ZMotorSports 2011 JKUR Build Thread

I am new here but thought I would throw up some pictures of my latest Jeep build. It is not real time as I have owned it now for almost two years.

I bought the Jeep with only 3208 miles on the odometer and commenced building my "Dream Jeep". This is my daily driver and weekend wheeler.

On lift just before sitting it down with the 4" BDS Suspension Lift and 35" KM2 tires/ATX Crawl wheels.

Backed outside the shop after just barely sitting her on the ground with new lift and tires/wheels.

More to come as I dig through the pictures. Also pictured here is the Warn Rockcrawler bumper/Powerplant combination that I purchased used just to get me by until I could fabricated my own bumpers.

Mike.

 

[zmotorsports]

I posted a walk around video of my 2011 Jeep Wrangler to my YouTube channel last night so I thought I would put a link here.

Thanks for following along.

Mike

 

[zmotorsports]

With the summer heat in full swing I figured I would address cooling. I have been asked a lot lately about my Jeep JK with the LS engine and cooling. This is a "hot" topic on many of the Jeep forums even without running an LS engine so I thought I would comment. As I drive around I see a LOT of JK's with winches mounted on top of the front bumpers, large plated stingers out in front of the Jeep's grille and then there's those angry grilles and mesh or inserts that people put on their JK's that do nothing more than obstruct airflow and make it harder for the car's cooling system to function. I'm not only talking about JK's with V8's but also stock drivetrains that are having heating issues.

Take a car designed for 29" or 32" tires that weighs around 4500 pounds and the stock cooling system does it's job as designed because it requires a certain amount of energy to get down the road. The Jeep JK is already about as aerodynamic as a brick but in stock form it performs as designed. Now take and add 2-4 inches of lift and run 35-40 inch tires and you have an even less aerodynamic brick that you're trying to get to push through the air with more weight and rolling resistance. The Jeep will do it, even with the anemic 3.8 liter engine in the 2007-2011's but it adds stress to the system. This is one of the biggest reasons that I stayed at 35" tires for the first 8 years and 92k miles was because I was stressing the system as much as I dared and I was running a sunken winch as well as no obstructions to the grille.

The grille area on these JK's is not much. The opening only measures 11" in height and let's just call it 26" in width although it is slightly less, I'm being conservative. That is only 286 square inches of cooling surface area to expel the heat, or dissipate the heat. Technically it is less than that because you have 6 vertical bars that create the 7-slots that the Jeep is known for. Each vertical bar is 1.5" wide and 11" tall for 16.5 square inches each or 99 square inches of blocked area. Now you only have about 187 square inches to allow air to flow through the transmission cooler, A/C condenser (which is also putting off heat when the A/C is running) and then the radiator itself. The early JK's only used a 17" two-speed fan. Basically it reduces the voltage for low speed and feeds full system voltage for high speed but maximum airflow from that fan is only in the mid-2000 CFM range. The newer Pentastars have a better cooling fan that is PWM (Pulse Width Modulated) and 19" that is capable of over 3k CFM so much better performance. The Camaro SS fan that I am running is also a 19" PWM fan capable of around 4k CFM at 100%.

You can see just how the cards are already stacked against us JK owners before we start modding our babies. That is why it is so important to not design in any additional issues that will negatively affect the cooling system. While we're talking about mods we also can't forget about the engine bay itself and evacuating the hot air out of the engine bay. Many owners throw on a bunch of under-armor which also traps heat not allowing it to vent out the bottom as well as adds weight the engine has to overcome to push down the road. Another mod I see very heavily is the removal of the inner fenders when flat fenders are installed. This can potentially also create a restriction for hot air to escape if not done correctly. Inner fenders that fit tightly to the frame rails block off these gaps that were designed to allow for hot air to escape the engine bay so you can see how fast things multiply when dealing with heat and keeping the JK cool.

Now when you couple this with high elevation it gets even worse because as the air is thinner there is less of it to pull that heat away from the cooling radiator, although granted there is also less for combustion. Some people think this high elevation is good because it creates less heat in the engine but in fact as we go up in elevation we lose approx. 3% of output per 1k feet in elevation so your JK is having to work much harder at elevation to move its own weight with less performance.

