Trifecta Build Thread - KOH EMC, Cruise Moab, Rubithon

[Charles4x4]

Two weeks ago it hit me - Now is the time when most teams begin dreaming about and working on their 2019 KOH builds. Over the past few weeks, like many of you, I watched most of the 2018 KOH / KOH EMC coverage. And, like many of you, wished I was there. So, I've decided to do something about it.

My first thought was...we'll...hold that thought for now.

My second thought was honestly of the millions of reasons why it wouldn't work out:
- I have a day job, an amazing wife, and two awesome girls who all keep me busy
- I have a budget, but certainly not enough savings for all I'm going to need to buy
- I have no crew, no sponsors, and no vehicle to start with
- Other than Moab EJS 7-years ago, my 30th birthday present from my wife pre-kids, I've never wheeled on the West Coast and certainly have never competed in anything like KOH
- I am scared I'm going to roll while coming down Back Door There is no easy line!

But, more importantly, my first thought was...I CAN DO THIS:
- I believe that God gave me the gifts of being a creator, builder, and engineer who loves to learn new things and can envision the possible
- I have never backed down from a challenge. I am determined, passionate, resourceful, and love to work hard - I always finish what I start.
- I have never taken the conventional route and it has always led me to amazing experiences - why start now?
- I love offroading and vehicle fabrication. I can see the lines at high speed and envision unconventional lines in the rocks. I love staring at a vehicle and imagining what it can become. I'm not extremely experienced at either, but I desire to get better at both.
- I believe life is a collection of experiences. The most amazing ones typically require a difficult choice at the beginning - should I try this crazy thing? The hardest part is always the same - Starting.

So, this is me Starting. What is my plan? Let's find out...

 

[Charles4x4]

Like most of you, I'm a Toyota guy through and through. I have an 80 series, a 100 series, and a 1st gen 4Runner I restored to mint condition that is currently for sale. I also built and sold another 1st gen 4Runner 6-months ago as well.

I have also spent enough time and research to know that a skillful combination of driver skill and vehicle strength, reliability, and elegant simplicity are keys to success.

So, simply put, it'll be a Toyota 4Runner.

What about the Trifecta? My personal hobby-based bucket list is simple - create a Toyota that can do all of the following well:
1) Compete in KOH EMC with a goal of both Starting and Finishing, not Winning
2) Take the family back to Moab, this time at Cruise Moab and do Pritchett Canyon
3) Take the family to Rubithon and complete the multi-day Rubicon Trail experience

And, I'll add, I want a vehicle that I wouldn't be embarrassed to take the family to church in or to grab ice cream on a hot summer night.

The reality is that #2-3 above severly limit my ability to stand on the podium at KOH EMC, and I'm completely fine with that. I want to build something that does a lot of things well.

Out of all the Toyota vehicle options, my favorite for this is the 4Runner. Here's why:
- Light, yet strong
- The stock engines have decent power and are reliable
- I love its timeless looks
- It has a great wheelbase and 4-doors with plenty of room for when the family is with me
- It is refined, yet highly affordable as a base vehicle

A 40 series would be nice for Moab and KOH, but they’re expensive to start and would be cramped with the kids and gear for Rubithon. I'd love to use a 60 or 80 series for Moab, but feel they are simply too big and heavy for KOH. I think a 1st Gen 4Runner fits the bill nicely, but am worried about strength in a few areas (frame/electrical) and while I love the 22RTE for reliability, power is certainly lacking for the desert without an engine swap that is currently not in the budget.

So, what's left? You might have guessed - I'm leaning heavily toward a 3rd Gen or 4th Gen 4Runner that I can "modify".

 

[Charles4x4]

So here are the options I'm considering:

Option 1: Compete in the KOH EMC 4500 Modified Class (Stock frame from engine mounts to behind front seat, no full-hydro steering, two shocks per wheel (not counting air bumps) with 14" limit on coilovers, and 37s)

Vehicle: '99-02 Toyota 4Runner (3rd Gen)
Engine: Stock 3.4L v6 with TRD Supercharger
Transmission: Stock - will it hold up? I'm not a Tranny expert!
Transfer Case: Atlas 2 or Marlin Dual Case (Strength & Value are a priority)
Axles: Diamond or Dana 60's at both ends, 14 Bolt Rear/Dana 60 Front, or 80 Series Axles on both ends (high-steer front and rear offset are an issue) - 4.88 or 5.29 Gears with Selectable Lockers of course
Tires: I already have four 37x12.50r17 Cooper STT Pro's in the basement that I love. Would need to get 3 more for spares.
Wheels: 17" Beadlocks - brand TBD. Would need 7 total ($$$)
Spare Tire: Likely mounted in the bed at the rear behind the fuel cell
Suspension: 3-Link Front and 4-Link Rear; 14" Coilovers F/R with Remote Reservoir and dual shocks up front
Driveshafts: Custom TBD
Fuel Cell: Aluminum mounted in the bed to make room for rear 4-Link without Panhard Bar and distribute weight (battery in rear too)
Sway Bars: F/R Currie Antirock or TBD
Steering: Mechanical High steer with PSC Hydraulic Assist
Armor: F/R bumpers, sliders, full skid plates, steering guard
Winch: Warn
Safety: Full Roll Cage and all the required safety equipment for KOH (5-point harnesses, racing seats, kill switch, catch pans, etc)

