What's new

Best stock class 4600/4500 Base

TN-YJ

New member
Joined
Dec 31, 2020
Member Number
3249
Messages
2
My friends and I are wanting to build a 4500 or 4600 class KOH rig for 2022. One guy has a full machine/fab shop so we can build whatever we need but wondering what would be a great base to start with with. I'm personally leaning towards a XJ with 4.0 or 85' toyota 4runner or ex cab pickup. Both of these are relatively easy to find modified on the east coast so we have a decent base. any others we should be considering
 

Lil'John

Former #278
Joined
May 20, 2020
Member Number
488
Messages
902
Loc
Walking to the Rubicon
Wouldn't it be best to figure out which class before deciding on a vehicle?

4500 sounds like the "anything goes" as long as a stockish frame and body are retained while being on 37s. In which case, pick your favorite chassis and spend money.

4600 is the literally has to be stock with only some adjustments; stock motor and transmission, stock style suspension(linked only allowed if stock linked), axle and transfercase are open. 35" tires.
 

'84 Bronco II

El Chingón
Joined
May 19, 2020
Member Number
293
Messages
1,041
Loc
NM
Do you want to be competitive?

4500 is basically 4400-Lite with the main limitation being the 37" tires and mechanical steering connection, so get ready to blow metric shit tons of money if you aren't just racing for a finish. You need basically a full-blown tube buggy to be competitive, so it doesn't really matter what you start with other than the ability to run a solid axle front or IFS. Look up the Poison Spyder "Venom" build to see what I mean. I believe they claimed was a CJ2, but they essentially just bolted/welded the minimum required length of the frame rails to a full tube chassis, and the steering had push-pull cables for a "mechanical" connection.

The big advantage in my mind of doing 4500 over 4600 is that you can have a much more capable/uncompromised rig for recreational wheeling when you aren't racing or when you call it quits.

For 4600, there are several good choices, but it seems XJs, ZJs, WJs, and LJs have a consistently good track record. They all have a wheelbase that is a good compromise between highspeed stability and crawling on 35" tire, decent powertrains, and good suspension configurations.

the biggest attraction to 4600 is that being as heavily limited as it is, you can be a lot more competitive for less money. Don't mistake that for meaning cheap. You would be hard-pressed to put together a competitive rig for less than $20,000, and I believe many in the class have more like $40,000+ invested.
 
Last edited:
Joined
May 19, 2020
Member Number
248
Messages
998
Loc
socal
My friends and I are wanting to build a 4500 or 4600 class KOH rig for 2022. One guy has a full machine/fab shop so we can build whatever we need but wondering what would be a great base to start with with. I'm personally leaning towards a XJ with 4.0 or 85' toyota 4runner or ex cab pickup. Both of these are relatively easy to find modified on the east coast so we have a decent base. any others we should be considering

why 4500/4600?
 

tribal4krawler

DKA Motorsports
Joined
Jun 1, 2020
Member Number
1745
Messages
182
I think a JK is a very good 4600 car. Way more power than a xj/zj/mj/tj. The only problem is that they don’t look cool. Jon Schaefer is extremely fast and competitive with his old Savvy JK that’s essentially a copy of Jessi Combs old 4600. All that being said, I race a Comanche and we have over 40k invested in the truck now going into our second year of racing. I’d love to race 4500 but like others said it’s extremely expensive to be competitive. Even the legends/4800 class can be somewhat affordably gotten into, but to actually race a season and be in the hunt for a podium would cost a lot more than a 4600. Keep in mind, all this is not counting the entry fees, travel expenses, beer, food etc associated with racing an Ultra4 National series. I’d say over the last 3 years I’ve easily spent over 20-30k a year just in traveling/entry fees. It’s definitely not cheap but it’s a whole bunch of fun.
 

JR4X

wheeler
Joined
May 20, 2020
Member Number
445
Messages
1,336
Loc
Mancos Co
No matter what class you race in, building the car is the inexpensive part. Supporting a race habit is the difficult expensive part. I’ve raced both 4500 and 4900 cars. Keeping it prepped, travel time, fuel, consumables etc all end up being the harder part to come by as the year goes on.
 

Provience

Kill!
Joined
Jul 8, 2009
Member Number
15
Messages
8,063
Loc
Thurston County, WA
1) first you have to build it

2) it needs to stay together to finish on time

3) with 4600, if you finish on time, you're likely to podium :flipoff2:

as much as it sucks to break, i feel like it would suck even more to time out simply due to babying the thing too much :rasta: So starting with something that is completely broken and $200 with a good title might be reasonable, because then you already know you'll need to rebuild everything so that it can last a couple hundred miles.


fullsize would be neat.

