Future of KOH 4400 chassis/car development?

[SLOWPOKE693]

Any idea what ultimately made him stop running?

Lack of sway bar and rear section of the chassis would be my guess. I bet it handled like shit after they pulled it off in the pits.

 

[YotaAtieToo]

Last year or the year before I thought it was an upper a arm issue that broke while he was in the lead?

I don't know what made him call it, maybe worried about rolling it with no sway bar?

 

[ridered3]

And wasn't that the second time the whole back end broke off that car? Didn't it happen last year also?

I believe that is the same one that the backend fell off of but not 100%. It’s hard to keep all the different Gomez apart at times.

 

[ridered3]

Last year or the year before I thought it was an upper a arm issue that broke while he was in the lead?

I don't know what made him call it, maybe worried about rolling it with no sway bar?

That was a different Gomez brother but don’t recall exactly which one yet.

 

[06h3]

Lack of sway bar and rear section of the chassis would be my guess. I bet it handled like shit after they pulled it off in the pits.

I thought the Gomez car with the back end of the car off also had a bungee cord holding the t case lever back because it was popping out of gear. I know the announcers said that yesterday about 1 of the Gomez cars. I thought it was Marcos but it’s tough to keep track

 

[SLOWPOKE693]

I thought the Gomez car with the back end of the car off also had a bungee cord holding the t case lever back because it was popping out of gear. I know the announcers said that yesterday about 1 of the Gomez cars. I thought it was Marcos but it’s tough to keep track

You are right, I forgot about the t-case issue.

 

[JR4X]

We are playing here with sprung and unsprung weight. The cars have to get heavier to resist the extra motion weight of 42" tires with liners (150#+) and now portals (50lbs+). I believe UFO (Joe Thompson) has resisted the portals because the front is relatively lite, and only sees weight on braking. I know I was warned about tilting front shocks inward or rearward. It had more to do with force location than progressive/regressive geometry.

When lay down shocks were introduced to offroad Moto in the early 70.s, there was a lot of trial and error with air shocks. The riders also had to get used to the transition from 5" to 8" to 12" of rear travel. Once the valving and pressures were worked out, springs were re-introduced to solve the heat/pressure issue. In the case of race cars visibility over the hood is a major issue and where lay down compromises can be made.

But what if the max desired tire size is a 37/38? What could be feasibly down sized then?

A rear engine car can help controlling the REAL heavy rear axles. There is room for straight up shocks. Newer TT's with 36" articulation are sporting shocks close to 8feet.

Again. Live valve is changing a LOT of this thinking.

I think mid engine is the move but not with a LS. Hope to get to have live valve some day.

 

[YotaAtieToo]

That was a different Gomez brother but don’t recall exactly which one yet.

I used to work for them, met JP quite a few times but only met Marcos and Raul once. Even still I sometimes mix up Marcos and Raul.

I really thought it was Marcos and Raul ended up getting the win.

 

[ridered3]

I used to work for them, met JP quite a few times but only met Marcos and Raul once. Even still I sometimes mix up Marcos and Raul.

I really thought it was Marcos and Raul ended up getting the win.

Ha that makes me feel better. I’ve only met them in person twice, but hung out with Marcos at the Dirty Turtle Kentucky race years ago. I always root for him simply due to that day.

They should keep the same graphics and facial hair year to year so it’s easier on all of us.

 

[JR4X]

I used to work for them, met JP quite a few times but only met Marcos and Raul once. Even still I sometimes mix up Marcos and Raul.

I really thought it was Marcos and Raul ended up getting the win.

I’ve been around them a fair bit and am never confident in my identification of each one. Marcos is the easy one for me, it’s JP and Juan I can’t tell apart, I think 🤔

 

[ridered3]

I’ve been around them a fair bit and am never confident in my identification of each one. Marcos is the easy one for me, it’s JP and Juan I can’t tell apart, I think 🤔

Kinda like when talking to identical twins. Never name them until they drop the other siblings name in conversation.

 

[YotaAtieToo]

I’ve been around them a fair bit and am never confident in my identification of each one. Marcos is the easy one for me, it’s JP and Juan I can’t tell apart, I think 🤔

JP actually stands for Jaun Pablo


JP is smaller

Marcos has the scar on his face and the other is Raul

There is also a 4th brother, but I guess that's not supposed to be brought up

 

[Bebop]

After today, I feel like one of the changes to 4400’s will be better winches…although realistically no one will change anything and/or test their winch before they need it during the race.

Cade Rodds winch line being fucked like 2ft out was total amature hour shit. Part of race prep should be unspooling the line and respooling it loosely so it's not pinched and won't come out. And the freespool not working is unacceptable....

Or Raul not being able to upright himself...

But talking about winching is bad in the states...

 

[ridered3]

Or Raul not being able to upright himself...

But talking about winching is bad in the states...

Can’t talk about winching methods or those made up measurements all the other countries use either

 

[Bebop]

Hard to see solid rear going away. Easier to get big travel numbers and does way better on uphill rock sections. Also damn near bullet proof and simple compared to irs.