I know I'll need a T-100 2wd oil pan given SAS and hope the fuel cell would give me enough room to house the rear 4-link comfortably. I'd use junkyard skins to create half-doors for KOH (save weight and no worry about dents), but retain the timeless 4-runner look/feel. For the body, I plan to cut portions of the roof and bob the bed 12" or so. This should save weight and add the "topless cool factor" for the girls while on the trail.

But overall, I want it to look and feel like a 4Runner. I don't know about all of you, but most today's KOH EMC 4500 rigs look like buggies, which I do agree is a necessity if you are competing to win. I want to compete and finish, but do so in a vehicle that looks like a 4Runner - retaining what I believe was the original essence of the "Every Man Challenge".

I also want to keep the rear seats for the family (removed for KOH to save weight) and all 4 doors (swapped out with half-door skins for KOH). Then I'll have a soft top made so we can keep warm/cool/dry on the trail. Overall, think the functionality and weight of a Jeep with the strength/reliability of a Toyota.

 

[Charles4x4]

Option 2: Compete in the KOH EMC 4600 Stock Class (Essentially a "Driver's Class" in vehicles the heavily resemble "Stock Condition" - too many restrictions to list)

Vehicle: '05-09 Toyota 4Runner Sport (4th Gen)
Engine: Stock v8 with possible Performance Modifications
Transmission: Stock - will it hold up? I'm not a Tranny expert!
Transfer Case: Atlas 2
Front Suspension: IFS Long Travel Arms, 12-14" Dual Rate Coilovers with Remote Resevoir, heavy duty Steering Rack (reinforced Tundra rack?), Stronger Front Diff, 4.88 Gears and ARB Locker, Chromoly CV Shafts, big Heim Joints and Ball Joints at all corners, reinforced control arm mounts.
Rear Suspension: Long Travel 4-link with coils and high-performance shocks (coils are a requirement - no coilovers allow in the rear, but linkage can be changed in any way needed)
Tires: 7 or so of the Largest 35's (max tire size) that I can find.
Wheels: 17" Beadlocks - brand TBD. Would need 7 total ($$$)
Spare Tire: Likely mounted in the bed at the rear behind the fuel cell
Driveshafts: Custom TBD
Fuel Cell: Aluminum mounted in the bed to distribute weight and make room for the rear 4-link
Battery: Mounted in the bed to distribute weight
Sway Bars: F/R Currie Antirock (Front Sway Bar needed on IFS?)
Armor: F/R bumpers, sliders, full skid plates, steering guard
Winch: Warn
Safety: Full Roll Cage and all the required safety equipment for KOH (5-point harnesses, racing seats, kill switch, catch pans, etc)

 

[Charles4x4]

So here is my quick break-down:

Option 1: 3rd Gen 4Runner in 4500 Modified Class

Pros:
- SAS has historically been more reliable in the rocks
- 3rd Gen is light with a decent wheelbase (105")
- Supercharged v6 is reliable
- Body modification permitted, so I can make it feel "topless"
- Can do Coilovers, Bypass Shocks, and Air Bumps per corner
- Can recess Fuel Cell into the bed between the frame rails to low Center of Gravity
- Can run 37s

Cons:
- SAS will be slower in the desert
- Supercharged v6 is way under powered for this class (think 6.2L Hemi)
- Will be cool, but not "Revolutionary"


Option 2: 4th Gen 4Runner in 4600 Stock Class

Pros:
- IFS will dominate the desert in this class
- 4th Gen is still light and has a great wheelbase (109")
- V8 has plenty of power (270 HP / 330 Torque) and can be modified
- Will be one of the first IFS cars to compete in the 4600 class
- Will get a lot of attention

Cons:
- Can the IFS be built strong enough to handle the rocks in the Hammers
- Will the front diff and steering hold up to desert and rocks
- I cannot touch the Exterior or Interior sheet metal, so I cannot cut a lot of weight (can do half-doors and no glass) and no "Topless" cool factor
- Coilovers only in the front, Coils in the rear, One Performance Shock per wheel, no Air Bumps
- Can only run 35s in KOH
- How well will IFS Front do in Moab (Pritchett Canyon, etc) and on the Rubicon Trail?

