Refreshing the TJ - Build Thread

GP'd

Adventurer
Found a few hours to get the hoops and accessories prepped for the next stage. I have a few more small gussets to prep and dimple die. I'm using the flat tube couplers as frame landing plates.

 

GP'd

Adventurer
The rear coilovers, new TRE and Fox Steering Stabilizer were installed on Saturday.

Sometimes getting the coils out gets hairy...



Before... and After... More details on what happened to the FOA's to come.



Droop



New TRE's to install. A bit frustrated that Currie steering requires the entire bar to be replaced for worn out TRE's




On Sunday I started a bit early...



Sunrise was beautiful



Beauty shot of the 1800


Old buckets cut off






I took some flex measurements again



Got the hoops in and put the coilovers in at full droop



Partially tacked up hoops. Excuse the ****ty welding, trying to tig weld outdoors with a slightly windy day = frustrating.



How it is sitting now



This coming Saturday I hope to get the hoops and bump cans fully welded, cross bar in and finding how to relocate and all the under hood components...

 

GP'd

Adventurer
This past weekend I was able to finish the welding from last weekend, and get the crossmember mocked up.







Still routing some of the hoses for smog equipment.









 

GP'd

Adventurer
Suspension Starting Points : Jeep Empty (Need to re-calculate weight using springs)
12" Front 6.75" Up travel (.75" Bump stopped) (6.00" Up / 5.25" Down) 190 PSI
10" Rear : 5.00" Up Travel (Unloaded) (5.00" Up / 5.00" Down) 180 PSI

More tuning details and initial impressions to follow when I get a chance to drive it more than 30 minutes around town.
 
Last edited:

GP'd

Adventurer
As usual I'm a bit late in responding...

Here is where I started with my tuning and initial coilover set up. By writing down what I need :

Why we are here : In mid 2011 I bought FOA Shocks. In early 2012 they were leaking nitrogen. From 2012-2013 I decided to just keep filling them. In 2013-2014 they started leaking oil in addition to nitrogen. Today nitrogen is in the shock body on 2/4 and 2/4 leak oil badly. I don't want to spend money or time rebuilding them. I want to invest in shocks that have durability and more reliability and have no interest in buying smoothie shocks when I'm 50% set up for coilovers. My old man emu coils also have a nice Iron Oxide coating that replaced the powder coat, I can't see them hanging on much longer.

So right now : I need new shocks and I need new coils, the rear is already set up with Synergy Coilover Buckets. Front I kind of copied synergy's coilover tower, but never executed it to handle the force of a coilover. I plan on cutting this and the factory coil bucket off and going tubular. I do understand that longarms would be a great addition, but it isn't in the cards right now. Tune-ability with my current setup is what I'm going for and I can't see a disadvantage other than cost in running coilovers in place of my current coil/spring set up.

In effort to start off as close to what I want future bound for my system, here is my diatribe :

What drives my preference to tune / spring the Jeep for :

Forest Service Roads/Desert Trails = 40% Importance
Washboards/Ruts/Small Rock​
Typical FS Trail/Desert Conditions​
Think High Mountain Road/Pozo Rd/Elkhorn Rd)​
(Think Mojave Road)​
Winding Paved Mountain Roads = 20% Importance
Stable control of vehicle at speed limit in cornering.​
Highway Driving = 20% Importance
Rock Crawling = 20% Importance]
Currently this is what I do the least of but plan on changing this.​
(Think Rubicon)​



My typical trips consist of 2-10 Hours of driving mixed highway and winding roads to get to the trailhead. From there I'm usually Camping/Fishing in the backcountry where I spend a weekend doing 20-50 miles on average driving on Forest Service/Desert Trails.

Rock crawling isn't exactly something I've spent much time doing in the past, but that has changed recently and want it to be considered into the shock tune on the vehicle.

Highway Driving is also important due to the amount of time I spend in the jeep, but I feel that the previous three priorities should cover my needs on the freeway as well.

I am interested in the Compression adjusters as I have found myself doing a variety of trips, some fully loaded in the back some, fairly light. Having the ability to have a smooth(er) ride and still have compression adjustment available sounds like a good idea in theory in these situations, however, in practice I have no experience with King's adjusters.

