increase fuel mileage

[sandsgg]

I'll have to make that a project lol, gonna be a minute till i can get access to a welder

 

[87manche]

You think it would be chapter to regear or just get new axles? I was thinking of deleting the cad anyway, so a new front was a possibility but it actually works still lol.

you can find 3.55 XJ axles for dirt cheap. 3.55's and 31's was practically factory gearing, 3.55's on 30's would be just about perfect.

If you're willing to wait around a bit you can probably find some 4.10 ones, but they'l likely be earlier axles that you'll want to upgrade, not too many 4 bangers in the later model years with the upgrade shafts and such.

So yeah, I'd swap axles, regearing is $500 an axle by the time you're done with it. someone just gave me a stock 8.25 for a 12 pack just last weekend.

 

[desertjr]

Actually 3.55s and 31s is better than factory gearing by about 100rpm..and that's assuming true 31" tires. Most run 30.5" or so. I'd guess around 100-250 rpm better pending the actual tire size.
I cruise right at 2000rpm on the highway with new 31 MUDs and 3.55. If I ever needed deeper gearing offroad then I'd go to a doubler. I will never I've up 3.55/ as long as I'm on 31s because axles are cheap & plentiful and also strong r&p :wave:

 

[sandsgg]

Gotta find someone in the area with a welder, the front axle should pretty much be a straight swap right? Just the rear axle that's the pain?

 

[kastein]

yeah the front will just bolt in. Rear you have to cut the perches off, cut the shock mounts off, weld new perches on, and possibly weld new shock mounts on too if you don't use the stock design.

Stuff you need to swap an 8.25:
spring-under (or spring-over, if you want 6" of lift in the back) leaf perches, I suggest the ones from ruffstuff
set of 4 3" U-bolts - again, ruffstuff
possibly new leaf spring plates - I made mine from 1/2" thick 6" wide steel plate, but you can buy em premade if you want
possibly a pair of shock mounts if you don't use the stock spring plates

for an 8.8:
all the same stuff from the 8.25 list except the ubolts are 3.25" instead
add a 1310 ujoint adapter flange - dana/spicer part number 2-2-1379
make sure to weld the axle tubes to the differential housing so they don't spin
you may need (depending on backspacing, rim width, and tire width) a set of wheel spacers to make the tires clear the springs/frame
some stuff I'm forgetting, I am sure

 

[sandsgg]

Thinking i may go with the 8.25 urgent decided on spring over or under yet. Probably under for now can always flip later

 

[87manche]

since you're on the cheap.

The mopar performance perches are available @ the dealer. Last set I bought was 13 bucks. You can search here in OEM tech for the part number.

 

[sandsgg]

Sweet i appreciate the help

 

[sandsgg]

$16.99 take a week to get here. They should fit the 8.25 right

 

[kastein]

since you're on the cheap.

The mopar performance perches are available @ the dealer. Last set I bought was 13 bucks. You can search here in OEM tech for the part number.

link? That's pretty damn cheap. Are they SUA/extreme travel or SOA perches?

 

[87manche]

http://www.summitracing.com/parts/dcc-4120074

your google broke? :illegalflipoff:

you can get them at any chrysler dealer.

 

[sandsgg]

Part number p4120074 16.99

 

[sandsgg]

May order from summit, cheaper there and probably faster gotta pay shipping though

 

[desertjr]

I would make my own out of 2.5" box. Make them longer & drill holes like the ruff stuff ones so you can adjust them front to rear by .5" increments. Cheap, effective and overall better because you can make then anti wrap and adjustable

 

[sandsgg]

I haven't got any experience doing that and no tools to do it with either, going to be challenging enough trying to mount them on my own lol. Gonna have to find a welder and possibly someone who's done it before, really don't like paying a shop to do my work for me

 

[ChevelleSSLS6]

I run a '96 XJ, so I'm lacking in experience with the renix jeeps, but...

HO factory header and take a dremel tool to the stock airbox. Take the stock hole (sized similar to a deck of cards) and extend it toward the fender, and back. As the airbox tapers for fender clearance, taper the hole. Yes the hole will "wrap around" the airbox. Hard to explain without pictures, and it's not as hackjob as going to town with a drill. I noticed about 1mpg more with this mod. Takes an hour of so out of an otherwise uneventful afternoon.

I have a nice (pressure bend, not crush bend) 2.5" exhaust. I know flowmasters aren't flow masters, but for the low rpms my Jeep usually sees, it works well and isn't obnoxious. I had the exhaust work before the intake, so this may- or may not- have effected the mpg.

 

[bigalpha]

Didn't see this posted, but check the lunhd website to find the testing procedure for all of your sensors. That'll tell you if anything is out of spec and needs replacement.

 

[sandsgg]

Thanks y'all, a far as the airbox goes the po already installed a k&n filter so there is no airbox anymore

 

[bigalpha]

I don't think anyone has seen any difference with a K&N.

 

[sandsgg]

Meh its already there so i figured I'd leave it