Except for driveshafts, I was surprised how many had driveshaft issues this year. If you can make a lower link hold up, how can you not make a driveshaft hold up?

This driveshaft you compare to a lower link needs to spin at 4171rpm vibration free (calculation made using a top speed of 100mph, with 40" tires and a 4.88 gear ratio). Not an easy feat. At all.

 

[Bebop]

I think mid engine is the move but not with a LS. Hope to get to have live valve some day.

LS will never be the move.
Ever look at some of the legit race engines from series like WRC, DTM etc?

They got some 1.6 liters making 500+lbs/ft of torque at 2500rpm with crazy flat torque curves. They also need an engineer just to start them and a team of development guys to manage. But the potential exists.

Sadev and other companies have transmissions that are the size of a big shoe box that will hold etc etc.

But now you're not talking about a grass roots sport. You'd need a legit motorsport effort, things that even Healy couldn't provide.

 

[ridered3]

This driveshaft you compare to a lower link needs to spin at 4171rpm vibration free (calculation made using a top speed of 100mph, with 40" tires and a 4.88 gear ratio). Not an easy feat. At all.

Shaft carnage for example

 

[aczlan]

JP actually stands for Jaun Pablo
JP is smaller
Marcos has the scar on his face and the other is Raul

There is also a 4th brother, but I guess that's not supposed to be brought up

Aaron Z

 

['84 Bronco II]

I find these discussions interesting so I'll write down some of my thoughts.

I mentioned it previously, but after the podium scare this year, I think a lot of teams should be taking notes from the UTVs. There are already 4400 cars that are basically scaled up UTVs (Loren's car last year, Lasernut/Cameron Steele's car, etc.), but I think what the CanAm success really drives home is that cars need to get smaller and lighter. The fact that the Can Ams are competitive for the win with less than half the horsepower and 35/37" tires should be embarrassing to the top 4400 guys.

The lighter weight means that the cars are easier on parts as well as easier to recover, and being smaller gives them more line options to sneak through traffic jams and get through difficult sections as highlighted by the Scherer/Cade Rodd debacle in Outer Limits.

Perhaps start looking to WE Rock style drivetrains with small displacement, all-aluminum, turbo charged engines. You could easily save a couple hundred pounds compared to a small block V8, and use lighter transmissions and transfer cases behind them as well as reduce the size of the chassis which would have significant compounding weight reduction. With less weight, you don't need as much horsepower to maintain the same power to weight and you would reduce the stresses on everything. It's all about being as efficient with material use as possible and matching your components well.

I think solid axles are still competitive, but I think people need to do more to build to their advantages:

• Obviously, you can get much more steering angle out of a solid axle since the suspension travel doesn't affect the steering joints. I think building a race chassis that can utilize 45-50° of steering with 40-42" tires would be a huge benefit to being able to weave through the rocks compared to an IFS car that might have 30° if that much. I honestly do not know how much angle the Miller Motorsport/Big B guys or Slawson are running, but I know 45-50° is difficult to package without designing around that much steering angle.
• You can achieve more jounce travel and maintain a much narrower track width with a solid axle compared to an independent setup since you don't have to fight CV angles. It seems like a lot of the IFS guys are well over 90" outside to outside of the tires which greatly limits their line option and oportunites for passing in the rocks. Being narrower also helps impove your axle "breakover" angle for a given tire size and helps immensely through boulder fields like all of the Hammers trails.
• You can have more suspension travel than an independent design. I think I remember reading that most of the 4400 IFS setups are in the 20-24" of travel range whereas with a solid axle, you are only limited by your driveshaft angles and how much compression travel you can get before the belly hits the ground. Additionally, the solid axle doesn't lose ground clearance during compression like an independent setup which seems like a big deal for blasting through boulder fields.
• The solid axle helps for chassis stability on steep climbs with offset hits like what took Raul Gomez out this year. Watching the replay, I doubt Slawson or Miller would have backflipped on that same line since the tire dropping down on the driver side would have helped pull the passenger side up and kept the car settled. Solid axles will also put down more traction in articulated scenarios since the compressed side forces the opposite side down and maintains pressure whereas independent suspentions have the tendancy to lft the opposite side.

Pretty much all of the top teams with IFS are running portals these days, so it seems like more teams could apply it to solid axles and get them up above the belly of the car for easy boulder field bashing. I am also not sure how many solid axle teams are playing with the latest and greatest shock tech like we are hearing about on the independent cars.

A lot of the driving force behind the car design and development comes down to how Dave designs the courses. I don't think KOH is typically won in the desert, but it is certainly lost in the rocks. I think cars need to focus more on being nimble in the rocks than outright speed in the desert. I really like how Dave has been throwing rocks early into the "Desert" lap the last couple of years. He needs to have them turn up S.O.S. after Turkey Claw next year I also really liked the year he had Deadblow as the last trail before the finish. I think having a big "fuck you" rock trail at the very end is the way to go and push the attrition higher. Have them go UP Bloody Mary or Dead Blow at the end of lap 3 next year

 

[Bebop]

I think solid axles are still competitive, but I think people need to do more to build to their advantages

I don't think there is any way to improve on the Miller's design without compromising something else.