Bottom line is when building your JK, or any car for that matter, think systems through so you're not fighting issues that you designed in down the road.

My Jeep for example is Black so it's a heat magnet and it's heavy @ 6k pounds. Granted I know of heavier ones with 40" tires and one-ton axles that are closer to 7k pounds but mines still heavy and it is lifted running 37" tires and has a lot of frontal area to push through the air. I am running OEM fenders and inner fenders, my winch is sunk down between the frame rails and my bumper does not block any grille area. I do have a fairly large transmission cooler and when I swapped in my 6.2 liter LS engine I also installed the A/C condenser for a manual shifted JK so it has more surface area as the automatic version condensers have a transmission cooler at the bottom of the A/C condenser, which I feel is not a great idea.

The past couple of days here in Northern Utah have been the hottest of the summer so far at 101-103 degrees. My lifted, Black JK has been running cool as a cucumber and performing flawless so it can be done. I have a 16-mile commute to work each day and driving to work in the morning at around 82-degrees ambient temperature my transmission temperature has been right at 135-degrees and my engine coolant temperature has been sitting right on the thermostat with temps of 194-197 degrees. That tells me I have adequate air flow through my grille as my cooling fan doesn't even come on.

Once I get off the interstate I have a couple of stoplights and about a mile section of 30 MPH where my cooling temps will climb slightly to around 208 when the fan comes on at around 15% and pulls the temp back down to 204 where it kicks off. This will continue to cycle and never rise above that 208 mark, which is far from hot on a modern engine.

Yesterday driving home in triple digit heat and stop & go traffic on I-15 with my A/C running it was cool inside my Black Jeep with the transmission temperature around 165-degrees and my fan running around 28-36% and keeping my engine under 200-degrees. My PWM fan is controlled 100% by the GM ECM as it is getting feedback from the other systems and the fan percent is set by prioritizing the inputs from A/C condenser pressure, transmission temperature as well as engine coolant temperature.

All in all, the GM LS engine does a great job in even a lifted, Black Jeep if done properly and some basic cooling system principles are followed.

Thanks for letting me ramble.

Mike

 

[mbryson]

I'm with you on the cooling on JKs. I had my 2012 with a winch mounted up into the grille area.

the blocked configuration that created cooling issues....

I could drive the Jeep in any weather with the blockage moved lower. Wasn't a huge fan of that bumper but it worked fine.

I could even tow without overheating. Towing this trailer might have been the only time on the highway I REALLY liked the 4.88 gears. Would have rather went with 4.56.

As you mention above, the JK is a flying brick as delivered. We lift them and put bigger tires on them and make them even worse. On a trip to Vegas in the fall in the JKU above, I averaged about 7 mpg staying at freeway speeds. The RPM the engine was running and the "aerodynamics" coupled with I 15 speeds between Payson-Vegas contributed to the poor fuel economy. I think I got gas in Beaver and again in St George on the way down.

 

[zmotorsports]

The aluminum radiator in my Jeep developed a small leak a few months ago and I have been waiting for a replacement under warranty. It showed up a few weeks ago but with the triple digit heat we’ve been having it has started to worry me so I thought I would get it replaced before we start hitting several Jeep rallies we will be attending over the next few months.

I stopped by my buddies shop Monday afternoon and evacuated my A/C system and pulled the radiator.
Last night I swapped the Camaro SS electric fan and the A/C condenser over to the new radiator.

Assembly ready for installation.

These JK’s are hard on aluminum radiators for two reasons, first there are so many electronics that they have issues with electrolysis so I added a ground strap directly from the chassis to the radiator shell. Secondly the Jeeps flex and have a tendency to crack aluminum radiators so to aid in allowing a little ability to move without cracking while flexing I added some springs under the rubber isolators. These seem to retain the radiator well yet still allow some movement.

