Originally Posted by
urnotevenwrg2
This last weekend I had the pleasure of driving at a new track about an hour and a half away from where I live. They had the stickiest clay I have ever driven on in 28 years of rc racing. The dirt was so sticky that you could see exactly how much contact patch you were using. My outside rear tire would come off after a run pefectly clean, save for maybe 5mm of the inside edge. If I had added maybe a half degree of negative camber I could have moved the contact patch enough to make that tire come off with no clay stuck to it at all. Not that I would want any more contact patch with that much grip anyway. The working patch of every other tire on my car was centered and even. Doesn't really sound like much of a geometry problem to me if I can use that much of the tire.
That's because you don't know how the camber curves are. Look how the tire is being used the fullest.
Ever wonder why 2.4" tires were ripped out of their beads? Where's why.
Originally Posted by
Robbob
Alright question and hopefully not derailing but theres lot of interesting talk in here about arm length.
So .....
Looking at that Dax front end picture it seems like the kingpin is moved closer to the arm hinge pin vs what the stock C' probably would be.
Buggies and stadium trucks kingpins are out farther then the hing pin so to me its short arm.
4wd and Touring cars have the hinge pin located farther out then the king pin ....
Why? I know 4wd has to clear the front cvd and all that but what is the tuning/geometry reason? Is it just the difference in the vehicles or could the 4wd hingepin/kingpin geometry work on a 2wd or vice versa?
If you are referring to the suspension on the tekin car that's no DAX front suspension, it's a type of pillow ball suspension using pan car suspension parts.
That's my focus on the front end, the 2wd cars don't have space and axle joint constraints so I'm choosing to have the kingpin centred in the wheel. Typically 4wd cars have to run larger scrub radius than 2wd cars because it's very difficult to package the axle joint and the wheel bearings. That works better on 1/8th buggies because there's more space and for the record I'm designing an upright that does just that.
Getting rid of the current scrub radius is one of the goals of this project, if zero or negative scrub that remains to be studied. Let me add that MercedesGP and RBR went with negative scrub radius on their 2017 F1 cars.