Note I'd likely run 37s for everything except KOH EMC, so the setup would need to be capable of supporting 37s.

 

[Charles4x4]

So that is where I stand today. I've got a vacant garage bay, tons of tools, an Ultra4 Rulebook (v4.4), a vision, determination, and a supportive family. If, as they say, the only way to climb a mountain is one step at a time, my first step is selling my mint condition 1st Gen 4Runner SR5 Turbo to fund my starting budget.

Then chose an option, find the perfect 4runner to serve as my baseline, recruit a few friends to help, maybe land some sponsors, and get it done.

I've got a ton of other ideas as well, but probably more questions than anything...

 

[Charles4x4]

Here are a few of the High $ IFS 4400 cars that I've been studying. Note that of the top 4 spots for KOH 4400, 2 were IFS and 2 were Solid Axle so the jury is still out.

 

[rickashay]

Love the the background, the challenge, and the thought process. Definitely subscribed.

Nothing good ever comes easy and without risk. Props for taking the plunge!

EDIT - how about a FS link to the 1st Gen 4Runner to hopefully help find you a buyer and get you on your way??

 

[Inv4drZm]

For now I might be able to answer some of your questions and provide some of my opinion. Do you know how to weld, or have a good buddy that does? Give this project to a shop and it will be twice the money and take twice as long but it will be done right.

As much as I would love to see a V8 4Runner built to the nines, why not start with a 2nd gen Tacoma? Easy rear fiberglass fenders and mounting of 14" travel shocks/coilovers in the rear. The bed would be a great starting point to mount spare tires and a fuel cell. In my mind it makes for a better platform than an SUV. But the SUV has a "cool factor" not many people have jumped down the rabbit hole with.

Link to fiberglass fender options.

My thoughts on IFS vs solid front axle:
I think for open desert wheeling the Solo Motorsports XLT kit you have listed is an excellent bet but you will always have CV's, and if you upgrade those, the front 8" diff will be next. I think some offroad race trucks use a ford 9" center section, it might be possible to install one of those. The problem I have with the IFS long travel is that the more travel you want, the wider it gets, which I'm guessing that +4.5" kit would be a nightmare in Moab or the Rubicon in certain situations. I would bank on using a solid front axle instead. Inherit axle/gear/steering strength, ton of travel, narrow, and easy to install compared to rebuilding an entire comparable narrowed bulletproof IFS system from scratch. Not as great high-speed but you have a relatively short wheelbase to work with anyway. I would love to see a Tundra rack in our trucks though, 35-37's is pushing it steering-wise in the rocks and I've thought about upgrading to the Tundra rack myself if it was possible.

Rear Suspension:
If you want a ton of rear wheel travel coilovers will be needed. The longest off-the-shelf coil springs (Metaltech LT and Dobinson) will fall out above a 14"-16" travel shock (depends on the uptravel/droop ratio). Check out Coil Spring Specialties, they can build you whatever spring you want if you need more length. In my mind you don't need a ton of wheel travel in the rocks if you have lockers and only 35-37's. A 12"-14" travel shock is plenty. Get a rear axle that is wider on each side by 2" or so, raise the top of the shock mounts to fit inside the wheel well, notch the frame a bit, and put in the longest 2.5" shock you can keeping in mind its compressed length. Nobody makes an off-the-shelf 4-link kit for our trucks specifically, though it is easily doable once you move the factory gas tank. I've be planning on doing just this and going with a double-triangulated 4-link rear. Check out the 4-link and 3-link excel suspension calculators online to get rough estimates on where to mount links. Crazy rabbit hole for you there.

As far as engine mods:
If you can't do forced induction don't even worry about doing anything else other than exhaust for sound/belly clearance. You won't net much with the basic CAI and could loose low-end torque. Too much work for little gains, too many other things to do. Reliability is the #1 goal. Increasing horsepower and changing OEM engine components works too much against you.

All I got for now... Let me know if you have any questions for me.

 

[Charles4x4]

Love the the background, the challenge, and the thought process. Definitely subscribed.

Nothing good ever comes easy and without risk. Props for taking the plunge!

EDIT - how about a FS link to the 1st Gen 4Runner to hopefully help find you a buyer and get you on your way??

Thanks! And great idea on the link:

http://www.toyota-4runner.org/sale-...rbo-low-miles-gray-$19-990-birmingham-al.html

Hopefully I find the right buyers soon!