Another issue I have seen on the JK’s is that people have a tendency to remove the rubber side flaps and lower radiator valances when they are installing aftermarket components such as transmission coolers, aux. lights and winches. These rubber flaps aid in cooling by keeping the airflow directed through the radiator core rather than around it under it so make sure you keep yours in place.

Here you can see on the passenger’s side I merely cut a slit to allow the braided transmission lines to run through it but the flap is still in place and fastened to the core support.

Driver’s side in place.

Upper radiator hose installed along with 1/4” line to the surge tank using tie-wraps to help conceal the surge tank hose. Another tip for keeping things clean and tidy is to loosely install the tie-wrap then rotate it so the lock is under the hose and out of site before tightening and using flush cuts to snip the tail. This does two things, the flush cut cutters eliminate that nasty sharp cut edge so you don’t get scratched by it and by not seeing the lock it provides a much cleaner overall appearance.

Ready to pull a vacuum on the cooling system and check for leaks and fill.

Double checking things after the test drive.

Now to recharge my A/C system.

Thanks for looking.

Mike

 

[rholbrook]

You need to fab up some sort of engine cover.

 

[zmotorsports]

Russ, I don't think I could fabricate one to look as good as the OEM GM engine cover and I like the OEM GM engine cover for the "stock" look.

That was one my goals with my LS swap, I wanted to have the GM engine cover as most all truck/SUV LS swaps that I have seen don't run an engine cover whereas with the LS3 many do because the intake plenum is so much lower. With most truck/SUV LS swaps when you open the hood you see the upper intake manifold and all of the wiring harness. It took some time but I was able to get the GM engine cover to work and I think it finishes it off nicely.

Mike

 

[Bart]

You may have mentioned this somewhere previously but where in the heck did you find that upper radiator hose? Impressive to say the least.

 

[zmotorsports]

Sorry, I don't think I mentioned that but it is an OE upper hose from a 2007-2014 Silverado/Denali. Bought this one at my local NAPA, part # 9867 or the AC Delco part # is 26559X. Again, this was to keep with my whole theme of trying to use OE off the shelf parts.

I did have to trim about an inch off of the engine side and 1.5"-2" off of the radiator side to get it to sit in the low spot on the shroud.

Mike

 

[zmotorsports]

My wife and I just returned from our annual Ouray, CO wheeling trip. This was our twelfth year in the area and by far the most interesting. The amount of damage and carnage from many, many avalanches was staggering. We’ve seen an occasional slide or avalanche area here and there but we counted about 17 this trip and that was just from one heavy snowfall season. Upon talking with a local who works at a historical museum in the area he said this was the highest snowfall on record since the 1880’s and by what we witnessed I have no reason to argue the point.

Many of the trails in the area were similar to years past with a few sections here and there that had larger rocks exposed and a culvert exposed that required some careful tire placement but overall a great trip. Two trails that I like to run were not open, Black Bear Pass and Poughkeepsie Gulch. I talked to a Forest Service ranger one day and was informed they were working to get Black Bear Pass open within a week or so but had no plans to work on Poughkeepsie this year as they didn’t have the resources to work on both this season.

For the last four years my wife and I had hosted a small gathering in the area(12-15 couples/RV’s/Jeeps) but this year we weren’t 100% sure we would be able to make it with our son’s home purchase and wedding so we didn’t organize anything. We were able to get away and it turned out to just be the two of us although we met a few people in the campground that had asked if they could tag along with us after discovering that we were familiar with the area.

Now for the pictures.

Our campsite for the week.

Day one it was raining and upon driving over Corkscrew Gulch, Hurricane Pass and California Gulch the damage was very evident.

However, the natural beauty of the area was still very obvious.

And with the heavy snowfall last winter the sheer amount and size of the waterfalls were probably a once in a lifetime experience. We have never seen so many waterfall in this area. Around nearly every turn we would comment about seeing “another” waterfall.

Thanks for looking.

Mike

 

[zmotorsports]

I almost forgot to include some gratuitous pictures of our Jeep in her element.

Then after returning home yesterday proceeded to wash and detail both the Jeep and the coach in preparation for the next RV/Jeep adventure.