1997-2012 expedition has a 119" wheelbase, V8 and IFS/IRS. it would be fine on a 35" tire despite needing a whole bunch of custom work. build the heck out of it, smooth transitions over the belly and hook it up with a serious quick winch and plan to winch early and often in the harder rock sections.

pre96 F-series single cab short bed is 117" if you want something you can use solid axles front and rear under


edit: in B4 "you can't run fullsize in johnson valley trails" haterz :flipoff2:
 

posford

:flipoff2:
Joined
May 19, 2020
Member Number
62
Messages
471
Loc
NH
pre96 F-series single cab short bed is 117" if you want something you can use solid axles front and rear under

Only F350s were SFA, rest were TTB, and F350 never came in a SCSB configuration.

Can you chop the frame on a F350 and stay 4600 legal? I ASSUME doing a SAS F150 isn't 4600 legal.

F150, with a D44/50 hybrid whoop scissors setup up front has the potential to hold up?

**Just looked at 4600 rules, no cut down F350s and no SAS'd F150s**
 
Last edited:

Provience

Kill!
Joined
Jul 8, 2009
Member Number
15
Messages
8,063
Loc
Thurston County, WA
Only F350s were SFA, rest were TTB, and F350 never came in a SCSB configuration.

Can you chop the frame on a F350 and stay 4600 legal? I ASSUME doing a SAS F150 isn't 4600 legal.

F150, with a D44/50 hybrid whoop scissors setup up front has the potential to hold up?

**Just looked at 4600 rules, no cut down F350s and no SAS'd F150s**

huh, interesting. I would think "super duty" and F250/F350 would allow for a SCSB SFA setup.

well, a durable upgraded F250 TTB setup would be dope, cut a bunch of weight out of it and romp.

or, expedition and IFS/IRS and haul ass :smokin:
 

posford

:flipoff2:
Joined
May 19, 2020
Member Number
62
Messages
471
Loc
NH
huh, interesting. I would think "super duty" and F250/F350 would allow for a SCSB SFA setup.

well, a durable upgraded F250 TTB setup would be dope, cut a bunch of weight out of it and romp.

or, expedition and IFS/IRS and haul ass :smokin:

If they consider all TTB to be equal, a 44/50 hybrid under a Ranger with a refreshed 4.0 and the right axle gears would make it light and stout.
 

JR4X

wheeler
Joined
May 20, 2020
Member Number
445
Messages
1,336
Loc
Mancos Co
If they consider all TTB to be equal, a 44/50 hybrid under a Ranger with a refreshed 4.0 and the right axle gears would make it light and stout.

The rules say axle and suspension upgrades are legal, You just have to keep it same/same as far as suspension type originally equipped. IE you can’t straight axle swap any IFS rig. Can’t IFS swap a solid axle. In your ranger example you can run any TTB you can conceive of as long as it’s still got coils and shocks, no coilovers. Longer RA, cut-n-turn any diff you want etc.

They let the straight axle cars swap out the factory axles for any other straight axle. You can do long arm or long travel suspension. I’ve been involved with the 4600 class reps and U4 in some rule change/clarification specifically to do with TTB. I wanted to build a D50 TTB Bronco but by the time I was done arguing with them and got the written clarification I wanted, I was over it and had a SXS built.
 

wvracer821

Red Skull Member
CAL4
Joined
May 27, 2020
Member Number
1546
Messages
205
Loc
Morgantown, WV
I always have this discussion with my friends over beers in the garage. I keep looking at 2011+ regular cab gas powered superdutys. I'm sure its 137" wheelbase would be miserable in the rocks though. the drivetrain is nearly bulletproof though.
 

Provience

Kill!
Joined
Jul 8, 2009
Member Number
15
Messages
8,063
Loc
Thurston County, WA
I always have this discussion with my friends over beers in the garage. I keep looking at 2011+ regular cab gas powered superdutys. I'm sure its 137" wheelbase would be miserable in the rocks though. the drivetrain is nearly bulletproof though.

isn't that about what the "stock" gladiator that ran had? it was something limo long similarly and it did very well.
 

JR4X

wheeler
Joined
May 20, 2020
Member Number
445
Messages
1,336
Loc
Mancos Co
photo42053.jpg
Not sure a superduty would even make the long list of vehicles I’d consider for a race rig, let alone the short list. But this thing is kinda cool.
 