 

[Charles4x4]

For those not familiar with the KOH EMC 4600 class, here are the restrictions (per Rule Book v4.4) in addition to stanard safety, conduct, and other restrictions applying to all classes:

4600 Stock Class Restrictions (Summarized):

Body:
- Complete Unmodified stock frame
- Complete stock body (can cut holes for roll cage and rocker panel protection)
- Half doors are acceptable but must open and close
- Stock glass not required
- Front/Rear inner fenders must be complete
- Fenders can be trimmed to no more than 2" gap from tire at full compression
- No more than 1" body lift
- Factory Headlights are required
- Aftermarket bumpers are fine or can be eliminated

DriveTrain:
- Stock engine (no forced induction) required but performance mods allowed
- Stock transmission required
- Any transfer case is permitted
- Any axles are permitted
- Any driveshafts are permitted
- Mechanical steering required but hydro assist okay

Suspension:
- Wheelbase cannot be lengthened more than 3"
- Suspension configuration must remain consistent from stock (leafs must stay leafs, coils must stay coils, coilovers must remain coilovers) and no fancy leaf configurations (quarter eliptical not allowed)
- Suspension linkage can be changed in any configuration
- 1 shock per tire/wheel at max of 2.65" diameter and 14" stroke with no air bumps allowed
- No bypass shocks and shocks must connect axle to chassis

Other:
- Max 35" tire

-------------------------------------------------------------------------------------------------------------------------------------------

The 4500 Modified Class has much fewer restrictions (and is therefore much more competitive):

4500 Modified Class Restrictions (Summarized):
- Must look somewhat like a OEM production vehicle of some kind
- Stock frame from engine mounts to behind front seat must be retained
- Mechanical steering required but can have hydro assist (no full-hydro)
- 2 shocks per tire/wheel at max of 2.65" diameter and 14" stroke with air bumps allowed in this class
- Max 37" tire

 

[Charles4x4]

For now I might be able to answer some of your questions and provide some of my opinion. Do you know how to weld, or have a good buddy that does? Give this project to a shop and it will be twice the money and take twice as long but it will be done right.

Yes, I plan to do most of the work myself. The exception may be the cage since it is a life safety component and not a risk I'm willing to take. I'm not the best fabricator, but can weld (and I expect this project to make me much better) and have friends who are much better than I am. Also, Blue Torch Fab Works is right down the street if I need to outsource specific items like the roll cage.

As much as I would love to see a V8 4Runner built to the nines, why not start with a 2nd gen Tacoma? Easy rear fiberglass fenders and mounting of 14" travel shocks/coilovers in the rear. The bed would be a great starting point to mount spare tires and a fuel cell. In my mind it makes for a better platform than an SUV. But the SUV has a "cool factor" not many people have jumped down the rabbit hole with.

Thanks, I really appreciate your opinion. On the Tacoma, both the lack of a v8 and the fact that I'd be locked into leaf springs in the rear turn me off it and lead me back to the 4Runner. In addition to the perceived lack of room on the Tacoma platform for the family inside vs. the 4runner (I had a 2011 Tacoma and it always felt cramped in the back).

My thoughts on IFS vs solid front axle:
I think for open desert wheeling the Solo Motorsports XLT kit you have listed is an excellent bet but you will always have CV's, and if you upgrade those, the front 8" diff will be next. I think some offroad race trucks use a ford 9" center section, it might be possible to install one of those. The problem I have with the IFS long travel is that the more travel you want, the wider it gets, which I'm guessing that +4.5" kit would be a nightmare in Moab or the Rubicon in certain situations. I would bank on using a solid front axle instead. Inherit axle/gear/steering strength, ton of travel, narrow, and easy to install compared to rebuilding an entire comparable narrowed bulletproof IFS system from scratch. Not as great high-speed but you have a relatively short wheelbase to work with anyway. I would love to see a Tundra rack in our trucks though, 35-37's is pushing it steering-wise in the rocks and I've thought about upgrading to the Tundra rack myself if it was possible.

On IFS vs. SFA, a year or two ago I would have agreed with you completely. I'm not sure if you watched KOH this year, but IFS cars are beating SFA rigs throughout the Hammers in addition to the desert. I'd argue the Hammers are certainly harder than anything at Moab or Rubicon. Think about it, if built right and strong, they have a lower center of gravity, tons of travel per wheel independently without SFA body roll, and the IFS technology strength has grown so much that they aren't breaking any more frequently than the SFA rigs. It has really surprised me.

On the CVs: Note that the Solo XLT kit comes with upgraded Currie D44 equivalent chromoly CVs, so they should be plenty strong. The diff is my my main concern, but maybe a Tundra, Sequoia, or 200 Series diff would be stronger?

