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First time XJ build. End goal JeepSpeed 2700

LLLux31

NAXJA Forum User
Location
NJ
I recently picked up a bone stock 98 XJ 4WD 4.0 4 door. I would like to make this a gofast jeep that stays within Jeepspeed Class 2700 rules. I would like feedback on my parts selection below. I would like to run 35s and be able to hit the local trails while saving up for a hybrid cage.


- Lift Kit (No Shocks)
  • Full Traction 6” Long Arm 4-Link System
  • IRO HD Coil spring Retainer
-Shocks
  • IRO Bar Pin Eliminator Front
  • IRO Bar Pin Eliminator Rear
  • IRO Stud to Loop Shock Adapter
-Steering
  • DirtBoundOffroad High Clearance Steering Kit
-Motor Mounts
  • Brown Dog Offroad Super Kit Ultra Flex Rubber
-Frame Stiffeners
  • RuffStuffSpecialties XJ Chassis Reinforcement
  • RuffStuffSpecialties XJ Front Reinforcement
  • Ares Fab Rear Stiffeners
-Drivetrain
  • PORC 231J HD SYE
  • Adam’s Rear 1310 CV Shaft (Extreme Duty)

I know I'm missing shocks. I'm planning on getting everything installed and measuring travel to know what lengths to go with. Class rules limit front travel to 12" and rear 14".

For Jeepspeed 2700 would you suggest Bilstein 7100s, a Fox 2.5 shock with external bypass, or a Fox 3.0 shock?

Would you suggest 35x12.5 or 35x10.5 for gofast?

Anything I'm missing or should add?
 
I think I would recommend the following additional reinforcement.

-JKS shock mount adapters vs the iron rock because the size of the shaft bolt is much bigger.
-Boostedworks steering box brace
-Some sort of cross chassis trackbar brace
-TNT or other steering box spacer (TNT has a 4 bolt version in case you want to upgrade the steering box)
-Find a different set of rear bpe that don't rotate the shock mount orientation
-some sort of gas tank skid
-check rules but zj gas tank swap if you aren't already going with a fuel cell

-not sure if you can alter wheel base or how much you can alter the chassis but buy one of the following or build your own
-Iron Man front shackle mount for extended wheelbase options
-i believe rustys off-road has a shackle box reinforcement

That's all I can think of as far as general strength modifications. Now disclaimer, I did not look at the rules for your class so your mileage may vary. Lol
 
Update: Parts Purchased and Build List Items Changed

I've purchased the Full Traction 6" Long Arm Lift Kit, Ruffstuff mid frame stiffeners, and Dirtbound Offroad High Clearance steering.

After looking at the JKS & IRO bar pin eliminators the JKS do seem to be more stout. I will also be going with the SYE/Drive Shaft combo from Adams directly. Will be contacting them today to see if they can build the shaft from .120 wall instead of .08.

Updated build list. Items in bold have been purchased.

- Lift Kit (No Shocks)
  • Full Traction 6” Long Arm 4-Link System
  • IRO HD Coil spring Retainer
-Shocks

  • JKS Front lower bar pin eliminators
  • JKS Front upper shock adapter
  • Boostwerks Rear Shock Towers
  • Undecided on shocks still. Rules limit to 2.5" w/ bypass or 3.0 smoothie.
-Steering
  • Dirtbound Offroad High Clearance Steering Kit
  • Boostwerks Ultimate Steering Brace
-Motor/Trans Mounts
  • Brown Dog Offroad Super Kit Ultra Flex Rubber
  • or SFR Ultimate Drivetrain Mount Package (Includes trans mount)
-Frame Stiffeners
  • RuffStuffSpecialties XJ Chassis Reinforcement
  • RuffStuffSpecialties XJ Front Reinforcement
  • Ares Fab Rear Stiffeners
-Drivetrain
  • Adam's driveshaft with Teraflex mega short sye
Once it gets to the point it's driveable and can take it out testing I will be adding to this list as I figure out the short comings/break stuff.
 
Forget the JKS stuff if your going to race. T&J performance (714) 633-0991 makes a good upper shock mount that you would weld and bolt in and a kit for air bumps that you would all tie in to the engine cage. Call them they know/ are Jeep Speed and used to offer full kits.

You could go either way on the shocks but what ever you choose talk to the mfg. and see if they offer any free tuning days and if they have a recommendation as far as valving to get you in the ball park. 3.0 bypass if you have the coin. Fox, King, Radflo, or Bilstein not FOA.

Springs- Deaver coils and leafs or Pac racing springs for the front.

https://www.deaverspring.com/products/jeep-leaf-springs/cherokee-xj-1984-2001/

http://www.racingsprings.com/Jeep-Speed-Lift-Springs/sku/301

You may like the Currie Anti Rock as a sway bar.

