• Forum membership has its advantages....

Trick/trophy truck 4wd ?

bajadreamer

Well-Known Member
A 4WD TT with a 1,000-1,200 HP and 1,500-2,000 lbs-ft TQ Duramax engine would be a mean combination! Anyone have a few hundred thousand to loan me for the build???
I think I overheard someone building one of those exact trucks .. time will tell


I'm nobody from nowhere
 

BajaFand

Well-Known Member
Actually I think that there is a difference over 4 foot holes. 4WD trucks do not have as much wheel travel in the front as 2WD trucks, the axles are the limiting factor (at least for now). I think that it will always be a trade off between which works better overall, but I expect to see more 4WD trucks in the near future.
Back in the day with the Herbst and Big Mac 4wd trucks this was definitely the case. If the new Geisers have as much front travel as they are claiming then there's not much difference I wouldn't think.


Sent from the RDC Mobile App. Get it for your IOS device today
 

dan200

#BSF200
I am still apprehensive at believing that someone would be able to 200 miles on a set of tires. 500 to me is crazy. I mean, they could do 200 or 500 I guess but, should they? Running any existing tire compound or brand for too long is just risky. (Am I alone here?)

Our best TT pit time for rears and full fuel was 35 seconds. I watched Geiser do one in 36 seconds this past weekend. Before we went to a pressure pro we were doing them in about 45 seconds. Ive stop watched Andy Mac, Rob Mac, TSCO, and a few others and I am proud to say we can hang there with their pit stop times.

Obviously seconds matter but, I think it could be argued that you could do 4 tires in the same time (or very close to it) as just rears. (you would need a cool jack system so the whole truck is off the ground at the same time, and safely, and you would need basically twice as many guys to do all those tire changes at once, BUT the F1 guys can do this already, so?
 

Jorge Rodriguez

50% tortoise 50% hare
Apdaly Lopez just posted a video of the start of the Mint 400 on FB where he and Justin Matney start side by side and in the few minutes of infield and loose sharp turns, Matney doesn't pull away more than 1-2 car lengths and by the end of the video, Adpdaly has reeled him in.

It was a short video so I'm not sure if Matney pulled away after this, but I figured that the start would be the biggest advantage for the 4x4.
 

PeterT

Well-Known Member
Tire wear has been mentioned as a factor, but I am also curious about fuel economy. If you are getting the power to the ground better, does fuel economy improve? And if it does, that along with reduced tire wear is a definite advantage, in that you can go longer between pit stops, and have fewer pit stops per race.
 

J Burleson

Well-Known Member
A 4WD TT with a 1,000-1,200 HP and 1,500-2,000 lbs-ft TQ Duramax engine would be a mean combination! Anyone have a few hundred thousand to loan me for the build???
Why? Are you thinking of just building half of a truck or do you already have a couple hundred thousand saved?! Lol
 

vegasloki

Well-Known Member
Obviously seconds matter but, I think it could be argued that you could do 4 tires in the same time (or very close to it) as just rears. (you would need a cool jack system so the whole truck is off the ground at the same time, and safely, and you would need basically twice as many guys to do all those tire changes at once, BUT the F1 guys can do this already, so?
F1 crews are dealing with much lighter cars (about 1550 lbs with the jockey driver) and hand jack the car. They also don't fuel, one reason they get sub 3 sec stops. The other reason is between 16-18 work on the stop. There are 12 just for tires. Tire on, gun, tire off for each corner.

I don't know about lifting a 5k lb TT all 4 wheels off the ground in the dirt with an auto jack or even ground jacks. I suppose some sort of massive air jack system either one that can slide under on each side, or front and rear. It would be pretty big and require a pretty stout air supply so it may not make sense to use an auto jack method. You could use shop air from an external compressor (Indycar uses this for their auto jack) but then you couldn't use it out on the course.