On the other hand, most of the 4400 KOH cars are Rear or Center engine mounted, not Front Engine allowing the IFS front to stay light and "flow" over obstacles. And the level of fabrication in a 4400 car is both stronger and much more $$$ than a Solo XLT kit combined with chromoly CVs, a larger diff, and a tundra steering rack. Can it hold up - I don't know if anyone knows?

As a side note, Solo regularly modifies Tundra rack to fit 4th gen 4Runners so give them a call. You ship them a used steering rack and they ship it back after modifying to fit.

Rear Suspension:
If you want a ton of rear wheel travel coilovers will be needed. The longest off-the-shelf coil springs (Metaltech LT and Dobinson) will fall out above a 14"-16" travel shock (depends on the uptravel/droop ratio). Check out Coil Spring Specialties, they can build you whatever spring you want if you need more length. In my mind you don't need a ton of wheel travel in the rocks if you have lockers and only 35-37's. A 12"-14" travel shock is plenty. Get a rear axle that is wider on each side by 2" or so, raise the top of the shock mounts to fit inside the wheel well, notch the frame a bit, and put in the longest 2.5" shock you can keeping in mind its compressed length.

See above - per 4600 class regulations, I have to stick with coils and a link configuration for the rear if I go with the 4th gen 4runner. However, a 14" Coil Spring from Metaltech LT, Dobinson, or Coil Spring Specialties paired with a 14" high performance 2.5" shock should work fine - preferably if it is somehow made dual rate.

How much wider and stronger would a Tundra, Sequoia, or 80/100/200 Series rear axle be over stock 4th gen?

Nobody makes an off-the-shelf 4-link kit for our trucks specifically, though it is easily doable once you move the factory gas tank. I've be planning on doing just this and going with a double-triangulated 4-link rear. Check out the 4-link and 3-link excel suspension calculators online to get rough estimates on where to mount links. Crazy rabbit hole for you there.

I will definitely be swapping the stock tank for a fuel cell (mandatory per KOH), so a 4-link rear is the way to go. Before I use a link calculator and fab one up myself, what are the guys running Solo/Total Chaos doing in the rear? I've seen what looks like aftermarket links, coils, and shocks on those rigs that I'd simply need to lengthen for a long-travel 4-link in the rear?

As far as engine mods:
If you can't do forced induction don't even worry about doing anything else other than exhaust for sound/belly clearance. You won't net much with the basic CAI and could loose low-end torque. Too much work for little gains, too many other things to do. Reliability is the #1 goal. Increasing horsepower and changing OEM engine components works too much against you.

Great to know. I'll spend my $ elsewhere and agree with the Reliability aspect. That's honestly what intrigues me most about the 4600 class. Unless you are an amazing fabricator (like this is your day job), it's hard to match the reliability of OEM factory made stuff. The 4400 cars have world class fabricators working on them. I won't have that luxury, so the more I can keep parts at Toyota Factory Reliability while adding strength, functionality, and speed, the better.

 

[Inv4drZm]

Yes, I plan to do most of the work myself. The exception may be the cage since it is a life safety component and not a risk I'm willing to take. I'm not the best fabricator, but can weld (and I expect this project to make me much better) and have friends who are much better than I am. Also, Blue Torch Fab Works is right down the street if I need to outsource specific items like the roll cage.



Thanks, I really appreciate your opinion. On the Tacoma, both the lack of a v8 and the fact that I'd be locked into leaf springs in the rear turn me off it and lead me back to the 4Runner. In addition to the perceived lack of room on the Tacoma platform for the family inside vs. the 4runner (I had a 2011 Tacoma and it always felt cramped in the back).



On IFS vs. SFA, a year or two ago I would have agreed with you completely. I'm not sure if you watched KOH this year, but IFS cars are beating SFA rigs throughout the Hammers in addition to the desert. I'd argue the Hammers are certainly harder than anything at Moab or Rubicon. Think about it, if built right and strong, they have a lower center of gravity, tons of travel per wheel independently without SFA body roll, and the IFS technology strength has grown so much that they aren't breaking any more frequently than the SFA rigs. It has really surprised me.........

More of my rambling, hopefully some question-answering in here:

I hear you on the IFS argument, I just think the 9" wider IFS front end will kill you in the rocks/trees on the Rubicon and Moab. So if you wanted to stay IFS with more than 14" of travel and go narrower you would need to fabricate control arm mounts further inward which I haven't seen yet on a 4wd. Not that it can't be done just offhand it seems more expensive to make as strong as a solid front. Currie makes a Ford 9" IFS housing which could be used but custom CV's would then need to be made. Tundras use 9" gears in the front as well.

