Future of KOH 4400 chassis/car development?

isn't Loren running an SCS? or does he have some kind of one way front diff like a pro4?
 
snivilous said:
And just to throw this up there since the ****ting on WEW Watt's link, coincidentally he just made a youtube video detailing the path he went down and why:

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In that video, his set-up looks like it is working fairly well and it looks well designed.

Much better designed than what was posted earlier:

2big bronco said:
All the travel
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Ghetto Fab. said:
Any idea what a good amount of clearance is? Obviously more is better, but that compromises other design goals.
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Desert I like minimum 5" on an IRS car. By the time you compress the tires, that doesn't leave much for road crown. IFS can get a little closer due to impact angles. Solid axle rear fuel cell, 4".
 
'84 Bronco II said:
Over driving the front axle is getting more popular in the rock crawling scene to improve steering, take some bind out when forcing the front into big walls/boulders, and to "stretch" the chassis out to keep it planted and stable on big climbs. I can't think of a situation where it would be beneficial to overdrive the rear. It seems to me that the heavier the vehicle is and the more speed that's involved, the less overdrive you can get away with. With RC crawlers, it is pretty common to run 20-40% front overdrive, I think some of the WE Rock guys are around 8-9%, and I have heard trail guys talking about 4-6%. I can't imagine with the speeds and weights of the rigs in 4400 that they would want more than a percent or two.
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Being able to vary the front overdrive based on terrain would be really interesting. I think there's systems that do that in road race or rally cars, but IDK.

This is something that might actually be easier to do if your front drive was electric.

I say interesting because who know if it'll be worth the effort/complexity until you try it. Horschel's 4ws car seems like it would be worth it, but hasn't proven to be yet.
 
Jeffh555 said:
Being able to vary the front overdrive based on terrain would be really interesting. I think there's systems that do that in road race or rally cars, but IDK.

This is something that might actually be easier to do if your front drive was electric.

I say interesting because who know if it'll be worth the effort/complexity until you try it. Horschel's 4ws car seems like it would be worth it, but hasn't proven to be yet.
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Not quite sure why he went 4ws in the first place. I get he is looking for an advantage, but rear steer seems out of place in racing. I think for a more dual purpose rig and not a racecar, then rear steer has more advantages, but at race pace I think its just a liability. If your doing IRS though, its real easy to add a steering system to it though.
 
I've never driven anything with 4ws, just armchair engineering here. I could see a handful of reasons it's worth trying.

Journalists seem to have good things to say about Porsche's and other sports cars with 4ws.

4ws rock crawlers are clearly more capable.

We're talking about a car that's never finished a race, any publicity is good publicity. The crabwalk jump seems to have gotten some good coverage for FOX and Nitto.

People I know with play cars with 4ws love it, because it's more fun. Remember, basically everyone racing is a hobbyist and fun is ultimately the reason they do it.
 
Jeffh555 said:
I've never driven anything with 4ws, just armchair engineering here. I could see a handful of reasons it's worth trying.

Journalists seem to have good things to say about Porsche's and other sports cars with 4ws.

4ws rock crawlers are clearly more capable.

We're talking about a car that's never finished a race, any publicity is good publicity. The crabwalk jump seems to have gotten some good coverage for FOX and Nitto.

People I know with play cars with 4ws love it, because it's more fun. Remember, basically everyone racing is a hobbyist and fun is ultimately the reason they do it.
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How many actual go fast race cars that race in the dirt or on pavement have 4ws? I can't think of anything except monster trucks and cone dodgers and do those really count? I'd think if it was the "cats ass" for racing we would have seen it in F1 or other forms of high end on road racing by now.

Play cars and race cars are two very different things. I'd love to hear Paul's reasoning for it and why he implemented it into his KOH car
 
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SLOWPOKE693 said:
I'd love to hear Paul's reasoning for it and why he implemented it into his KOH car
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Some people like the tried and true tech (Bomber and Miller), some people want to push the envelope (rear TTB, rear steer and other special cars).
Horschel never really liked anything simple.
 
Bebop said:
Some people like the tried and true tech (Bomber and Miller), some people want to push the envelope (rear TTB, rear steer and other special cars).
Horschel never really liked anything simple.
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Problem with the tried and true tech is that now that the bugs are being worked out of the "new tech" the tried and true stuff isn't able to keep up for much longer.