You guys are mostly a sharp bunch. I'd bet any reliability issues with AWD will be addressed and then the logistics or tires and whatever advantage AWD may have will come into play. If it's a better way someone will figure it out.
 

ACME

Well-Known Member
Because the tires aren't spinning all the time like a RWD truck, they are pulling. Which also means TTs don't need to change the rear tires every 200 miles, which potentially makes them faster in the pits too.

Could it be argued that since they slip less, they are digging less of a hole than a two wheel drive? I think it could.

I think they are more efficient going through a corner. Much more. Big HPwith less traction would be less efficient
Sent from the RDC Mobile App. Get it for your IOS device today
I agree they get more traction and your theory makes sense but in reality you are off. The reality of 4wd IMO is: If they all (2wd/4wd) go 120MPH on a lakebed or 60 or 80mph in the same whoop section then the difference-benefit is in cornering speeds and places with less traction/sand/silt etc... where a 4wd will have more traction and forward drive.

You think the top drivers that are vying for the win are going to go the same speed in a corner, across the whoops or in less traction conditions because they have the 4wd traction, thus causing less damage to the course? They will just hammer through that section that much faster to try and get even more traction and go just as hard as a 2 WD with all the tires churning.

The 4wd in fact will help them turn in the corner and they will go even faster and push that same traction envelope but now with all 4 tires spinning. Yes, the 2WD will throw a roost off the back but the 4wd throw a roost off the all 4. Maybe not as dramatic as just 2 but the same amount or more of material will be displaced.

Go watch a top Ultra 4 in the lead pack at Hammers in 4wd and tell me they throw less charging hard than they would if they were only 2wd. Then compare a Pro 2 & 4 and you'll notice it's about the same and probably more on the Pro 4.
 

Cuban Mike

Member
So what's the verdict on course wear and tear? 2wd or 4wd? Seems obvious but a few of u guys are saying 4 tires throwing dirt around is actually better for course deterioration. Again, KOH and desert racing are 2 different animals. KOH cars have raced BITD, will Geiser put 42" beadlocks and gear down their TT to race KOH? Nausea setting in just think about it
 

dan200

#BSF200
Yes, the 2WD will throw a roost off the back but the 4wd throw a roost off the all 4. Maybe not as dramatic as just 2 but the same amount or more of material will be displaced.
Like you, I have no science besides what I saw happen and I 100% respectfully disagree with you on this.

I think less dirt will be displaced because more power is transfered to the ground more efficiently. spinning/roosting proves to less efficient. Overall a 4wd will be more surgical and spin tires less than a 2wd.
 

Dirty Harry

Well-Known Member
Go watch a top Ultra 4 in the lead pack at Hammers in 4wd and tell me they throw less charging hard than they would if they were only 2wd. Then compare a Pro 2 & 4 and you'll notice it's about the same and probably more on the Pro 4.
Actually I just got done racing King of the Hammers, thanks. And I have raced with Chad Hall in his Samco Fabrication 4WD 6100 truck. They don't spin the tires nearly as much as a 2WD TT, they just grab and go forward rather that moving a bunch of dirt with spinning rear tires. I don't expect that to be a factor that would motivate someone to build a 4WD truck, but it has been my firsthand experience that they are easier on tires and drivetrains and the course itself.
 

ltr450rider

Well-Known Member
So far, 4WD has not been easy on drivetrain components, at least for the front diffs, which seems to be the weak link. Once they get that figured out and strong enough, will that weak link move somewhere else in the drivetrain?

Transmissions are still a little more finicky and now throw in a transfer case that needs to withstand the abuse from the front and rear shock loads. The rear end seems to be pretty well figured out at this point, so the questionable parts come down to transfer cases and front diffs.

Time will tell if having all 4 tires spinning is easier on drivetrains or not. There is not enough time and data out there to make that decision. Once you get trucks finishing races and running competitively, then we will see where we're at. In my opinion, it will not be any easier since you now have 4 points of contact that grab and shock load the entire drivetrain rather than just 2 from the rear.

