bolt ons for 4.0

[comanche1989]

Hey, does anyone know of some cheap bolt-ons or build threads with good bolt-ons that can give the 4.0 a lil more kick? Help a speed addict out! :banana:

[Pete M]

gears, gears and more gears. upgrading the ratio in the axles (usually by swapping in whole junkyard axles) will always give the best bang for the buck. :thumbsup:

[cruiser54]

Pete's right. Is your truck stick or auto?

 

If you're dying to do bolt-on engine mods I can help you out a bit.

[hick92]

Ahh bad idea jeep was never intended to be a racecar

[Harley]

Ahh bad idea jeep was never intended to be a racecar

 

Mine will be when its done. It'll be the GTO of Jeep. a wolf in sheep's clothing!

[Dadinator]

Hey, does anyone know of some cheap bolt-ons or build threads with good bolt-ons that can give the 4.0 a lil more kick? Help a speed addict out! :banana:

 

Gears, header and good free flow exhaust system. Cold air intake. Cam and roller rockers larger injectors, larger throttle body. N2O or blower if you're serious.

 

Not sure how much the factory computer can take.

[comanche1989]

Pete's right. Is your truck stick or auto?

 

If you're dying to do bolt-on engine mods I can help you out a bit.

 

My Truck is the BA-10 5 speed. Some help would be much appreciated. :wrench:

[Pete M]

step one is to get rid of those crappy 3.07 gears. 4.0/auto XJ/MJs will have 3.55s behind them and are everywhere. :thumbsup:

 

what size tires are you running?

[jakeWI]

Bored Throttle Body, 99+ intake manifold, injectors, cold air intake, new exhaust manifold, gears...

[HKB3]

A LS_ swap will probably give you the most bang for your buck.

 

 

You can find 5.3L's (300+h.p.)with a 4L60e and harness/ecu for around $1500

[cruiser54]

step one is to get rid of those crappy 3.07 gears. 4.0/auto XJ/MJs will have 3.55s behind them and are everywhere. :thumbsup:

 

what size tires are you running?

 

 

Gears/axles from an auto trans MJ would be a good step to take. Better yet, some 4.10s out of a 4 cylinder MJ. Bored TB from www.strokedjeep.com, have a headpipe made that eliminates the "crush" in the stock one, High altitude CPS, free flowing exhaust system.

[skidoo_j]

step one is to get rid of those crappy 3.07 gears. 4.0/auto XJ/MJs will have 3.55s behind them and are everywhere. :thumbsup:

 

what size tires are you running?

 

 

Gears/axles from an auto trans MJ would be a good step to take. Better yet, some 4.10s out of a 4 cylinder MJ. Bored TB from http://www.strokedjeep.com, have a headpipe made that eliminates the "crush" in the stock one, High altitude CPS, free flowing exhaust system.

 

Do you have one of the bored TB? Did it come with a new butterfly? Did you have to modify the intake opening? Gaskets any different? Noticeable difference at what rpm's, mpg, more acceleration etc. ?

[Jeep Driver]

A LS_ swap will probably give you the most bang for your buck.

 

 

You can find 5.3L's (300+h.p.)with a 4L60e and harness/ecu for around $1500

 

 

 

Very nice.

 

2W or 4W?

[HKB3]

Not mine, it is 4wd. IIRC there is a build thread on http://www.LS1tech.com on it, btw it is a XJ.

Another build with a LS2 http://www.naxja.org/forum/showthread.php?t=1033464

[COFFMAN]

Not mine, it is 4wd. IIRC there is a build thread on http://www.LS1tech.com on it, btw it is a XJ.

Another build with a LS2 http://www.naxja.org/forum/showthread.php?t=1033464

Hi HKB3 do you have user name for the red xj with LS1 conversion

Thanks if can help

[cruiser54]

step one is to get rid of those crappy 3.07 gears. 4.0/auto XJ/MJs will have 3.55s behind them and are everywhere. :thumbsup:

 

what size tires are you running?

