BruceWarne

Mycroft, I read this in an article (yours?) ("On all fours", http://www.jkwebdesign.co.uk/lexusclub/onallfours.htm )

Could you please explain to me what this means? ?Especially the part about "Hysteresis Loop". I think understanding of this subtle concept might increase my (on the limit?)driving ability significantly. Layman's terms, please, I'm not too hot on technical jargon.

Thanks!

Jay m A

iTrader: (2)

I'm not sure but I'll have a go since noone else has replied.

I don't know technical jargon either so bear with me. Basically when a car starts so drift / slide round a bend its exeeded the tyres (certain type of) grip. lets just say that at 1.00 G cornering force the car is at the limit of grip. At 1.01 G the car starts to slide. If you then back off to reduce the cornering force back to 1.00 G instead of the car gripping again, it still continues to slide. Lets just say that it only regains grip from a slide at 0.95 G. I think the basic differences in static and dynamic coefficients of friction is a way of understanding why it happens. Anyway this I believe is the hysteresis loop, ie going from grip to slip is at one force, and returning from slip to grip is at another force, a hysteresis of grip.

Feel free to shoot me down in flames

BruceWarne

Thanks. That's how I understood it myself.

But how would this differ from dry to wet...? Is the difference between static and dynamic COF larger for wet tyre/road interface, than for dry tyre/road interface...?

Jay m A

iTrader: (2)

Dunno.

The way its phrsed may be relative to a std road tyre ie remarkable levels of dry grip but poor levels of wet grip. Or it could be talking about progressiveness of grip breakaway, as in its quite talkative in the dry when its hot and sticky, but when cold and wet its more of an on/off switch.

BruceWarne

bttt