Thanks for looking.

And for anyone interested, the new powertrain really performed fantastic and the 37’s really flattened out the trails this year. Especially seeing as how the rocks were a bit larger this year as all of the water had washed out much of the dirt and left just the large rocks exposed. The Jeep handled them in stride and I couldn’t be more pleased with the way everything performed.

Mike

 

[anderson750]

What is the tank on the dolly with the hoses hooked to it?

 

[zmotorsports]

What is the tank on the dolly with the hoses hooked to it?

That is my deionized water system for spot free rinsing of my coach. Saves a LOT of chamois work with that much real estate to dry.

On my YouTube channel I have a video of building the cart that I fabricated and the components that I purchased from DI Rinse.

Mike

 

[anderson750]

I am going to look into that since this is what I am having to clean now. I have never been motivated enough to chamois off when I had my toy hauler and this is even more to dry off if I was motivated.

 

[Pile of parts]

That is my deionized water system for spot free rinsing of my coach. Saves a LOT of chamois work with that much real estate to dry.

Mixed bed, I assume. Who do you do your exchanges through? Sorry, I worked a few years in water treatment. Nothing like have your own spot free rinse!

 

[zmotorsports]

I am going to look into that since this is what I am having to clean now. I have never been motivated enough to chamois off when I had my toy hauler and this is even more to dry off if I was motivated.

Nice showhauler/Super C. Yes, that is a lot of real estate. When I had my 26' enclosed race trailer with OAL of 72' it was very taxing to clean everything. I usually had to clean everything twice, once when we returned from a trip then before we left because the coach and trailer sat outside. Now my coach sits in a heated shop so my washing cycles were cut in half as I only have to wash it when we return from a trip and the rest of the time it stays nice and clean inside my shop. It's still a lot of work and I wish I would have used the deionized water sooner and saved all of those hours of drying over the past 25+ years of owning RV's.

Mike

 

[zmotorsports]

Mixed bed, I assume. Who do you do your exchanges through? Sorry, I worked a few years in water treatment. Nothing like have your own spot free rinse!

When the time comes I will just purchase the new resin and change it myself. So far it has washed the coach for 2+ years and hasn't moved the needle on the TDS meter. When the time comes I can purchase another cubic foot of resin for just under a couple hundred bucks but I feel I can get quite a bit of life out of the resin so even if I have to change it every 3-4 years that is still much better than all of that drying.

Mike

 

[zmotorsports]

Sorry, this is a bit lengthy but I've been playing with some theories and spring options over the past several years in order to dial in my Jeep's on and off-road ride characteristics right down to the gnat's ass. I think I am on the right track of finding that balancing act between ride height, road manners, off-road manners and ride quality. I know that each company has suspension systems for the masses but we all have our vehicles either loaded differently or configured in some manner that makes a mass produced kit less than ideal. I also think ride quality, looks and overall off-road ability to many is somewhat subjective. So here's my thoughts on where I'm at with my Jeep JKUR.

After a few off-roading trips this year I have been thinking through a few alterations to my suspension. Back when I first built the Jeep in 2011 I had purchased a BDS 4.5" long-arm suspension system and over the years I have tweaked and modified it to resolve what I think were design flaws and to customize it to my liking. Things such as building my own links to incorporate rubber encapsulated (Clevite) style bushings and Johnny Joints vs. the BDS proprietary bushings that kept failing. Also over the years as my Jeep has gained a few pounds I have played with rear coil springs in order to chase rear ride height as well as overall ride characteristics. I replaced the BDS coils several years ago with some OME ones that rode nice but still didn't give me quite the height I was after so I added a 1" spacer to get me closer. Ride height was better but overall ride was a bit "soggy" feeling.

Next up was I added some 4.5" plus Currie over-landing rear coils. These were recommended by Currie as a direct replacement for their 4.5" suspension springs but for one that is loaded a bit heavier in the rear for over-landing. These were better but still not quite where I wanted to be. I ended up added a 1/2" spacer but again ride height was still a bit lower than I would like in the rear and with a couple people in the rear I was contacting my jounce stops over bumps.