You don't need the mega short sye. That's better suited for the short wheel base Wranglers. I think most guys when they do run 4x4 use a standard sye. If you blow your t case and someone loans you one, your drive shaft will be too long. A lot of the guys were 2x and run a beam front.

For tires I think you still need to run Generals, maybe run 33x10.5 as you may want to run 2 spares and your not rock crawling. Keep it light. You can order you General tires and KMC wheels thru JS.

You running a stock 4.0L?

A good build thread although I don't thing he ever got to race it.

http://www.naxja.org/forum/showthread.php?t=1020245

Safety equipment adds up fast. Firesuit, helmet, Hans, comms, Lowrance, transponder mount, Parker pumpers, etc.

It is a hole lot of fun! But costly not only in $$ but time spent prepping and building.

Where in USA? Have you signed up on the Jeepspeed forum? There are a lot of good builds and pics there. Chris Nissley is finishing a new 1700 that is worth a look.
 
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Forget the JKS stuff if your going to race. T&J performance (714) 633-0991 makes a good upper shock mount that you would weld and bolt in and a kit for air bumps that you would all tie in to the engine cage. Call them they know/ are Jeep Speed and used to offer full kits.

You could go either way on the shocks but what ever you choose talk to the mfg. and see if they offer any free tuning days and if they have a recommendation as far as valving to get you in the ball park. 3.0 bypass if you have the coin. Fox, King, Radflo, or Bilstein not FOA.

Springs- Deaver coils and leafs or Pac racing springs for the front.

https://www.deaverspring.com/products/jeep-leaf-springs/cherokee-xj-1984-2001/

http://www.racingsprings.com/Jeep-Speed-Lift-Springs/sku/301

You may like the Currie Anti Rock as a sway bar.

You don't need the mega short sye. That's better suited for the short wheel base Wranglers. I think most guys when they do run 4x4 use a standard sye. If you blow your t case and someone loans you one, your drive shaft will be too long. A lot of the guys were 2x and run a beam front.

For tires I think you still need to run Generals, maybe run 33x10.5 as you may want to run 2 spares and your not rock crawling. Keep it light. You can order you General tires and KMC wheels thru JS.

You running a stock 4.0L?

A good build thread although I don't thing he ever got to race it.

http://www.naxja.org/forum/showthread.php?t=1020245

Safety equipment adds up fast. Firesuit, helmet, Hans, comms, Lowrance, transponder mount, Parker pumpers, etc.

It is a hole lot of fun! But costly not only in $$ but time spent prepping and building.

Where in USA? Have you signed up on the Jeepspeed forum? There are a lot of good builds and pics there. Chris Nissley is finishing a new 1700 that is worth a look.

Why do you not recommend FOA? I've heard they have gotten better in the last few years? :dunno:
 
Why do you not recommend FOA? I've heard they have gotten better in the last few years? :dunno:

Because:
Go look at their facility.
3 out of 4 shocks are typically not going to be 100% perfect.
They do not hone the ID after welding on bypass tubes.
And then they are Cheap.....
 
Why do you not recommend FOA? I've heard they have gotten better in the last few years? :dunno:

If your only playing in the dirt, plan to trailer it home and it's just a reservoir or coil over you may like them. The custom bypasses we waited weeks for would not extend with a nitrogen charge of 250psi.

For something going in a race car I would pay the difference and get a great shock from the get go, and tune them.
 
Because:
Go look at their facility.
3 out of 4 shocks are typically not going to be 100% perfect.
They do not hone the ID after welding on bypass tubes.
And then they are Cheap.....

If your only playing in the dirt, plan to trailer it home and it's just a reservoir or coil over you may like them. The custom bypasses we waited weeks for would not extend with a nitrogen charge of 250psi.

For something going in a race car I would pay the difference and get a great shock from the get go, and tune them.

Good to know, I'm in the market for shocks for my Ranger build and my Jeep close behind it... I would definitely hate spending any money with FOA just to regret it. I use my trucks pretty hard, I'll definitely go with something quality :thumbup:
 
It's been a bit but I'm back with an update. We launched our social media/website (http://dobermanracing.com & http://instagram.com/dobermanracing).

We got in our lift kit from Full Traction, frame stiffeners, and DBO steering. We're flying out to the Mint 400 in 2 weeks to talk with others in our class, check out other class 2700 vehicles, and to meet some vendors for the remaining parts we need.

Our class tire size limit 35" and 3" diameter shocks with bypasses or 4" smooth body. Going to see what others are running and get some advice on running 2.5" or 3" with bypasses. From what I understand Fox makes a better shock but King has better customer service.

Once we get back from Vegas assembly will begin and I'm going to be reaching out to a few shops/businesses I have a relationship with about getting a sponsorship to cover the cost of the cage. If that doesn't pan out I just paid off the credit card ;)

Our first race will be in August for Vegas to Reno.
 
