semper

iirc before slippers, u'd set ur diff with a bit of slip (we're talking vague memories of running a Jrx2 in the late 80s here...) There's a gap between the torque needed to get the slipper to slip initially, and the (lower) level of torque needed for the slipper to stop slipping (something to do with static friction being higher than the friction of something slidding...). This makes it a poor form of traction control but good when u hit a rut or something...
I don't understand why limiting voltage (by only running 5 cells) works better than limiting current thru esc profile...?

AdrianM

iTrader: (4)

Yeah...We noticed the the many Cat 3000 like machines at the event. They say imitation is the most sincere form of flattery...lol!

We didn't really have a car to equip a formal factory team. We only decided to make the Cat 4000 in the last few months and there wasn't enough time to properly develop the car to a state where we would feel it could compete at the World level. We had (have) too many other projects in development to drop everything and fast track a Cat 4000 progarm in time for the event. The cars Simon and Rich were running are in no way, shape or form near what the final Cat 4000 will look like.

Cat 4000 development will start in earnest in September.

JoshR 85

HeY!!!


I've neva heard of this Cat 4000??? exactly wut is it and is there any pics that you may have???? whether its just 3d image or w/e???? thanx....


LaTa JoSh

Dirt-Racer

iTrader: (39)

Quiet Right Jack, that system was made and brought to the Race by LRP which had wires from the unit and were strapped onto the wishbones (for some reason) but it was deemed illegal at the event and was made so from then on. GM also makes a device but in smaller numbers.

Stu, the rules specify that you had to have 6 cells in the car, its that simple, it says nothing about using 4-5 cells of the 6 will be an infringment of the rules, more than anything it is interpreted has having a disadavantage simply because your working on a lower voltage. Traction control will have to be an added device (electronic wise) to aid a driver.

Dont wanna step on your toe here Adrian, but wasnt the XX4 first out with that design that Schumacher shortly sported after with the Cat3K

Oople you needs to read up what the slipper is for.

Arn0

Some pics??

Go there (http://www.oople.com/rc/photos/cat4000/), you'll found some!! Or here, the same in one clic (http://www.petitrc.com/view_news.php?id=2995)

Dirt-Racer

iTrader: (39)

[QUOTE=Arn0]Some pics??

Go there (http://www.oople.com/rc/photos/cat4000/),

Arn0, that link doesnt work dude!!

Anyways save you all the hassle Heres the PROTOTYPE of the Schumacher Cat4k... Pics are from OOPLE (Jimmy)

Arn0

Damn bracket!! It's working now

Dirt-Racer

iTrader: (39)

No worries m8, got there in the end...

One could argue that the Cat4k looks like a re-vamped Cat2K the concept or the design is almost identical, Well whatever you guys decide Adrian i hope the new car comes with the driveshaft plastic Blades and aluminium diff halves, those are by far cooler

Patriiick

iTrader: (3)

there is a huge difference between traction control and traction limitation.

A slipper is just a way to protect the transmission and somehow make sure some of the excess torque is dissipated to ensure smooth power delivery (as my friend oople rightfully pointed out)
Of course, running 5 cells was a way to bring down torque and speed in order to find the traction.

a genuinetraction control is a way to limit the rear wheel (in 2WD for instance) from slipping excessively in relation to the front wheels.
the front wheels thus have sensors on them to register their spinning speeds and the traction control adjusts the powering wheels to match to a certain extent.
Inherently traction control does allow for a certain amount of slippage to allow a small speed differential..
So traction control always means front sensors and some kind of sophisticated device.

Thus the two are completly different things..

tfrahm

iTrader: (2)

"Way Back"... Maybe 8 years ago? Schumacher showed up at the Worlds with TRUE traction control on their 2wd buggies... Small sensors glued to the hubs sensed wheel speed and fed that back to the electronics... Lord that was a long time ago, so I wonder if anyone has pictures of that setup?

Doughty

That was the LRP traction control system from

I believe Jurgen Lautenbach (Mr LRP) was using it on his schumacher

the way I understood it to work is that a sensor on the front wheels could limit the revs put to the rear wheels, if the differance in revs was high you were getting wheel spin and it would cut back some throttle.

as other people have pointed out, the only valid function of the slipper to to protect the tranny, there is too much sticktion to be able to use it to help put the power down, the hydradrive was designed to 'soften' the power application.

regarding using only 5 cells, everyone knows there is no substitute for voltage to make your car fast, why not get rid of some voltage to make the car driveable. this is not a reactive method of 'traction control' so I really see no problem with doing this.

S.Heath

iTrader: (21)

Taking power out of the car to make it more 'manageable' is done in other forms of motorsports. In the U.S., NHRA Top Fuel dragsters and Funny Cars routinely have less than full power tune-ups put on the engines to match the track conditions so that the driver doesn't smoke the tires in the first 300 feet. Horsepower is great, but it the track can't handle it, you don't need it.
My cousin told me of a race that he once won using this concept. The race was run on the wooden floor of a roller skating rink. He was entered in the modified class, and all his fellow racers were having a very hard time controlling the cars on the slick surface. He installed a closed endbell Mabuchi motor in his car and won the modified class by having a slower, but controllable car.

Dirt-Racer

iTrader: (39)

Rumaged through the old mags i had stacked somewhere and came accross the "THING" thats on topic here, TRACTION SYSTEM (LRP) quiet rightly was on Jurgen's Cougar 2wd car. As can be seen on the top plate a white coloured controller is the brains of the system which connects to the speedo mounted on the side of the chasis. From the looks of it, not only is there a sensor going to the front end but also for the rear end?.

Im not sure if schumacher brought out a system of their own but this was afterall mounted on a Cougar 2000 which is ofcourse schumacher, but like i mentioned earlier, GM also made a traction control system incorporated into one unit with the speedo, got one lying around somewhere but forgotten what the model was called.

Jack Smash

iTrader: (35)

The system will pick up when the rear wheels are travelling faster than the fronts by a certain percentage and reduce power until the difference becomes closer. Not good for trying to pick the nose up while in the air though.

Dirt-Racer

iTrader: (39)

Dunno bout you but im kindda lost with that statement