I do believe it will be easier on tires and cause less damage to the course since there is less wheel spin from the rear tires trying to push the truck forward and digging holes.
 

JaysinDesignz

Well-Known Member
Its being figured out by Rock Donkeys as Ultra4 gets bigger and bigger. Dollars are in the technology now and its all thanks to Rock Donkeys.

I come from rock racing and 100% desert racing now.
I run little turbo 4cyl putting out 350HP. 4wd is unmatched in the long arroyos and silt. Even stock V8 motors Im easily catching in long deep sand arroyos.
 

ACME

Well-Known Member
Actually I just got done racing King of the Hammers, thanks. And I have raced with Chad Hall in his Samco Fabrication 4WD 6100 truck. They don't spin the tires nearly as much as a 2WD TT, they just grab and go forward rather that moving a bunch of dirt with spinning rear tires. I don't expect that to be a factor that would motivate someone to build a 4WD truck, but it has been my firsthand experience that they are easier on tires and drivetrains and the course itself.

Interesting comment on the Ultra 4's as in the wide open sections the top guys threw a ton up while gaining traction with all 4 tires in the areas we watched them in, but I defer as I have only watched them.

As for comparing a 6100 truck to a TT again apples and oranges. A better comparison is a Pro2 vs 4 where I believe the only difference is 4wd and not 300Hp. In this video it shows a pretty good head to head and at the least they seem equal?

justin matney trophy truck - Bing video
 

ltr450rider

Well-Known Member
I find it a little bit harder to compare KOH vehicles to trophy trucks. Yes, the KOH trucks are going pretty damn fast in the open, but not quite as fast as a TT. When a KOH truck is on the rocks and bouncing around, that is the most amount of stress on their drivetrain, but I feel that the shock loads going through a TT at speed across the whoops is more stressful than that of a KOH on bouncing on the rocks.

With that said, why hasn't someone put the KOH drivetrain in a TT?

The way I see it, the KOH trucks are already competing in the open desert as they just did this past weekend at the Mint, but they weren't anywhere near the speed of the TT. The only one I saw going fast enough was Casey Currie (His motor sounded effin rad by the way). I don't know what cause him to DNF.
 

Bricoop

Well-Known Member
F1 crews are dealing with much lighter cars (about 1550 lbs with the jockey driver) and hand jack the car. They also don't fuel, one reason they get sub 3 sec stops. The other reason is between 16-18 work on the stop. There are 12 just for tires. Tire on, gun, tire off for each corner.

I don't know about lifting a 5k lb TT all 4 wheels off the ground in the dirt with an auto jack or even ground jacks. I suppose some sort of massive air jack system either one that can slide under on each side, or front and rear. It would be pretty big and require a pretty stout air supply so it may not make sense to use an auto jack method. You could use shop air from an external compressor (Indycar uses this for their auto jack) but then you couldn't use it out on the course.

You guys are mostly a sharp bunch. I'd bet any reliability issues with AWD will be addressed and then the logistics or tires and whatever advantage AWD may have will come into play. If it's a better way someone will figure it out.
On average, how high do you need to lift a TT (front and rear) to change a tire?
 

Bricoop

Well-Known Member
Interesting comment on the Ultra 4's as in the wide open sections the top guys threw a ton up while gaining traction with all 4 tires in the areas we watched them in, but I defer as I have only watched them.

As for comparing a 6100 truck to a TT again apples and oranges. A better comparison is a Pro2 vs 4 where I believe the only difference is 4wd and not 300Hp. In this video it shows a pretty good head to head and at the least they seem equal?

justin matney trophy truck - Bing video
Wouldn't it all just depend on the HP? If you put a 2Kftlb engine in a 4wd all 4 would spin like crazy.

A 4wd with a TT motor will throw less dirt per tire than a 2wd TT. But I guess that begs the question, does a 4wd throw less than half the dirt per tire than a 2wd does per tire?
 
Top