Builds Gen IV LS/NV4500 Swap (1 Viewer)

[Well Sorted]

The exhaust looks great. Do you have a heat shield above the muffler? I think I have the same muffler (with no heat shield) and it got hot enough to start melting the carpet after five or six hours on the interstate.

My exhaust is similar...I need some extra heat protection above the muffler and where the exhaust pipe crosses by the transfer case...

I kept all the factory heat shields in place and so far everything has seemed fine. We did two solid days of driving 8-10 hours and so far the carpet has held up so I think it's okay. I didn't exactly inspect the rear floor area but the carpet looks fine. I did put my hand down on the floor near the cats multiple times and didn't feel any sort of excess heat so everything seems pretty good.

 

[Well Sorted]

What is that on the back of the tcase?

VSS?

Yep, VSS. That's the unit from Jags That Run, see Post #35 for a little more detail. I was thinking that I could come up with something on my own that would work for a little less money but in the end simplicity and time savings won out and I just ordered from them. No issues so far, it seems to work just fine.

 

[Well Sorted]

Great work on the exhaust. Would love to hear a video clip of it!

The weather has been kinda wet here lately so it took some time but I finally got a video with the exhaust sound. This is from my GoPro mounted next to the tailpipe capturing a little bit of basic startup and idle, some light load cruise, and a harder acceleration. It's not the best recording but should give you an idea how it sounds.

 

[74fj40]

That sounds great. Nice deep tone, and a little throaty. Did you do an early nv4500? With the lower first gear?

 

[Well Sorted]

That sounds great. Nice deep tone, and a little throaty. Did you do an early nv4500? With the lower first gear?

Yep, early NV4500 and AA 4:1 low range gearset in the Tcase. I haven't had it on the trails yet but really looking forward to the improved crawl ratio. Might be heading to Moab next month to give everything a good workout, should be fun!

 

[Ol Yeller]

That sounds great. Nice deep tone, and a little throaty. Did you do an early nv4500? With the lower first gear?

It does sound really good, hopefully no drone on the long trips...but it looks like the tailpipe should be out enough to deal with that.

What’s next? Time to use it!

 

[Well Sorted]

It doesn't drone at all on the highway, that was my biggest concern and I hoped that the large 70-series wouldn't be susceptible to it, glad I was proven right. I just got my rear ARB and I've got sliders coming in a few weeks, as soon as those go in it's definitely time to put it to good use!

Next up in the thread... I figured I'll show a little detail of wiring, pedal installation, etc. It's not glamorous but one of the key elements to getting it running and reliable.

 

[rover67]

Howdy,

I'm not on Mud too much lately but i popped on to see what's up and noticed the build, I like it, nice work! I like what you did with the air filter and the fuel pump. You'll be happy you did an in tank pump.

I'm not sure if you figured out the emissions part, but I was able to get mine checked out and the magic letter for the swap approval written pretty easily. You go to aircare and there is a person there that inspects the swaps and certifies it. With two cats and o2's you're close. they'll look for two more o2's (after the cats) and evap stuff. They didn't seem too concerned that I used aftermarket cats. A Gm evap cannister and vent valve is pretty cheap. They can probably me mounted anywhere. I also did a fuel tank pressure sensor but did not do the fuel level input to the computer. The computer regulates the tank pressure well and purges/vents it like it's supposed to. The person that inspected the swap only commented i needed a check engine light so i removed the silk screened words from the "choke" light and stuck on a cut sticker from a sticker place in matching font that said "engine" and hooked that up to the CEL output.

Anyhow, I'm at 367,000 miles now and I put the motor in at 212,000. It gets brutally flogged (and I mean brutally) daily and has been great after I worked out the initial bugs. New valve springs and pushrods were a great upgrade as at the tunnel headed up i-70 it likes to run about 80-85mph at 6k rpm on the mat in 3rd (4.88's, 35's) but slows down in 4th. With the NV4500 things may be different. You might also look at throwing a different OEM cam in, the truck cam really sucks, it falls on it's face at around 5-5500rpm but it has worked for me regardless. The LS1 cams (~$90 used on ebay) for example do more above 4k or so and net like 60hp increase. Below 4k you'll have torque loss of course, but that wouldn't bother me personally.. it's not much, on the order of like 20lb-ft at like 2500rpm.