Provience

Kill!
Joined
Jul 8, 2009
Member Number
15
Messages
8,063
Loc
Thurston County, WA
Not sure a superduty would even make the long list of vehicles I’d consider for a race rig, let alone the short list. But this thing is kinda cool.

how much weight could you cut out of one would be the thing to figure out. completely stripped and race prepped, probably a good bit of weight savings, long travel leaf spring rear and radius arm coil sprung front wouldn't be a bad setup

edit: width being what it is, a small cab cage and no rocker protection and such and let the body eat. as long as it shows up with mostly straight panels, everything else can be tinfoil "self clearancing" on the trail.
 

Provience

Kill!
Joined
Jul 8, 2009
Member Number
15
Messages
8,063
Loc
Thurston County, WA
for 4600 class I'm sure they get pretty strict with how much you could cut out.

gotta keep all the sheet metal, but tube doors, nothing that isn't sheet metal

The exception to this rule is the allowance for rocker panel protection limited to the area between the wheel wells. You may cut into the body and/or reinforce this area. You may not interfere with the mating surface of 2020 Ultra4 Rulebook V5.0 35 the stock door and doorsill. The stock doorsill must be retained and unaltered.

so cut a straight line from front wheelwell to rear wheelwell at the door sill, cut it up and apply some ~0.90 AL as a "rock guard"

fiberglass front fenders

it would be a bruiser with 35" tire so the question of "lower it or not" for belly height would be an interesting one, but i think a good and fast winch would be a priority with the expectation of pulling cable to get the belly unhung would be a must


edit: swapping the Tcase for an atlas would probably save a bit of weight if they are still using steal housings, can't really touch the transmission, but new heads if they don't use AL already.
 
Last edited:

Yotota

Truck nerd
Joined
Jun 6, 2020
Member Number
1870
Messages
439
Loc
SW WA
gotta keep all the sheet metal, but tube doors, nothing that isn't sheet metal



so cut a straight line from front wheelwell to rear wheelwell at the door sill, cut it up and apply some ~0.90 AL as a "rock guard"

fiberglass front fenders

it would be a bruiser with 35" tire so the question of "lower it or not" for belly height would be an interesting one, but i think a good and fast winch would be a priority with the expectation of pulling cable to get the belly unhung would be a must


edit: swapping the Tcase for an atlas would probably save a bit of weight if they are still using steal housings, can't really touch the transmission, but new heads if they don't use AL already.

This would be a fun build to see in action.

It would probably not be a difficult build either. Find a barebones XL spec 4WD regular cab/longbed F250 with the 6.2L gasser and 6sp auto. Keep the engine and trans stock, add a bigass trans cooler. Definitely an Atlas 4 case and heavy wall drivelines. Gears, rear spool, front ARB. Maybe axle shafts if you're spending the money, might not need them on DOT 35s though. Deaver rear springs sprung under, good front coils, stock-ish height suspension, 2.5" shocks of your choice. 1" solid mount body lift, 1" drivetrain lift, flat belly, AR plate skids into AR plate boatsides up to the door sill. Some low profile bumpers, damn good big winch, interior cage, fully gutted interior and no glass, half doors. Otherwise gut and strip everything possible. Maybe some glass fenders if there is weight to be saved.

On good 35s this would be really fun to smash around, and should in theory finish the race with a smart driver (and athletic co-driver to pull winch cable).
 
Last edited:

Provience

Kill!
Joined
Jul 8, 2009
Member Number
15
Messages
8,063
Loc
Thurston County, WA
This would be a fun build to see in action.

It would probably not be a difficult build either. Find a barebones XL spec 4WD regular cab/longbed F250 with the 6.2L gasser and 6sp auto. Keep the engine and trans stock, add a bigass trans cooler. Definitely an Atlas 4 case and heavy wall drivelines. Gears, rear spool, front ARB. Maybe axle shafts if you're spending the money, might not need them on DOT 35s though. Deaver rear springs sprung under, good front coils, stock-ish height suspension, 2.5" shocks of your choice. 1" solid mount body lift, 1" drivetrain lift, flat belly, AR plate skids into AR plate boatsides up to the door sill. Some low profile bumpers, damn good big winch, interior cage, fully gutted interior and no glass, half doors. Otherwise gut and strip everything possible. Maybe some glass fenders if there is weight to be saved.