Here is the Total Chaos tacoma they built to race with, and they have a couple videos on youtube. 2WD but pretty cool still.

Another video showing a caged Tacoma being built at Camburg.

My twin brother and I (mostly him) have been researching rear diffs and he recently ordered a LC 9.5" rear diff for his FJ. Most of my knowledge stems from him, but contact any of these manufacturers and they will be able to tell you way more than I. Use this as a starting point.
The land cruiser 9.5" ring and pinion is basically the same strength as the Ford 9" r&p that is common to use in offroad race trucks. Currie can build you a Ford 9" or high pinion D60 rear diffs with Toyota hubs. Both of the low pinion LC 9.5" and Ford 9" options are stronger than a high pinion Dana 60 and both the 9.5"
and 9" use a dropout style 3rd member making for easy gear and oil changes. JustDifferentials.com and Front Range Offroad can build you a 9.5"/10.5"/Ford9" with Toyota hubs (JustDiffs might just use the LC 9.5" not sure). You don't need the link bracketry so you can leave those off when you order it, and I'm guessing you will be wanting compatible hubs so ABS/VSC works properly. You can get axles built semi-float (stock design) or full-float which gains you larger axle shafts and easy axle shaft swaps if you do break one. Made to order any width you want. The Tundra 10.5" is equivalent to a 14 bolt rear diff, so both are stronger than a Dana 60. Contact Just Diffs or Front Range Offroad for price quotes between 9.5"/10.5"/Ford9" and Full Float/Semi for each. If you are looking to pick up a diff from a junkyard, stock housing LC 9.5" have offset 3rd members, not sure how ideal that would be for driveline routing, you will need a custom driveshaft at minimum I think. Not sure if the wheel speed sensors work with our trucks either.

For rear suspension, its difficult to get it to keep up with the front once you go LT front, I have heard. You will want to mount the rear shocks as high in the wheel well as possible to get the most travel out of the rear. A wider rear diff will help.

FJ example

3rd Gen 4Runner Example

Solo Motorsports can do that with the steering rack? Had no idea, sweet...

 

[Charles4x4]

I hear you on the IFS argument, I just think the 9" wider IFS front end will kill you in the rocks/trees on the Rubicon and Moab. So if you wanted to stay IFS with more than 14" of travel and go narrower you would need to fabricate control arm mounts further inward[/URL] which I haven't seen yet on a 4wd. Not that it can't be done just offhand it seems more expensive to make as strong as a solid front.

I get it - and it's a really good point. On the width, is this math right?
4th Gen Axle Width WMS: 65"
Solo: + 9" = 74"
Total Chaos: +7" = 72"

FJ80 Rear Axle WMS: 63"
D60 WMS: 67-69"

Is this right? A 72-74" WMS does scare me for trails! Never imagined it'd be wider than a D60. Also never would have guessed a 4th Gen axle is wider than a FJ80 axle. Maybe my 4th gen WMS research is wrong?

Currie makes a Ford 9" IFS housing which could be used but custom CV's would then need to be made. Tundras use 9" gears in the front as well.

Yeah, the Currie F9 is awesome but really expensive ($5K just for the diff) and I'm not sure if it will fit in the stock diff location.

My twin brother and I (mostly him) have been researching rear diffs and he recently ordered a LC 9.5" rear diff for his FJ. Most of my knowledge stems from him, but contact any of these manufacturers and they will be able to tell you way more than I. Use this as a starting point.
The land cruiser 9.5" ring and pinion is basically the same strength as the Ford 9" r&p that is common to use in offroad race trucks. can build you a Ford 9" or high pinion D60 rear diffs with Toyota hubs. Both of the low pinion LC 9.5" and Ford 9" options are stronger than a high pinion Dana 60 and both the 9.5" and 9" use a dropout style 3rd member making for easy gear and oil changes. JustDifferentials.com and Front Range Offroad can build you a 9.5"/10.5"/Ford9" with Toyota hubs (JustDiffs might just use the LC 9.5" not sure). You don't need the link bracketry so you can leave those off when you order it, and I'm guessing you will be wanting compatible hubs so ABS/VSC works properly. You can get axles built semi-float (stock design) or full-float which gains you larger axle shafts and easy axle shaft swaps if you do break one. Made to order any width you want. The Tundra 10.5" is equivalent to a 14 bolt rear diff, so both are stronger than a Dana 60. Contact Just Diffs or Front Range Offroad for price quotes between 9.5"/10.5"/Ford9" and Full Float/Semi for each. If you are looking to pick up a diff from a junkyard, stock housing LC 9.5" have offset 3rd members, not sure how ideal that would be for driveline routing, you will need a custom driveshaft at minimum I think. Not sure if the wheel speed sensors work with our trucks either.