 

['84 Bronco II]

I also forgot to mention, I am surprised teams haven't done much R&D with modern 8, 9, and 10 speed transmissions. I know some folks like Scherer are already running single speed transfer cases like SCS, but with modern 8-10 speed transmissions, there would be basically no downside to going with a single speed since you would have plenty of gear range in the transmission. The ZF 8HP 80 for instance has an 8.59:1 gear spread (5.50 1st and .64 8th) compared to only 2.48:1 for a TH400. That means a ZF 8HP 80 wold have a lower crawl ratio with a 1:1 transfercase than a TH400 with a 2:1 transfercase while still having two overdrives allowing for even deeper axle gears or higher top speed without ever having to stop and shift a transfercase between high and low. In fact, a ZF 8HP 80 would have the same total gear spread with a 1:1 transfer case as a TH400 with a transfercase with a 3.46 low range and have tighter gear splits to boot. I notice a lot of teams slowing down to shift this year which adds up over the two rock laps going between trails.

 

['84 Bronco II]

I don't think there is any way to improve on the Miller's design without compromising something else.

How much steering angle does Erik have, how much vertical travel does he have, and how wide is he outside to outside tire? I honestly don't know, so I would be curious to see how it compares to IFS builds. The article someone linked about Raul's car says he has 21" of front travel and a 92" track width.

His chassis would probably have to be completely redisigned to make effective use of portals, but I think they would help provided they are part of the design from the initial concept.

 

[Bebop]

How much steering angle does Erik have, how much vertical travel does he have, and how wide is he outside to outside tire? I honestly don't know, so I would be curious to see how it compares to IFS builds. The article someone linked about Raul's car says he has 21" of front travel and a 92" track width.

50 degrees
18"
and I'm not sure on width. But I've seen it upclose and its narrower than my car (which is 91" wide).

His chassis would probably have to be completely redisigned to make effective use of portals, but I think they would help provided they are part of the design from the initial concept.

Solid axle portal cars are retarded.
Why not add another 100lbs+ of unsprung weight per axle on something that's already at a huge disavantage for that very reason?

 

[SLOWPOKE693]

The only thing left to throw at a top of the line solid axle 4400 car would be smart shocks and even then it's not going to be the game changer that closes the gap between SA and IFS. I'm 100% a solid axle guy but also see the writing on the wall. IFS/IRS is here to stay and is only going to get better with time and that's going to put an even bigger gap between it and SA 4400 cars.

 

[SLOWPOKE693]

I don't think there is any way to improve on the Miller's design without compromising something else.

That car could be ALOT smaller. Yes it will be more difficult to work on but holy hell those cars are huge compared to other U4 chassis.

 

[JR4X]

50 degrees
18"
and I'm not sure on width. But I've seen it upclose and it’s narrower than my car (which is 91" wide).

One extra note there. Miller and Blylers have east coast and west coast axle assemblies. They have retard width axles for Hammers & short course races and then narrower ones they swap in for running in the trees on their home turf. Pretty cool that they can just slam the narrower ones in, not lose any degrees of steering and zip through the trees while the IFS cars are stuck with what they’ve got.

Cody Addingtons dragon is 100” to the outside of the tires. I have no reason to believe Cades car isn’t exactly the same width.

 

[Rangerrod]

This isn’t really chassis related but is. Starlink can it be useful enough and accurate enough that someone could remotely co-dawg the race? Like them watching in real time they’re in drivers ear giving directions?

I could see technology removing the co-dawg and then the push going back to lighter single seaters real quick. Only disadvantage is winching and spotter.

 

[Bebop]

That car could be ALOT smaller. Yes it will be more difficult to work on but holy hell those cars are huge compared to other U4 chassis.

IDK man, I feel like my car is bigger and a UFO was DEFINITELY bigger.

 

[Bebop]

One extra note there. Miller and Blylers have east coast and west coast axle assemblies. They have retard width axles for Hammers & short course races and then narrower ones they swap in for running in the trees on their home turf. Pretty cool that they can just slam the narrower ones in, not lose any degrees of steering and zip through the trees while the IFS cars are stuck with what they’ve got.

Cody Addingtons dragon is 100” to the outside of the tires. I have no reason to believe Cades car isn’t exactly the same width.

I remember that Jake Hallenbeck's B2 Bomber was sold with both axle assemblies.

I didn't know that Miller had both width too, but that makes sense.
I saw it upclose at AOP (TN) so one would assume it had the narrow ones on.

 

[SLOWPOKE693]

This isn’t really chassis related but is. Starlink can it be useful enough and accurate enough that someone could remotely co-dawg the race? Like them watching in real time they’re in drivers ear giving directions?

I could see technology removing the co-dawg and then the push going back to lighter single seaters real quick. Only disadvantage is winching and spotter.

Fleet of drones following and leading the car throughout the course would work for navigation and spotting through a team member monitoring drone video.

Don't get stuck and you don't have to winch solves the last problem.