Ok well this is where I'm currently at and a history added in.


This is the 98 XJ the day after I bought it for $1250 with 130k miles on it. I picked it up towards the end of 2017 and have been daily driving it since then. I replaced a freeze plug on the back of the head and while I had the head off did a new head gasket and exhaust manifold gasket. The neutral safety switch sometimes acts up but not enough that I've felt the need to swap it. I'll end up bypassing it with the paperclip trick.

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About two weeks ago I moved the Jeep and the parts I had over to my buddys garage. He ended up being a life saver otherwise I would have been building this on the street in front of my house.

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My little 2-ton jack stands just weren't going to cut it so I had to step up to 12-ton stands.

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(that piece of cardboard was from the previous vehicle in this bay, the jeep didn't leak all that)

So I removed all the stock components except the upper control arms and cut off the front lower control arm mounts.

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Bolted up the new trackbar mount and brace.

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Had to drill a 9/16" hole through the frame which I did not have a carbide bit for so that was a pain.

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The rear was simply a leaf and shackle swap.

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I'm still not positive I'm going to keep the FT leaf spring plates. It depends on where I end up mounting my rear shocks.

At this point I put it on the stock wheels just to see what it looks like.

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Then went back and reamed the knuckles to 5/8" to fit the DBO steering kit. This is with the stock pitman arm but I ended up swapping to the 1" drop FT pitman arm.

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and then realized this isn't going to work

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So I grabbed some 2" spacers to match my new rear axle and let the stock wheels clear the OTK steering.

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I tossed on some regular shocks that I picked up for $150 from IRO just to be able to drive around until I get my bypass shocks/cage done.

I also bolted up the stock front shaft for now after doing a JB Conversions 1310 SYE kit. I decided on the JB Conversions kit over the Advanced Adapters kit because their yoke has larger cut outs for more shaft flex and it's a 2" kneck all the way down.

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I also found a 79' Bronco Ford 9" big bearing rear axle. I pulled it apart, cleaned it up a bit and tossed a coat of paint on it to prevent it from rusting. I know I'll have to grind a lot of it off when I weld on the spring perches, shock mounts, and truss.

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Not sure if I was suppose to get paint on the gasket surface. I also picked up perches from Barnes4WD. Going to make the shock mounts myself.

Going to bring the 9" over to my buddies garage and find out where they need to be for the pinion angle. If my math is correct and XJ spring perches are 44" center to center then I need to come in 7" from the end of the 9" (measured without axles) for the perches.

I also picked up 25' of nickle/copper 3/16" brake line and fittings so going to redo the brake lines. The front are fine but I snapped the rear removing the stock soft line.

Also going to be ordering a 9" disc brake kit. I haven't settled on a kit yet but leaning towards this one or a similar one.

https://www.jegs.com/i/Right-Stuff/965/ZDCDS05/10002/-1

This kit says it will fit with 15" wheels so hopefully that is true and I can keep my stock wheels. I'll just need to take my stock 31 spline axles and have them redrilled or pick up a new set already drilled for 5 on 4.5. If I have to replace them I will most likely make the jump up to 35 spline shafts. For lockers I will be keeping the front open for now and doing a detroit in the rear. I can get a used detroit of ebay for $200-ish but I have not seen a 35 spline detroit except new for around $600.

With the front spacers my WMS to WMS is 64.75". The rear is 65". My wheels are 15x7 with 5.25" back spacing. If my math is correct then running a 35x12.5" tire will put my outside edge to edge at 79.25" front and 79.5" rear. Jeepspeed 2700class rules are a max tire edge width of 81".

I'm learning as I go along so if anyone sees any mistakes or has suggestions I'm all ears. We were hoping to make it to V2R and race but I may have to push it back the next race or the following one which will be in Jan for the 2019 season. If we end up not racing this year I'll probably go ahead and do a front axle swap. Just not sure if I want to go to a D44 or D60. I know the D60 will be heavier and sit lower but the additional strength would be nice as when we're not racing I will be wheeling on east coast trails/rauche creek.
 
I wouldn't try doing go fast with 2" wheel spacers and 35" tires, the D30 unit bearing don't like big tires and go fast, let alone with 2" spacers.




I may end up swapping the front axle before the first race. I don't expect them to survive long if I have to run the 2" spacers.
 
Updated parts list. Everything here is what I've done to the XJ so far. Over the last few months I've learned a lot about racing and what it takes to be competitive in terms of the build. I've change a lot from my original plans as I realized what I wanted to build would not be strong enough. Racing in 2018 didn't happen but we should be much much much more prepared to race in 2019.