Current Stats :

2000 Jeep TJ

PowerTrain:
Engine : 4.0
Transmission : AW4 - Tiptronic Modified Winters Shifter, Modified Valve Body, In-line Filter, Temperature Sensor, Pressure Sensor, Dual Front Coolers on PSC Mount.
Transfer Case : NP231 - SYE

Drivetrain:
Driveshafts : Custom Coast Driveline
Gear Ratio : 4.56
Front Axle : Dana 30. 27 Spline Chromo Shafts. ARB locker. Soon to be sleeved/Knuckle Gusset
Front Tires : 265/75/15 Future bound will be 285/75/16
Front Mount Lengths : Currently running 18.3 Collapsed. Plans to go to a tubular hoop so this is adjustable. Open to input/ideas.
Estimated Axle/Tire Weight : ~460

Driveshafts : Custom Coast Driveline.
Rear Axle : Ford 8.8 w/ Tracloc
Rear Tires : 265/75/15 Future bound will be 285/75/16
Rear Mount Lengths : 18.3" Collapsed.
Estimated Axle/Tire Weight : ~430

Suspension - Front
Control Arms Front : Currie Johnny Joint. 15.75" Length
Control Arm to Ground : 10.5º
Coilover to Vertical : 4º
Coilover to Control Arm : 76º
Coilover to Vertical (Camber) :
Sway Bar Front : Currie Anti Rock
Front Spring : OME 933 - 140 in/lb Spring Rate
Bumpstop : Prothane coil insert
Front Shock Showing : 5.5" / 11.5" travel = ~48%
Approximate Corner Sprung Weight Front : 1000 / Loaded, 975 / Unloaded(w/passengers)

Control Arms Rear : Currie Johnny Joint. 15.5" Length
Control Arm to Ground : 10º
Coilover mount to Vertical : 22º
Coilover mount to Control Arm : 82º
Coilover to Vertical (Camber) :
Sway Bar Rear : Factory
Rear Spring : OME 942 - 160 in/lb Spring Rate (too heavy unless heavily geared up)
Bumpstop : Prothane coil insert
Rear Shock Showing : 4.5" / 10.5" travel = ~43%
Approximate Corner Sprung Weight Rear : 1184 / Loaded, 905 / Unloaded(w/passengers)

Body :
Daves Custom Boatsides
AEV Highline Fenders
Poly Performance Front Cage then bastardized to a full cage.
UCF Full Aluminum Skid
Savvy Aluminum Gas Tank Skid
Front Bumper - In state of being built
Rear Bumper - In state of being built
PRP Seats
 

GP'd

Adventurer
Screen Shot from the "The BillaVista Preliminary Spring Rate Calculator - © 2008 Bill "BillaVista" Ansell, All Rights Reserved." Check out the website; tons of great information. http://billavista.com/



Round One.

Front : 12" Coilover Length. ~11" of Travel
Upper Spring : 300 in/lb 12" Coil​
Lower Spring : 14" 250 in/lb Coil​
Pressure : PSI 210​
Compression : Adjust 2/22​
Sway Bar : Anti Rock Middle Setting​
Rear : 10" Coilover Length. ~9.5" of Travel
Upper Spring : 350 in/lb 10" Coil​
Lower Spring : 300 in/lb 12" Coil​
Pressure : PSI 210​
Compression Adjust : 2/22​
Sway Bar : Factory​

Initial Impressions almost spot on with the previous suspension. The OME Coils were ~140 in/lbs Front / 160 in/lbs rear. If you look at the resulted inputs ki(lbs/in) the starting numbers were very close. The rear was softer, which is something I wanted, and this softness was a result of the 22º angle of the coilover using the same spring rate. After driving it around for a few weeks and testing the articulation (as best i could) I got the impression while it handled great on the street, the jeep was over-sprung for anything offroad. After calling some buddies and then talking to King and Poly Performance, we decided to drop the upper springs both front and back by 100 in lbs.

Round two.

