tranny Skid, Mesh Grill Mod, Mastercraft Grab Handles, Front and Rear ARB Diff Covers, Smittybilt Rock Rails, KC 130Watt Long Range Lights, Delta Light Mounts, TorqFlo tranny cooler, Hood Louvers, Drake Hood Pins, AEV Snorkel, Smittybilt 10,000 Winch, Rockhard Shorty Bumper with KC 100watt Slim Light Driving Lights, JKS ACOS Front System, Breather Extensions.
deerassassin22 is offline   Reply With Quote
Unread 09-24-2012, 08:40 AM   #51
HappyTrails
Registered Voter w/ID
 
HappyTrails's Avatar
2008 JK Wrangler 
 
Join Date: Nov 2008
Location: West Georgia
Posts: 1,725
I have a 08 2-dr Rubi (D44's f&r), am running 5.38's. I believe 5.89's are the lowest that will fit in stock D44's (if you can find 5.89's).
__________________
2008 2-dr Rubicon, auto,
RK 2.5" Max Travel lift, Fox 2.0 shocks, 37" Nittos, 5.38's, River Raider skids, Warn VR8000-S.
RIPP Gen 2 Stg 2 Supercharger.
Re-inventing the circle and straight line.
HappyTrails is offline   Reply With Quote
Unread 05-02-2013, 05:26 PM   #52
dualtjs
Registered User
2011 JK Wrangler 
 
Join Date: Mar 2008
Location: Atlanta
Posts: 1,281
So what these charts are telling us is that the creator of the chart believes that 99.9% of all JK's, with 3.8L motors, were improperly geared when built (I'll leave room for 0.1% to be "properly" geared due to customer orders)? I'm having trouble believing that.
dualtjs is offline   Reply With Quote
Unread 05-02-2013, 06:38 PM   #53
Prot
Web Wheeler
 
Prot's Avatar
2014 JK Wrangler 
 
Join Date: Feb 2007
Location: Lafayette, LA
Posts: 7,350
Quote:
Originally Posted by dualtjs
So what these charts are telling us is that the creator of the chart believes that 99.9% of all JK's, with 3.8L motors, were improperly geared when built (I'll leave room for 0.1% to be "properly" geared due to customer orders)? I'm having trouble believing that.
Drive a 3.8L with an automatic and you will believe.
__________________
2014 Copperhead Pearl Unlimited Sahara in progress
Prot is offline   Reply With Quote
Unread 05-02-2013, 07:41 PM   #54
dualtjs
Registered User
2011 JK Wrangler 
 
Join Date: Mar 2008
Location: Atlanta
Posts: 1,281
Quote:
Originally Posted by Prot View Post
Drive a 3.8L with an automatic and you will believe.
I have a 2011 Unlimited with automatic. Would I say that it's ideal? No, but I also don't have "minimal use of OD", even with 33" tires (that don't even put it into the yellow band). From my experience with my JK and the ones that I test drove, 4.10 gears with 33" tires should have a JK almost to the bottom end of the "acceptable" range (prob not in it, but 1 notch outside). 4.56 would probably be the best choice, for auto tranny and 33's (4.88 with 35's).

In addition, according to the charts the 3.21 geared manual tranny JK's should have 28" tires (technically 27.5, but most "28's" are that size) to barely make it into the acceptable range. I didn't drive any manual tranny JK's but I find it hard to believe that 28's with 3.21 gearing is "ideal".

I kind of over stated my point, because stock manual Rubi's and Sahara's would be in the acceptable range, but the point remains that these charts are a little biased towards higher gear number.
dualtjs is offline   Reply With Quote
Unread 05-02-2013, 07:45 PM   #55
plac
Registered User
2012 JK Wrangler 
 
Join Date: May 2006
Location: CA
Posts: 1,425
nothing new at these forums. the guys are all modders and want to mod. my 3.21 gearing in my manual 3.8L was perfect for me. and probably 80% of the rest of the world that isn't on these forums.
__________________
2013 VW GTI
plac is offline   Reply With Quote
Unread 05-02-2013, 09:22 PM   #56
dualtjs
Registered User
2011 JK Wrangler 
 
Join Date: Mar 2008
Location: Atlanta
Posts: 1,281
Quote:
Originally Posted by fernjack View Post
Most guys on here will tell you to save your cash and use it for gears .....the intake & exhaust thing just doesn't make ponies on this engine . Probably would need a cam and a retune to be able to use the intake & exhaust . Are you auto or 6spd. ?
I'm not looking to run 35's, but I have the infamous auto tranny, so I've been looking into the same question as the OP. After a lot of research, I've come to the conclusion that this is the best plan (i.e., save the cash for intake & exhaust and put it into gears). Even if you loss an MPG or two, because you are running higher RPM (although, it shouldn't), 2 MPG means 10% more gas consumed. At $4 per gallon, that means $2,000 in gas over 100K miles (assuming 18MPG average). $6,000 supercharger or $2,000 in gas.
dualtjs is offline   Reply With Quote
Unread 05-02-2013, 09:54 PM   #57
RIPNBST
Registered User
2004 WJ 
 
Join Date: Mar 2013
Location: Broken Arrow, Oklahoma
Posts: 266
Quote:
Originally Posted by dualtjs View Post

I'm not looking to run 35's, but I have the infamous auto tranny, so I've been looking into the same question as the OP. After a lot of research, I've come to the conclusion that this is the best plan (i.e., save the cash for intake & exhaust and put it into gears). Even if you loss an MPG or two, because you are running higher RPM (although, it shouldn't), 2 MPG means 10% more gas consumed. At $4 per gallon, that means $2,000 in gas over 100K miles (assuming 18MPG average). $6,000 supercharger or $2,000 in gas.
Take your logical approach and GTFO.
RIPNBST is offline   Reply With Quote
Unread 05-03-2013, 06:41 AM   #58
tyvanwie
Registered User
1998 TJ Wrangler 
 
Join Date: Sep 2012
Location: Boone, North Carolina
Posts: 9,523
Quote:
Originally Posted by Prot

Drive a 3.8L with an automatic and you will believe.
I can vouch for this. My 08 was horrendous.