On good 35s this would be really fun to smash around, and should in theory finish the race with a smart driver (and athletic co-driver to pull winch cable).

yeah, now finding the team willing to drop ~35k or so on the rig to get it running, built and down there might be a different story :laughing:

I guess having "race stock" fenders and "trail" fenders would be a reasonable way to get more use out of it, then you could run a more reasonable 40-42" tire for the rest of the year
 

Yotota

Truck nerd
Joined
Jun 6, 2020
Member Number
1870
Messages
439
Loc
SW WA
yeah, now finding the team willing to drop ~35k or so on the rig to get it running, built and down there might be a different story :laughing:

I guess having "race stock" fenders and "trail" fenders would be a reasonable way to get more use out of it, then you could run a more reasonable 40-42" tire for the rest of the year

Definitely. Build the rig for 39s or 40s, then downsize for the race with a separate set of fenders to meet the "within 2" of tire" rule.

Budget option: find a salvage title truck from Copart or a tow auction. Building a rig to finish the race won't be cheap no matter how you approach it... It will either be $$$+lots of time and labor, or $$$$$+less time and labor.
 

Provience

Kill!
Joined
Jul 8, 2009
Member Number
15
Messages
8,063
Loc
Thurston County, WA
Definitely. Build the rig for 39s or 40s, then downsize for the race with a separate set of fenders to meet the "within 2" of tire" rule.

Budget option: find a salvage title truck from Copart or a tow auction. Building a rig to finish the race won't be cheap no matter how you approach it... It will either be $$$+lots of time and labor, or $$$$$+less time and labor.

figure the entry fee, trip and safety equipment to pass test is ~$20k :laughing:
 

pennsylvaniaboy

Well-known member
Joined
Jun 27, 2020
Member Number
2192
Messages
224
This would be a fun build to see in action.

It would probably not be a difficult build either. Find a barebones XL spec 4WD regular cab/longbed F250 with the 6.2L gasser and 6sp auto. Keep the engine and trans stock, add a bigass trans cooler. Definitely an Atlas 4 case and heavy wall drivelines. Gears, rear spool, front ARB. Maybe axle shafts if you're spending the money, might not need them on DOT 35s though. Deaver rear springs sprung under, good front coils, stock-ish height suspension, 2.5" shocks of your choice. 1" solid mount body lift, 1" drivetrain lift, flat belly, AR plate skids into AR plate boatsides up to the door sill. Some low profile bumpers, damn good big winch, interior cage, fully gutted interior and no glass, half doors. Otherwise gut and strip everything possible. Maybe some glass fenders if there is weight to be saved.

On good 35s this would be really fun to smash around, and should in theory finish the race with a smart driver (and athletic co-driver to pull winch cable).

I think this is a great concept, but you guys are missing the glory here. If you cant modify the rockers, plate the belly, do the bumpers/fender deal, and let the rockers and bedsides self clearance.....and shave the axles as much as you can...
 

Provience

Kill!
Joined
Jul 8, 2009
Member Number
15
Messages
8,063
Loc
Thurston County, WA
I think this is a great concept, but you guys are missing the glory here. If you cant modify the rockers, plate the belly, do the bumpers/fender deal, and let the rockers and bedsides self clearance.....and shave the axles as much as you can...

you can modify the rockers between the wheel wells up to the door sills.

hence the "replace with 0.040" AL sliders" and call it a day comment :laughing:
 

Yotota

Truck nerd
Joined
Jun 6, 2020
Member Number
1870
Messages
439
Loc
SW WA
I think this is a great concept, but you guys are missing the glory here. If you cant modify the rockers, plate the belly, do the bumpers/fender deal, and let the rockers and bedsides self clearance.....and shave the axles as much as you can...

As Provience mentioned, that's all allowed. I had the rulebook open and confirmed that everything I called out was allowed in 4600.

I haven't crawled under a 2011+ Super Duty, so it may not even need the drivetrain/body raised to stay above the framerails. Either way I would still go with AR plate covering some framed flat belly skids and boatsides as the truck will be grinding over half the rocks on the trail. I'm sure everyone will hear it coming a mile away...
 

JohnnyJ

Low Range Drifter
Joined
May 19, 2020
Member Number
169
Messages
124
Loc
SE Michigan
I wonder how long it will take before every 4600 wannabe contender takes the lead from Jesse and moves to portals, at least for KOH. Sure, they're spendy; but I can't think of a better way to work around the lack of body mods and limited tire size. I wonder how possible it would be to use a stock hummer knuckle on a modified factory IFS?

For 4500, I would not use any frame or body part from a stock vehicle. Tube chassis with just enough "body work" to make it class legal.
 
Top