The 80 series 9.5" is ideal for strength and cost, but the offset worries me at speed. I have an 80 series locked on 37s now that I drive daily and agree that it's hard to beat those axles.

I need to give the groups above a call and see how much a LC9.5" with Toyota Hubs will run.

For rear suspension, its difficult to get it to keep up with the front once you go LT front, I have heard. You will want to mount the rear shocks as high in the wheel well as possible to get the most travel out of the rear. A wider rear diff will help.

Per 4600 rules, I don't think shocks can go in the wheel wells. But I can still mount them as high as possible under the cab.

Also, I did some research on CVs. RCVs are expensive, but look extremely strong. Not sure what Toyota diffs they would fit, but I assume they can fit almost anything:
http://www.rcvperformance.com/category-ultimate-ifs-axles.aspx

I'm guessing they would be quite a bit stronger than the Currie ones from Solo, but are probably more expensive:
https://www.solomotorsports.com/sho...wertrain/toyota-4wd-4340-custom-axle-package/

Overall, I really like the idea of IFS. But, here are my biggest concerns:
- Overall cost vs. a 3rd gen SAS
- Overall width needed to hit 14-19" of Travel (good for desert, but too wide for trails)
- Front diff strength vs. cost (maybe a Tundra, Sequoia, 100/200 series diff is an option - not sure if they will fit)
- Rear suspension is likely a custom fab 4-link

But I do think we've solved:
- The steering rack (modified Tundra via Solo)
- Rear axle options seem to be there (LC 9.5" with Toyota Hubs - around $5K)
- And suspension strength seems to be decent with either Solo or Total Chaos

Not surprisingly, it's hard to build a Trifecta type rig. They are either good in the desert (no trees) or in the rocks (no high speed), which is what makes this challenge so fun to tackle and exactly what makes KOH such a challenging, unique race.

 

[Charles4x4]

While I like the idea of going all out, all this research has forced me to wonder how well a more moderately modified 4th gen would do for the Trifecta type build:

Consider This Option:
- '05+ 4th Gen V8 4runner Sport
- Moderate Long Travel Kit (11-13" of Travel with 4" or so track width increase), 8-10" coilovers with RR, and various UCA/LCA mount reinforcements as needed: Solo or Total Chaos
- Stock front diff with 4340 Chromoly axle shafts (4.88 gears and ARB Locker)
- Modified Tundra steering rack
- Stock rear diff with Chromoly axle shafts (4.88 gears and ARB Locker)
- 35's on 17" beadlocks and Fiberglass front fenders
- Rear link system, coils, and RR shocks (Total Chaos has a rear link system shown here)
- Stock transfer case or Atlas II
- Roll cage, racing seats, bumpers, winch, sliders, skid plates, and other safety stuff as needed for KOH

It would be significantly less $ and time, probably a ton of fun to race, and I can always upgrade as needed once I break something. It certainly wouldn't win, but who cares. My goal is to survive. Think it would survive?

I ran a quick budget and it's around $30K, not including the vehicle.

Thoughts?

 

[Volcom]

On IFS vs. SFA, a year or two ago I would have agreed with you completely. I'm not sure if you watched KOH this year, but IFS cars are beating SFA rigs throughout the Hammers in addition to the desert. I'd argue the Hammers are certainly harder than anything at Moab or Rubicon. Think about it, if built right and strong, they have a lower center of gravity, tons of travel per wheel independently without SFA body roll, and the IFS technology strength has grown so much that they aren't breaking any more frequently than the SFA rigs. It has really surprised me.

The IFS the Ultra4 racecars are running vs the IFS you can get for any of your Toyota choices are completely night and day different. They are running trophy truck Currie front diffs and massive (f'ing MASSIVE) front CV's and A arms. Probably $30-40K in front end components alone. Your normal Toyota rack and pinon steering systems will fail in the rocks. Solid axles hold up way better than off the shelf IFS systems. You might be a little slower in the desert but at least you'll get a shot in the rocks with a solid axle.

I've been to KOH the last two out of the three races and watched all the classes closely. Stock 4600 classes are dominated by Jeeps (JK and ZJ's) The ZJ is a popular choice because of the solid axle up front and V8 power. I've seen quite a few IFS 1st gen 4Runner's run the stock class and do decent. In fact, Dave Cole's son ran an IFS 4Runner for a couple years. 4500 and 4800 classes are crazy competitive. I'd suggest sticking to the stock class if you want to run a Toyota.