I also get trying to push the envelope but if what you do flat out doesn't work then trying the next idea would probably be a wiser choice than trying to polish a turd. I get the not liking anything simple part though, especially now knowing what he does for work.
 
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Hypothetically if Horschel got the bugs worked out and started placing well next season how long do you think till someone else tries it? That car wins a race and it'll get some attention for sure

If no one tries anything new it'll grow stagnant. We'll end up with a recipe for what works and no one will deviate from it. Hell look at the SA cars, it works but has been pushed so far it's at its limit. Now the IFS/IRS stiff is getting sorted out.
 
94toytruck said:
Hypothetically if Horschel got the bugs worked out and started placing well next season how long do you think till someone else tries it? That car wins a race and it'll get some attention for sure

If no one tries anything new it'll grow stagnant. We'll end up with a recipe for what works and no one will deviate from it. Hell look at the SA cars, it works but has been pushed so far it's at its limit. Now the IFS/IRS stiff is getting sorted out.
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There’s a twin to Paul’s current fancy car. I’m sure someone would quickly snatch that twin up with the tried a true method of a dump truck full of cash. :lmao:
 
Ghetto Fab. said:
Not quite sure why he went 4ws in the first place. I get he is looking for an advantage, but rear steer seems out of place in racing. I
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It adds more complexity, more moving parts and more failure points. Look at how many people bow out because of power steering issues just with a front steer car. Now you're doubling the failure possibilities.

Jeffh555 said:
4ws rock crawlers are clearly more capable.
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This right here! Having rear steer for the rock sections could potentially be huge, especially when you are trying to work your way through trail blockages. BUT, we've seen it time and time again, you need to know how to drive rear steer or it will get you into a bigger mess.


SLOWPOKE693 said:
At this point in the game I don't think IRS is even necessary. The IFS/SA rigs seem to be the best combo in KOH style racing at the moment and the simplicity of having a SA rear keeps the failure points to a minimum.
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It's been talked about for years. Look at the full suspension cars (IFS/IRS) out there now and it is not like they are stealing all the wins. Hell, look at desert racing, Class 1 is all about the unlimited full suspension rigs and they haul the mail, but the Trophy trucks with IFS and live axle are consistently the fastest.

Part of it is travel. You can set up a live axle rig to have way more travel than an IRS.

Another part is tire size. The TTs are running bigger tires, which make the holes feel smaller.

The TTs are bigger & heavier and continue to dominate. Maybe that's why we're going to seeing the bigger U4 cars dominate as long as they don't break and IF they get that formula down, they will be the TTs of U4.

94toytruck said:
Hypothetically if Horschel got the bugs worked out and started placing well next season how long do you think till someone else tries it? That car wins a race and it'll get some attention for sure

If no one tries anything new it'll grow stagnant.
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Eggs-xactery!
 
Tech Tim said:
It adds more complexity, more moving parts and more failure points. Look at how many people bow out because of power steering issues just with a front steer car. Now you're doubling the failure possibilities.



This right here! Having rear steer for the rock sections could potentially be huge, especially when you are trying to work your way through trail blockages. BUT, we've seen it time and time again, you need to know how to drive rear steer or it will get you into a bigger mess.




It's been talked about for years. Look at the full suspension cars (IFS/IRS) out there now and it is not like they are stealing all the wins. Hell, look at desert racing, Class 1 is all about the unlimited full suspension rigs and they haul the mail, but the Trophy trucks with IFS and live axle are consistently the fastest.

Part of it is travel. You can set up a live axle rig to have way more travel than an IRS.

Another part is tire size. The TTs are running bigger tires, which make the holes feel smaller.

The TTs are bigger & heavier and continue to dominate. Maybe that's why we're going to seeing the bigger U4 cars dominate as long as they don't break and IF they get that formula down, they will be the TTs of U4.



Eggs-xactery!
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The trophy truck vs class 1 debate is somewhat tainted by SCORE requiring class 1s to use traditionally weaker transaxles instead of allowing a transmission and ifs diff.
 
Treefrog said:
The trophy truck vs class 1 debate is somewhat tainted by SCORE requiring class 1s to use traditionally weaker transaxles instead of allowing a transmission and ifs diff.
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Companies could build a bigger/better transaxle.