- Lift Kit (No Shocks)

  • Full Traction 6” Long Arm 4-Link System
-Steering
  • DirtBoundOffroad High Clearance Steering Kit
-Motor Mounts
  • Brown Dog Offroad Poly Mounts
-Frame Stiffeners
  • RuffStuffSpecialties XJ Chassis Reinforcement
  • Stinky Fab Racing Steering Box Spacer/Reinforcement
  • Boostwerks Engineering Ultimate Steering brace
-Drivetrain
  • PORC 231J HD SYE
  • Adam’s Rear 1310 Shaft
  • Adam's Front 1310 Shaft
  • 79' Bronco 9" Housing
  • Yukon Nodular 3rd member w/ 3.25" carrier bearings
  • Detroit locker (rear)
  • 5.13 gears
  • 31 spline axles (rear)
  • big bore gm metric calipers w/ f150 rotors (rear)
-Tires

  • 37x12.50r17 Cooper STT Pros on 17x8 Vision wheels
-MISC

  • Ironman4x4 trackbar mount
  • Dodge Dakota Master Cylinder
  • Summit Racing Adjustable Prop Valve




I still plan on competing in class 2700. I put 37s on it and cheap shocks just to get it driveable while I build it up. We will have a seperate set of wheels/tires to comply with the rules.


Got the detroit in the 9". Only took me about 18 hours working in the corner of my shed with a small led light (electricity not run to the shed).

I've never done gears before so invested in a magnetic dial indicator, inch lb dial gauge, home made spanner wrench, and rented bearing/race press cups, bearing race puller and accompanying slide hammer from autozone.

I original was going to run a crush sleeve eliminator but the one that came in my kit was too thin and didn't have enough shims to even contact the bearings on the pinion. I went through 2 crush sleeves before find out a trick to make it easier to crush them.

I assembled the pinion and bearings into the Daytona pinion carrier and push the whole assembly in my press. Then pressed out all the slop until the bearings were seated in the support. Then put the yoke in my vise and used a 3ft breaker bar to tighten the pinion nut until I had resistance turning the pinion support.

I would tighten a little and then check the preload on my dial indicator.

Then adjusted backlash and verified on multiple sections. Spec is 0.006-0.010" and I'm at 0.008.

Then I ran a pattern with the marking compound and was able to get a good pattern. I started off with a 0.020 shim, went up to 0.045 then 0.027, then 0.035, and ended up at 0.039 asy final pinion shim pack.

I then ran a die over the housing Studs and cleaned up the threads. I still need to pull the 3rd member and put on a lube locker gasket and pinion support o-ring. I just stuck it on the housing so once I press on new axle bearings, axle retainer plates, axle bearing seal, and axle bearing retainers I can put the axles in and get my brake caliper positioning to weld on the caliper brackets.

Also holy crap caliper banjo bolts are ridiculously expensive. Almost $35/ea. Luckily Speedway Motors sells a stainless line kit for my rear calipers that was $49.99 and came with 2 lines 2 banjo bolts and the required tabs.



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Ordered the wrong axle retainer plates so I made my own out of 1/4" instead of the 3/16" these came in.

Then cut off the old bearings and seals. Pressed new Timken bearings and seals. Installed the 3rd member with a lube locker gasket. Torqued everything down.

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Got the 9" swapped in.

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Stops much better now with disc's in the back.

Was 95° out and welding on the blacktop was so much fun and fun fact sometimes if you touch something you just welded you can hear your skin sizzle before you feel it lol.

I started at 2 and finished at 9. Only had to run to autozone twice (caliper guide pins, brake hard-line fittings). Although I do need to go back and return the fittings I didn't use. Wasn't sure on the thread size so I bought them all. Toss in a pizza break, and having to explain what I'm doing when my neighbors come to chat. The more I do to the Jeeps more and more people keep stopping to see what I'm doing now. I'm almost dead center of my development but my road is one of the main roads through the development so I'm collecting some fans

I may end up switching the caliper pins over to another set they had at autozone that has a cotter pin in the end so if the pin backs out of the caliper mount it cant completely seperate and will prevent you from losing a caliper.

Now it's a 98 Jeep Cherokee with a 79 Ford Bronco read end and 78-88 GM big bore calipers which can be found on the front of an S10 up to 2002 . The calipers I got from Speedway motors because they are affordable, came with pads, and have a larger metal piston at 2.75". These combined with the Dodge Dakota master cylinder upgrade the brakes work fantastic.

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I ended up cutting the stock shock mounts off the c8.25 and used them on the 9" until I get bypass shocks and pull them up through the floor. I already have barnes4wd mounts to go on top of the axle .
 
Kept creeping up to 225-230 on the highway. Head gasket I did last year, so swapped out the water pump for a Gates pump and a Champion 2-Row all aluminum radiator.


Now no matter how hard I push it the temp stays at 205-207. The champion rad is much much lighter than stock.
 
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