 

 

Gears/axles from an auto trans MJ would be a good step to take. Better yet, some 4.10s out of a 4 cylinder MJ. Bored TB from http://www.strokedjeep.com, have a headpipe made that eliminates the "crush" in the stock one, High altitude CPS, free flowing exhaust system.

 

Do you have one of the bored TB? Did it come with a new butterfly? Did you have to modify the intake opening? Gaskets any different? Noticeable difference at what rpm's, mpg, more acceleration etc. ?

 

Bolts right on with a new gasket. Has big butterfly. Adjust your TPS and go. Spunkier acceleration. No loss of MPG after you play with it alot on the first tank full of gas. Manifold bore is already 60mm. Interesting, huh?

[comanche1989]

so, I'm a highschool student, witha minimum wage job.... i need bang for my buck. i have a budget of about 500$ :oops:

[Pete M]

plenty for a $150 junkyard axle. :yes: try car-part.com but be sure to search for XJs and MJs and various years of them. newer is better, but any will do if they are in decent shape. any XJ/MJ rear axle will go in with minimal effort. and other Jeeps will too (KJ/ZJ/YJ/TJ), but you should have no trouble finding a cheap 3.55 geared XJ axle.

 

 

Do you have access to basic tools? jack? stands?

[comanche1989]

plenty for a $150 junkyard axle. :yes: try car-part.com but be sure to search for XJs and MJs and various years of them. newer is better, but any will do if they are in decent shape. any XJ/MJ rear axle will go in with minimal effort. and other Jeeps will too (KJ/ZJ/YJ/TJ), but you should have no trouble finding a cheap 3.55 geared XJ axle.

 

 

Do you have access to basic tools? jack? stands?

I have access to a service garage that i can rent for cheap. Will swapping out the rear axle require bleeding the brakes? and will the truck be fuel efficient at 55-65 MPH? I commute to work on the highway.

[Pete M]

yes and yes.

 

that's why I recommend the 355s. if you're running stockish tires, you don't want to get too crazy with the ratios. my 88 (3.07s) was running 30" tires and I got both performance and fuel economy back when I swapped to 3.55s. :thumbsup:

[comanche1989]

Pete, thank you so much for all of your help. Its nice that an experienced guy is willing to help a newbie. :cheers: *edit* And I heard I might have to cut the leaf spring mount and reweld it if I get an xj axle?

[skidoo_j]

Pete, thank you so much for all of your help. Its nice that an experienced guy is willing to help a newbie. :cheers: *edit* And I heard I might have to cut the leaf spring mount and reweld it if I get an xj axle?

 

True an XJ axle rear leaf to leaf is about 2.5-3" narrower. So you have to cut off the spring perches and weld on new ones. This is when you decided if you;re going to go spring over axle too...

 

i bought new perches from ruffstuffspecialties but just about everyone sells a version. I went with them because i went soa and they had the longest perch to help prevent axle wrap.

[comanche1989]

Pete, thank you so much for all of your help. Its nice that an experienced guy is willing to help a newbie. :cheers: *edit* And I heard I might have to cut the leaf spring mount and reweld it if I get an xj axle?

 

True an XJ axle rear leaf to leaf is about 2.5-3" narrower. So you have to cut off the spring perches and weld on new ones. This is when you decided if you;re going to go spring over axle too...

 

i bought new perches from ruffstuffspecialties but just about everyone sells a version. I went with them because i went soa and they had the longest perch to help prevent axle wrap.

I have a little mig welding experience, would i be able to weld them? or should i bring it to a shop to weld?

[Pete M]

It's about as easy as welding gets. Just be sure to stitch it an inch at a time and move around so you don't build up too much heat in one spot.

 

XJ perches are also on the top, and you'll need them on the bottom. :thumbsup:

[skidoo_j]

It's about as easy as welding gets. Just be sure to stitch it an inch at a time and move around so you don't build up too much heat in one spot.

 

XJ perches are also on the top, and you'll need them on the bottom. :thumbsup:

 

IIRC you have to hack them off even if going sua so the ubolts can go through.