The h55 has been good, but the t case likes to have the thrust washers loose oil and get hot and wear. I think the loading on the intermediate gear is pretty high under the above conditions/speeds. I've probably done the thrust washers three times now in the last 150k miles? I've also been through a few rear diffs. I went with a solid spacer this last time, we'll see if the pinion stops getting loose. Solid spacer vs. crush sleeve debate! Just kidding.

 

[Well Sorted]

Great input Marco. I'm getting ready to move out of the AirCare region so passing emissions hasn't been a priority. I'll get my collector plate this year after I move and then I'm good for 5 more years. If I have to get it past the inspectors 5 years from now I'll either convert it to legal swap (Evap, etc) or register it somewhere else.

As for the driving experience, with my stock gears and 33's I'm having no problems on the pass. Going up to the tunnel or over Vail pass I drop into 4th but at that point I can pull the grade and maintain 65 mph just fine with reasonable rpm. My engine is a 2012 LC9 build, it was factory rated at 320/335 and it might be putting out a few more with the free flowing exhaust. Some day I might consider a cam swap but so far I'm just not seeing a need yet. Interesting to hear about your H55 issues. I'm hoping the NV4500 is pretty bulletproof and with the 6.34:1 first plus my 4:1 kit it should do really well out on the trails.

Are you ever at club events or Cars and Coffee? Would like to see your rig some time, specifically interested in how you got the 35's on and your experience with them.

 

[rover67]

Ahh, i guess I didn't realize you were done already!!

The h55 has been great, i like it and the gearing a lot. I only wish for a deeper overdrive sometimes but I also did the 4.88's which puts me in the wrong direction to begin with.

The t case is what has struggled a little bit.

I go to the rising sun meetings/events though not as much as I used to. Not sure what cars and coffee is but I coudl do something and meet up sometime for sure.

Congrats on getting the rig going!

 

[theocruiser]

Subscribed! Nice work!

 

[Well Sorted]

Theo reminded me I've been very lax about updating this post. I'll try to get going again with some wiring details...

The GMPP package includes an electronic throttle pedal with a sort of universal bracket. I think they intend for this to be bolted to a flat firewall in a hot rod or something similar but there's no way to use it as delivered in the FJ60. First I stripped the installed brackets off to leave the bare pedal...

My goal was to mount this as close to the original location as possible. On top of that, I wanted a stiff bracket since there can be quite a bit of force on the pedal when you romp it to full throttle. I came up with a two piece bracket design that utilizes the original pedal mounting holes plus grabs one of the steering column mount holes. This was all done with paper templates and a little bit of careful bending in my press brake, the bracket is made from 1/8" mild steel and powdercoated. Here it is in pieces before installation:

Installing it was a bit tricky, the bracket on the steering column side had to go in first because the bolt is concealed by the pedal body. I then put the pedal in position and put the RH bracket on securing it all as a sandwich using M8 thru bolts. The two bolts which attach to the factory bracket locations went in last. Once in and tight it was nice and stiff. I adjusted the factory pedal stop down to just allow the pedal to hit WOT and act as a brace behind it. Installed views...

To connect to the GMPP harness I had to remove the plug in order to feed the wiring through a hole in the firewall. If you're going to be messing with the metripak connectors I highly recommend buying a proper tool set. These were cheap and have worked fine for me:

https://www.amazon.com/gp/product/B01NCU7MAC/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

 

[74fj40]

As always, awesome work!

 

[Well Sorted]

Getting back to the story...

So with the pedal in place the rest of the wiring is pretty straightforward plug and play connections. The GMPP harness is labeled nicely, but there's some extra length in areas that needed to be secured and general tidying up. The one area I had to do a little customization was the charging circuit. The 2012MY LC9 engines come with a smart charging alternator that uses a two wire connector. These are known as DR44 alternators in the GM/Delphi world and aren't ideal for a swap. They use a current sensor on the factory battery cable to sense the electrical load and the PCM controls the alternator output. If you try to run them without these controls in place they will default to a 13.8V output at 60% or so of capacity. Some guys seem to be making that work, but it's not ideal for an overland rig which might have a lot of electrical loads in the future. These are easy to identify by virtue of the two pin connector as you can see here:

The easy solution is to revert to the earlier alternators which use a standard 4-wire connection known as a CS144. These are on cars and trucks from the early 2000's and in stock at your local parts store. They have the same case as the DR44 alternator so it's a direct bolt-in replacement. The GMPP harness I'm using (same as on the eRod engines) has the 4-pin plug with just a single wire in it which excites the alternator by connecting to the L terminal in the plug. Here it is plugged in...