Sent from my iForum using JeepPhone
__________________
[SIZE="4"][B][COLOR="Red"][URL="http://www.jeepforum.com/forum/f22/tys-tj-1475530/#post14926343"]MY BUILD THREAD[/URL][/COLOR][/B][/SIZE]
[SIZE="4"][B][URL="http://www.jeepforum.com/forum/f374/tyvanwies-log-transformation-1489190/"]MY FITNESS LOG/TRANSFORMATION[/URL][/B][/SIZE]
[SIZE="4"][B][URL="http://www.jeepforum.com/forum/f127/jk-tj-parts-1525039/"]JK AND TJ PARTS FOR SALE[/URL][/B][/SIZE]

I'm pretty sure I know what I'm talking about. I think...
tyvanwie is online now   Reply With Quote
Unread 05-03-2013, 02:25 PM   #59
JTPhoto
Web Wheeler
 
JTPhoto's Avatar
2008 JK Wrangler 
 
Join Date: Apr 2008
Location: South Gillies Ontario
Posts: 1,822
Quote:
Originally Posted by dualtjs

I have a 2011 Unlimited with automatic. Would I say that it's ideal? No, but I also don't have "minimal use of OD", even with 33" tires (that don't even put it into the yellow band). From my experience with my JK and the ones that I test drove, 4.10 gears with 33" tires should have a JK almost to the bottom end of the "acceptable" range (prob not in it, but 1 notch outside). 4.56 would probably be the best choice, for auto tranny and 33's (4.88 with 35's).

In addition, according to the charts the 3.21 geared manual tranny JK's should have 28" tires (technically 27.5, but most "28's" are that size) to barely make it into the acceptable range. I didn't drive any manual tranny JK's but I find it hard to believe that 28's with 3.21 gearing is "ideal".

I kind of over stated my point, because stock manual Rubi's and Sahara's would be in the acceptable range, but the point remains that these charts are a little biased towards higher gear number.
So here's the long term deal. 08 unlimited 3.73 gears and heavy 35" tires (86lb ea). I've had it since new it is a daily driver and traveller, spends 90% of the time on the highway.
Programmed with a Superchips and I run OD OFF ( equivalent to 5.13 gears) all the time at an average 17mpg.

When originally designed the Wrangler package was sufficient with stock wheels and an auto with 3.73 stock 32" tires and was capable of 23 mpg, however, as soon as you step up even one size in tire the OD, in my opinion, is useless. It constantly kicks on and off which stresses the drivetrain and is harder on fuel. The 3.8's sweet spot is 2100-2300rpm. This is where it get the best fuel economy.

My take is there is absolutely no issue with power with the 3.8 engine itself at lower elevations. The transmission gearing is two ratios too high and that is the issue. Look at the RpM charts and compare rpms vs gears. The final gearing in an 07-11 would have to be 4.56 just to be equivalent to a 12-13 with 3.73. Older automatics did not come factory with 3.21, only the manual trans did with 28" tires.
__________________
^^Jeff^^
2008 Black and Khaki Sahara Unlimited. Auto, Tow pkg, Dual Tops, MyGig, Trax-Lok rear diff. 3.5" Rock Krawler fr springs, rear TeraFlex 2.5 BB, 35x12.50x17 Pitbull Rockers on Blackrock Viper Alloys, Flex-o-lite trans cooler, Mr Grille billet grille inserts, AEV Prem Bumper ETC.. AND a Locked and Lifted Honda Foreman for when the trails get real tight
JTPhoto is offline   Reply With Quote
Unread 05-03-2013, 02:58 PM   #60
JIMBOX
Web Wheeler
2008 JK Wrangler 
 
Join Date: Oct 2008
Location: NORCAL/NORNV
Posts: 4,654
The above data is kinda true, but

The JKU/w auto and stock tires, using 4,10 gears is a complete loss any time there are overpasses/hills and headwinds on a freeway--

4.56 gears would be a waste of money, even for 33" tires, the O/D function of the 42rle auto would still be sick puppy

Any regearing for the 07-11 JKU should be minimum 4.88 and probably 5.13 on the off-chance of going to larger tires later-33/34/35

Any of those changes from 4.88/5.13/5.38 will increase the gas mileage, improve both the throttle response and torque applications to the ground-

5.38s are the "top cat" move, but thats another story-

JIMBO
__________________
Yellow Jeep No. 683
http://i294.photobucket.com/albums/m...10-snow027.jpg
--YA GOTTA HAVE CLASS--
JIMBOX is online now   Reply With Quote
Reply

Tags
3.73 gears , 35" tires , JK Wrangler , power loss , stock gears , wrangler
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.