As I have been toying over thoughts over the past six months of playing off-road as well as on pavement I determined that I wanted to try a rear spring that had not only a bit more free length but also a slightly stiffer spring rate. On the last couple of off-roading trips I noticed that when climbing a rather steep ledge or shelf that I could actually feel the weight transfer to the rear as I ascended the climb which I feel was making my Jeep lose traction at the front tires. My thinking is that if I install a rear coil spring with a stiffer spring rate it would benefit two-fold. First, it would give me that little bit of extra lift at ride height, I figured about 3/4" would be about ideal as I don't want the front end lower than the rear. I like that nose high look and feel. Secondly, I think that as I am climbing if the rear didn't compress so easily it would help keep my front end planted and maintain traction with the front tires.

My search for spring rates and free length went on for a few weeks and many phone calls as most companies don't list such specifics. Well after a long discussion with a gentleman at Metalcloak suspensions a couple of weeks ago I opted to give something a try. He thought I should use their 4.5" true dual rate springs but I informed him I haven't had the best luck with anyone's 4.5" springs as they are netting me closer to 3.25"-3.5" of net lift due to the weight. He said he has overlanding Jeeps that use them and they get more height than advertised but I again informed him that I feel mine is a bit heavier than having a tent on my roof and a refrigerator in the rear. I was not doubting his knowledge as he was very knowledgeable and obviously has more experience than I do, I just know my Jeep.

In the end I ordered a set of their 5.5" dual rate springs because I didn't want to use spacers again as I wanted to use all effective coils to accomplish what I was after.

The springs showed up on Friday so Saturday I made quite a few measurements and then swapped out the rear coil springs. I think I am on to something with a cure for pavement driving but I will have to wait until I can get off-road to test the off-pavement manners.

So far here are my results. Starting photos. Jeep with 4.5" Currie over-landing rear coil springs and a beginning measurement of 32-1/8" from bottom of wheel to rolled lip of fender flare. My goal would be in the range of 33" to max. of 33-5/8" at ride height. Also worth noting is that I am not running my hi-lift jack, Yeti cooler, lawn chairs and I have just under 1/4 tank of fuel. This will be the highest ride height I should experience.

After removing my Currie 4.5" over-landing springs you can see the free length difference between the Currie 4.5" coils and the Metalcloak 5.5" coils, much more than merely an inch. Also look at the diameter of the coils and the pitch. The Metalcloak's are about .062" thicker and the pitch is greater resulting in the slightly higher spring rate. The Currie's were 88 lbs/in and the Metalcloak's are 100 lbs./in. spring rate so not much but only slightly stiffer.

New Metalcloaks installed at droop.

New Metalcloaks installed at ride height.

Final measurement at ride height after a test drive to let everything settle is 33-3/8" so a height gain of 1-1/4". A bit more than I wanted but slightly less than my max amount. I had acquired my maximum amount by leveling the Jeep as I do not want the rear higher than the front at any time.

I also checked the angle after my test drive and I am still very slightly nose high with .4 degrees of difference front to rear, rear being ever so slightly lower.

So far I only have about 150 miles on the new rear coils but I can definitely tell a difference on the pavement. It is not harsh by any stretch of the word but it did firm up the rear end. Going over interstate bridge seams and railroad tracks at speed is where I have noticed it the most. The rear end feels much more planted with the road and hardly any undulations from the rear end. I even did some high speed cornering yesterday, well as high speed as you can in a Jeep anyways, and it is much more stable in the corners. We have a rather winding on-ramp to the freeway and upon accelerating aggressively it felt so much more stable and firm that I could push it even harder than really necessary. I really wanted to push it a bit so I could rule out just having a placebo affect with spring swap and so far there is definitely a favorable difference on the pavement. It still floats going down the interstate @ 70 MPH though so my street manners did not suffer and actually improved slightly. Now the real test will be the off-road manners.

Thanks for looking.