With this setup, you can start and run the engine and you'll get the full 14.4 output of the CS144 alternator which is 140 amps. If you need more than that there are many higher output versions that can be found through specialty alternator shops, I've seen many options over 200A and a few that go even higher. The only remaining challenge was to get the charge light on the dash working.

The dash charge indicator lights up when there is no charging occurring, basically when it sees ground you'll get the warning. To keep the light off, the light must be connected to the L terminal on the plug so that when the regulator is activated the charge light circuit sees the voltage. So for this application the simple solution was to just splice the Toyota factory wire in to the pre-existing wire of the GM harness that was activating the regulator. No photos for this, I just made the splice a couple inches away from the alternator and concealed it in the split loom.

With that done, the charging circuit is hooked up and everything was ready to fire up.

 

[Well Sorted]

Firing up the engine for the first time was a rewarding feeling of course. I cycled the key a few times to prime the fuel system and she fired up on the first crank, crappy cell phone video to mark the occasion...



I cut off the recording so I could check for leaks and issues as it came up to temp. Happily, there was no drama. I found a very small drip at my fuel filter connection that a quick tightening took care of. Other than that, it was just monitoring coolant levels and making sure the system burped out the air. With the steam port direct plumbed into the radiator it did a great job of self bleeding, other than a few small top offs it required really no effort to get a clean and full cooling system. Prior to the startup I picked up a bluetooth OBDII monitor to keep an eye on the engine, after a little research I chose the OBDLink MX Bluetooth unit. Having that running while the engine came up to temp was a nice way to monitor everything and see that all systems were working normally.

The grill, lights and hood were still off the truck and I hadn't worked on the clutch yet so after bringing everything up to temp I shut her back down and got on with the rest of the systems so that I could actually drive it. Bleeding the clutch was a bit of a pain, it's not uncommon to have these things take time when the system is dry. I use a vacuum pump setup to speed things along some, but getting those last bubbles out always takes time. In this case, there are also numerous adjustment points to be dealt with. The slave cylinder mounts at the rear on an adjustable heim (see Post 43) so between that and the front connection to the clutch fork you can play around with the pre-tension. There's also adjustment in the pedal under the dash so between the three locations it took a bit of fiddling to get the clutch to engage fully. It works with the factory clutch master, but a little bigger bore diameter sure wouldn't hurt.

Installing the front end meant I got to put in some of the fun upgrades I had purchased. First was the Rigid LED lights, p/n 55008. These bad boys aren't cheap, but the combo of LED lighting and a heated lens is amazing. I talked myself into it with the argument that I wouldn't need auxiliary lights if I ran these and so far that's been true. The heated lens is critical here in CO because this rig is my ski wagon and we spend a lot of time headed up into the mountains in the storms. These are also plug and play, so install is no more difficult than changing a bulb.

The second big upgrade was a 4-Plus baja style front bumper. I know the ARB is a classic look on these trucks but I really like the more streamlined design of the baja bumper. Dave at 4-Plus was super helpful and easy to work with, this particular unit is raised 1" to help conceal the body lift and I am extremely happy with the quality of work. Rather than go black I chose to get it in raw steel and paint it myself. I'm testing out a dark gray color that I found in a Rust-Oleum can. My goal was to match the trim color in the headlight surrounds, this is a bit lighter but got me close enough for evaluation purposes. Once I finalize my color choice I'll probably pull it off again and get it powder coated or sprayed with colored Line-X.

 

[skidooman]

Man, this thing is BA. I knew from the outside it would be clean, but I had no idea. Keep up the good work!!

 

[cruiser enthuiser]

Yeah totally nice job on your conversion and some great tech here! Keep us posted!


-Ed

 

[Elbert]

looking good.