The TTs are way past TH400s and it didn't stop them from developing new stuff to keep pushing the envelope.
 
SLOWPOKE693 said:
I'd think if it was the "cats ass" for racing we would have seen it in F1 or other forms of high end on road racing by now.
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www.racefans.net

Banned: Four-wheel-steering

Of all the exotic technologies to be banned from Formula 1 through the years, four wheel steering is perhaps be the only innovation to have been developed after it was outlawed.
www.racefans.net www.racefans.net
 
Bebop said:
Companies could build a bigger/better transaxle.

The TTs are way past TH400s and it didn't stop them from developing new stuff to keep pushing the envelope.
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Bigger transaxle doesn't make up for the poor unsprung weight ratio in the front/the lack of straight line stability from heavy rear weight bias. There have been a couple 1 cars with front engine/rear transaxle, but they weren't well funded enough to make a real effort. There is an AWD 1 car being built. I doubt it will be as effective as a AWD TT for the same reasons.
 
bdkw1 said:
Bigger transaxle doesn't make up for the poor unsprung weight ratio in the front/the lack of straight line stability from heavy rear weight bias. There have been a couple 1 cars with front engine/rear transaxle, but they weren't well funded enough to make a real effort. There is an AWD 1 car being built. I doubt it will be as effective as a AWD TT for the same reasons.
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Absolutely. The dynamics of a Class1 will never be as good as those from a TT.

I'm just saying that a weak gearbox isn't really why Class1s are slower.
 
I've got a question on this topic, how are F/R weight biases across all different classes across the spectrum?

I know U4 started super front heavy like all regular front engine vehicles, but have been pushing that weight further back with mid engine combos and spares hanging far off the back. Is the range like 45F/55R on vehicles like UFOs, Campbells, Horschels etc? How about Millers and Bombers?

From what I've gathered prerunners like to end up around 40/60 ish ballpark

Are trophy trucks in that same range? Have they started shifting weight back toward the front with the advent of 4wd?

Also how about class 1s, are they like 20/80 or something crazy like that?
 
Bebop said:
Companies could build a bigger/better transaxle.

The TTs are way past TH400s and it didn't stop them from developing new stuff to keep pushing the envelope.
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It's been a while since I have looked into it, but I think the issue was packaging bigger ring and pinion gears. Weaker ring and pinion means less power and smaller tires. Portals might be the thing that gets class 1s competitive again.
 
Treefrog said:
It's been a while since I have looked into it, but I think the issue was packaging bigger ring and pinion gears. Weaker ring and pinion means less power and smaller tires. Portals might be the thing that gets class 1s competitive again.
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Bunch of Class1s running 39s these days. They still slower than TTs.

TTs will never look that good though...

1709006443573.jpeg
 
Jeffh555 said:
www.racefans.net

Banned: Four-wheel-steering

Of all the exotic technologies to be banned from Formula 1 through the years, four wheel steering is perhaps be the only innovation to have been developed after it was outlawed.
www.racefans.net www.racefans.net
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From the article you linked:


"The major addition to this car was a hydraulically operated rear steering rack, which Moog electro-valves able to alter the steering angle of the rear wheels by two degree in either direction.

In an attempt to minimise any safety implications the hydraulics were designed to go into a preset ‘fail safe’ position in the event of failure, pointing the wheels straight.

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The system was also designed to be turned off and on at will, allowing the driver to run the car with a conventional front wheel steer set up if he preferred.

Patrese disliked the sensation of four-wheel-steering
And in the event that was exactly what drivers Schumacher and Riccardo Patrese did prefer, finding the four wheel steer set up added nothing to the car in terms of lap time. But it did, as far as Patrese was concerned, produce an unusual handling sensation."




It was tried and was of no use so even if it wasn't banned it wouldn't be used today.
 
Bebop said:
Bunch of Class1s running 39s these days. They still slower than TTs.

TTs will never look that good though...

1709006443573.jpeg
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Huh. Guess I need to do some reading on current state of the art for Class 1. Is trailing arm still the norm or has A-arm and multilink stuff like some of the 4400s and SxSs started to show up?

Class 1s and their dune going cousins will always look better.
 
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