 

[Charles4x4]

The IFS the Ultra4 racecars are running vs the IFS you can get for any of your Toyota choices are completely night and day different. They are running trophy truck Currie front diffs and massive (f'ing MASSIVE) front CV's and A arms. Probably $30-40K in front end components alone. Your normal Toyota rack and pinon steering systems will fail in the rocks. Solid axles hold up way better than off the shelf IFS systems. You might be a little slower in the desert but at least you'll get a shot in the rocks with a solid axle.

I've been to KOH the last two out of the three races and watched all the classes closely. Stock 4600 classes are dominated by Jeeps (JK and ZJ's) The ZJ is a popular choice because of the solid axle up front and V8 power. I've seen quite a few IFS 1st gen 4Runner's run the stock class and do decent. In fact, Dave Cole's son ran an IFS 4Runner for a couple years. 4500 and 4800 classes are crazy competitive. I'd suggest sticking to the stock class if you want to run a Toyota.

Agreed, the cost and fabrication (custom chassis, narrowed front with center diff, Currie F9, RCV shafts, etc) required to get to 4400 level IFS is unattainable for a normal Toyota.

I also agree with your stance on KOH. But if you want to do EMC in a Toyota (which I clearly do), I think you only have a few options:
1) Do the Stock 4600 class in a V8 4Runner with IFS front with the best parts that are attainable (my list above, including a Tundra modified rack for strength and chromoly shafts) and see what happens.

2) Do the stock 4600 class in a SFA Toyota ('85 1st Gen 4Runner or 1st Gen Pickup/Hilux) with a 4 cylinder on leaf springs F/R.

3) Get stuck in the 4500 and 4800 class that are crazy competitive and spend 2x option 1 and 2 above just to get lost in the pack.

Based on these, Option 1 seems obvious right?

Also, from what I have seen, most EMC rigs fail on Lap 1 and never make it to the true Hammers trails. In fact, I think the course is intentionally designed to weed the pack before they can get clogged up in the rocks. I believe Option 1 could make it through Lap 1 and at least have a shot at the Hammers. Many 4500 and 4800 cars, even with their $75K budgets, fail simply because excessive modification leaves a long list of potential failure points - only 1 has to fail and you're out.

A less modified rig, while less "capable" on paper, is certainly more "reliable" in my opinion when pushed at a moderate pace.

 

[Volcom]

I also agree with your stance on KOH. But if you want to do EMC in a Toyota (which I clearly do), I think you only have a few options:
1) Do the Stock 4600 class in a V8 4Runner with IFS front with the best parts that are attainable (my list above, including a Tundra modified rack for strength and chromoly shafts) and see what happens.

2) Do the stock 4600 class in a SFA Toyota ('85 1st Gen 4Runner or 1st Gen Pickup/Hilux) with a 4 cylinder on leaf springs F/R.

3) Get stuck in the 4500 and 4800 class that are crazy competitive and spend 2x option 1 and 2 above just to get lost in the pack.

Based on these, Option 1 seems obvious right?

Either option 1 or 2. The rock sections will suck in option 1. The desert sections will suck in option 2. I think you'd have more luck getting further through the race in option 2. Lap 1 is a huge desert loop. Most guys (IFS and solid axle) can make that loop as long as you don't think your Robby Gordon out there in the open desert. It's a hard thing not to do. Trust me on this. Going fast in the desert is addicting and expensive. Even in my 84 4Runner on 40's, it was a blast ripping through the desert. But the big whoop sections had me down to 10-15 mph and on the bump stops on every hit.

Guess in the end is what do you feel like dumping a lot of $ into? If KOH was strictly your end goal, I'd say option 2. But since you want to wheel Moab and the Rubicon, option 1 is probably the better choice.

 

[Volcom]

Also, from what I have seen, most EMC rigs fail on Lap 1 and never make it to the true Hammers trails. In fact, I think the course is intentionally designed to weed the pack before they can get clogged up in the rocks. I believe Option 1 could make it through Lap 1 and at least have a shot at the Hammers. Many 4500 and 4800 cars, even with their $75K budgets, fail simply because excessive modification leaves a long list of potential failure points - only 1 has to fail and you're out.

A less modified rig, while less "capable" on paper, is certainly more "reliable" in my opinion when pushed at a moderate pace.

Most guys don't make the first lap because they push too hard. Once you get that helmet on and get into race mode, it's hard to slow down to save the car. Especially with guys blowing by you in the desert left and right. But keeping a safe pace will get you to the rocks unless something major happens like transmission, engine, suspension problems.

 

[Volcom]

Good thread on Pirate about stock 4600 solid axle Toyota truck
Toyota Racer #4611: KOH Stock Class Build - Pirate4x4.Com : 4x4 and Off-Road Forum