 

[Well Sorted]

With the front end back on I went out for the first test drive late one evening. All in all it went just as you'd hope - great sounds, great power, no leaks or issues. It was uneventful in a good way and I couldn't wipe the big grin off my face. These trucks are sooooo much nicer to drive with 200 more horsepower on tap. I cruised it around town a bit and checked for leaks but all was well. That weekend my wife and I went skiing so the first real test was the drive up I-70 to Summit County where all the ski resorts are. In case you're not familiar, the highway runs west out of Denver up into the mountains and tops out at Loveland Pass where the continental divide is. If you take state highway 6 you go over the top of the mountains and reach a peak altitude of 11,990 feet. Getting there with a 2F is a slow affair, the uphill grades are often 6% and it's a dance between 2nd and 3rd gear. With the LS I was able to hold 70 up the grades mostly in 5th and dropping to 4th in the steeper sections. Of course, I had to take the hero shot at the top...

The truck ran well most of the weekend but Saturday night I had my one and only real issue. We pulled into the parking lot at the ski shop to get a few things and as I jumped back in to leave I pushed in the clutch and heard a pop and "sproing" sound immediately followed by no actuation. Thankfully the pavement was clean and dry and the lot was well lit, I slid under the truck and found that the slave cylinder had come loose at the rear mount and was hanging free. The heim was still on the mount and it appeared that it had just unthreaded itself. I had tools with me so it didn't take too much to thread the heim back in and tighten everything up. In hindsight, I realized I should have seen that coming because I was noticing that the shifting was getting notchy just prior to it. As the cylinder loosened I was not getting full disengagement of the clutch so that little bit of drag was causing the shifting efforts to be high. 15 minutes later we were back on the road though, and all was well for the rest of the weekend. I think I must have just not tightened the rear jam nut the last time I adjusted everything because it's been absolutely fine since then.

 

[Well Sorted]

With a few miles on the odometer we went right in to a big test. We had plans to spend the holidays in Atlanta with the family then fly out from there for our honeymoon so we loaded up the truck and set off for Georgia. Mother nature wasn't cooperating, we departed Colorado on a snowy day and headed east into the plains. Temps were single digits with some serious winds blowing. I had my fingers crossed for no more mechanical issues, definitely didn't want to be doing roadside repairs in those conditions.

Thankfully, all went well on the cross country trip. 1500 miles later and we arrived in Atlanta without any issues. We did learn that the doors weren't sealing as well as we'd like and there are serious air leaks around the door handles when there are crosswinds. One day while in Atlanta I pulled the door panels and lined everything with dynamat in an effort to cut down on the road noise and air leakage. The biggest complaint though was the noise from the 4:1 gears radiating up through the twin sticks. Wrapping a jacket around the shift handles cuts it down a lot, otherwise it get's pretty grating to hear that high frequency whine for hours on end. I still use the jacket trick any time I'm driving on the interstate for an extended time.

We also encountered a lot of snow and road salt. The pristine undercarriage now was covered in grime and corrosion appeared on all the little exposed areas without good anti-corrosion coatings or paint. My biggest disappointment in this area has been that the Hooker manifolds I purchased (coated, by the way) were starting to rust. Whatever coating they use is not able to handle winter driving conditions. I sent this photo to Hooker and asked them for feedback...

The rep I spoke to essentially said that while they're coated they don't guarantee them against corrosion and he's not surprised to see that after exposure to road salt. I questioned what the point of it all was then and he said something like their coating keeps it from flash rusting, but isn't a deep coating. No warranty for me. I called Jet Hot and sent them this image, they said their coatings would be impervious to road salt and they'd guarantee them. Only problem is that they want $450 for the coating and I've got to pull the truck apart to do it. No bueno. For now I just scrubbed them down with a scotch brite pad and let it be. The scotch brite knocked off the really ugly red stuff and they're not really getting any worse so I'm just living with it. If I had to do it over again I would either get these properly coated or maybe buy the stainless manifolds.

After our visit we loaded up and headed back home. The drive back was once again uneventful. The dynamat inside the doors helped to quiet things a bit and certainly cut down the air leakage. Conditions were much better for this run, though there was one foggy morning in west Kansas that was interesting. Anyone read Steven King's story The Mist?

No strange creatures emerged though, and we made it back to Colorado. Gratuitous state line shot...

This is also the segue to the next project. The rear bumper is one I ordered from @reevesci and quickly threw on before the trip. You'll notice that it's got no ends and the swings aren't on it yet. Jason customized it a bit to account for the 1" body lift but didn't want to put rocker protection on, evidently there's too much variance in fit between trucks to do it without a custom fitting. I had him deliver it without sides and am making my own rocker guards. Details to come soon...