Mike

 

[RockChucker]

That is some good research. You have the same problem I have....nothing anyone makes is what you want....so you adapt, modify, build your own etc. In my opinion, the best thing you will be able to do to really push to the next level is crack open those Fox shocks and tune them. I'm not an expert but can tell when shocks are less than ideal. I hired out to Matt @Desert Speed Shock Tuning. Best money I have spent on my Jeep. Seriously. It rides very soft and compliant, but he reduced body roll and increased bottom out resistance over the OEM shim stack that Fox put in my coilovers. Worth every penny. In fact, he currently has the Fox IFPs off my Duramax right now. They needed a service bad, and he's going to change the valving to be better. I think Fox is really good at making a shock out of quality parts, but their valving stinks.

 

[zmotorsports]

That is some good research. You have the same problem I have....nothing anyone makes is what you want....so you adapt, modify, build your own etc. In my opinion, the best thing you will be able to do to really push to the next level is crack open those Fox shocks and tune them. I'm not an expert but can tell when shocks are less than ideal. I hired out to Matt @Desert Speed Shock Tuning. Best money I have spent on my Jeep. Seriously. It rides very soft and compliant, but he reduced body roll and increased bottom out resistance over the OEM shim stack that Fox put in my coilovers. Worth every penny. In fact, he currently has the Fox IFPs off my Duramax right now. They needed a service bad, and he's going to change the valving to be better. I think Fox is really good at making a shock out of quality parts, but their valving stinks.

Thanks for the comments about having to adapt to get what a person wants. That's what I have been unable to get through to people. Most think you merely bolt on a set of links and install a set of coils per whatever height lift you want and you're done. That very well may be IF what you have is a base starting point. It doesn't necessarily work when about everything on one's car has been modified or messaged slightly from stock.

Actually your experience with Fox shocks has been pretty much the opposite as mine. I originally had BDS, then Bilstein and now finally Fox 2.0 shocks on my JKUR and I really like the ride of my Fox shocks over the others. I've rebuilt/revalved quite a few shocks on snowmobiles, dirt bikes/ATV's and sand rails over the years to know I don't necessarily want that kind of high maintenance component on my daily driver so that is why I have stuck with coil springs and an over the counter shock. So far I have been very pleased with the ride of the shocks and feel they did a pretty good job on both compression and rebound but the soft spring rates and free length of the springs is were where I was focusing much of my attention.

Thanks for following along.

Mike

 

[zmotorsports]

An additional item I decided to address yesterday was my CB mic lanyard. Since installing my new Cobra Model 29 overhead I have been playing with mic locations when in use on the trail. When daily driving and not using the CB it’s no big deal to wrap the cord around the body and clip the mic into the holder which holds it up and out if the way. However it has been awkward figuring out an easily reachable place when on the trails.

Just prior to last months annual Ouray trip I picked up one of those retractable lanyards that truck drivers use thinking I’d give it a try. I actually really like that option with the exception that it bounces around too much. I ended up using some tie wraps to control the swinging and realized that it had too many pivot points for an off-road vehicle allowing it to swing around way too much.

Yesterday after the wife and I returned from breakfast I went out to the shop to come up with a mounting solution that would hold the body solid and just allow the mic to hand by the retractable lanyard.

I measure the hole spacing on the CB body and used the mill to drill the exact hole configuration which would allow me to mount the bracket directly to the CB.

After drilling the holes I milled a 1/2” slot which would allow the end to barely fit through. I then TIG welded the two pieces together slightly tapering at the top to firmly hold the body.

Testing the fitment prior to beadblasting and painting. There is just enough taper at the top to hold it tightly in place and no additional fasteners are required to keep the body inside the bracket. I also was able to trim the two small tabs off that are visible in this picture at the top of the body where the other pivot point was at.

Test fitting to check clearances.

Quick little tip on cutting fasteners on a vertical bandsaw. Use a small piece of metal opposite the pliers to aid in holding the fastener parallel with the table. Also feed very slow to prevent the piece from catching as it cuts through.

Fasteners trimmed and ready to touch up on the sander to square up the cut end.

Completed bracket and ready for use.

Thanks for looking.

Mike