Front : 12" Coilover Length. ~11" of Travel
Upper Spring : 200 in/lb 12" Coil​
Lower Spring : 14" 250 in/lb Coil​
Pre-Load : ~.75"​
Droop/Bump : ~50/50%​

Pressure : PSI 150​
Compression Adjust : 2/22​
Valving : Flutter Stack 15/10​
Sway Bar : Anti Rock Middle Setting​

Rear : 10" Coilover Length. ~9.5" of Travel
Upper Spring : 250 in/lb 10" Coil​
Lower Spring : 300 in/lb 12" Coil​
Pre-Load : ~1.25"​
Droop/Bump : ~50/50%​

Pressure : PSI 150​
Compression Adjust : 2/22​
Valving : Flutter Stack 15/10​
Sway Bar : Factory​

Vast Improvement. Though minor number wise, the drop of 100 in/lbs at each corner allowed the suspension to flex more and also better controlled suspension events than the over-sprung suspension from before. The other major change was dropping the PSI in the coilovers from 210 to 150 PSI. I was advised that this would make minor changes, however, the change felt quite drastic to me. While bumps,potholes,etc were much better managed by this spring change, it came with an issue; Body Roll. Round 1 was very stable and sharp on road almost feeling like a car. Round 2 there is noticeably more body roll. While I felt this was an issue initially, I am at the minimum compression adjustment and lowest PSI Setting. Bumping the PSI and dialing up compression return the roll or lack there of very close to where it was before.

So. Where am I going from here?

Finding time for testing. With my ride height where I want it and the suspension dynamics fairly balanced, next is playing with pressures/compression adjust and valving. My initial impression right now is that the Flutter Stack 15/10 is a bit stiff on the compression side. I'm guessing I would be better suited with a Flutter Stack 12/10, but time will tell.

Now that the jeep is riding and handling better than ever, it's time to focus on some of the Gremlins :

No Reverse Lights
Front Axle Wiggle (Suspect Trac Bar Bushing and Control Arm Bushings)
No Center Console or Cup Holders
Chipped Starting Ring (1/30 starts requires me to roll the car a few inches to get the gear to engage.)
Rear storage system.
Skid Plate Rattle (Need to reverse bolt direction hitting exhaust)
Rear Axle Breather Leak
Rear Tub holes (For reservoir pass through)
Transmission Pressure Gauge (Still not working)
Evap Circuit (not showing available on OBDII)
Cruise Control Turning on but not working.
 

GP'd

Adventurer
New Rubber!

285/75/16 BFG AT KO2's

I decided to go with the bead balancing this time and purchased .36 gram 6mm high quality airsoft pellets from Amazon : http://www.amazon.com/gp/product/B00N1KHKHC/ref=od_aui_detailpages00?ie=UTF8&psc=1

Using the chart Equal has on their website : http://www.imiproducts.com/assets/pdf/equal-quantity-chart.pdf I determined I needed 6 oz Minimum per tire. Cross referencing a few of the other internal tire balancing options (http://www.innovativebalancing.com/BigTirechart.htm) between 6-8oz is the range suggested for the 285/75r/16 tire. One bag of the BB's above weights about 38.10 split among 5 tires gave me about 7.6 oz / tire.

I've only driven for 10 minutes today, but the tires felt flawless from 0 - 70 mph. Looking forward to putting more miles on them.

Now for some crappy cell pics...







Heading out to King of the Hammers next week with the Jeep for the race. Who's going?

Few other updates :

Rear fenders will need to be trimmed a bit. After driving 1100 miles with weight in the back the rear springs settled. I think I need to put another inch of preload in. Probably going to play around with the rear a bit this weekend.
 

Jurfie

Adventurer
Wow, first time seeing this build thread; great job and nice TJ! I'd love to get an LJ and do something similar.

Coilovers = :drool:
 

GP'd

Adventurer
Day 2 of new tires.

Smooooothhhh.

My Goodyears were fairly cupped and very difficult to balance. I had minor vibes no matter what pressure or speed I was going with the tires and they were loud as hell!

These new BFG's are quiet, and balanced perfectly even at 70-75 mph. The BB seem to be doing the job. Upon coming to a stop you can hear them fall and hit the rim, kinda sounds like pouring cereal into a bowl. Hardly noticeable. They fall out of rotation at around 1-2 MPH coming to a stop. At starting again you can occasionally hear them bouncing around until you hit 15-20 and they find their home around the outside of the tire.

Given that they are E rated tires, the shop definitely overinflated them for the weight of the TJ. I'll be playing around with chalk today to determine the right pressure.

After the two long road trips over the next weekends I'll report back on mileage changes a bit more road characteristic feedback.

Specs on the tires...Out with the old...


...and in with the new...

 

GP'd

Adventurer
Made it out to Stanislaus National Forest this past weekend and constantly fought closed gates for 'winter', which right now in California is 65º weather.

Fortunately that didn't stop us from having some fun with cameras and the cars :


New BFG's :




Playing around with a new Camera :





















 

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