Monday, October 6, 2008

Managing understeers...

Ok, this is an interesting discussion i found while browsing through touge king's vast archive... :-p here's what they have to say about managing understeers... (copied it from the comments at touge king's blog at http://tougeking.blogspot.com/2008/05/lessons-for-us-touge-crash-for-others.html)

Anonymous said...

"Its not the fault of "understeer".

Undesteer is the product of the issue of the driver misjudging thier entry speed and the traction they have.Yanking the handbrake will NOT help if you already have too much speed. You will just throw the car into a 4 wheel slide and off the road.

In fact, i do not recommend it. If you understeer, usually you'd be better off just to hit the amco barrier. putting the car into a 4 wheel slide might cause it to flip... and not mentioning trying to correct for the e-brake induced oversteer might result in an even more dangerous snap oversteer.

Imagine this, you have no front grip. locking the rear will cause the rear to not have grip as well. If you do not have enough lateral force when you pull the ebrake, you are not going to be able to rotate.

So it depends, but from experience, usually it wont work. Handbrake induced oversteer only works very late into the turn, which means you are already generating significant lateral force for it to rotate.

In order for that to happen in the first place, you need to have enough front end grip to get there. As for camber settings, tail happy FWDs are fine if you are quick enough to correct for snap oversteer or oversteer on braking. Bottom line, you'd still be stuck in a craphole if you go in too fast.

Try this the next time you understeer. turn your wheel back to centre and trail brake in (to transfer weight to the front). Then when the front starts to bite, only then you start to turn again.This is the proper way we all learnt at track school and it works.

The logic behind this method, is that a car understeers when the front slip angle exceeds the available lateral traction of your tyres. Trying to reduce the slip angle will restore front traction. Most people make the mistake of doing the opposite. Most will instictively turn even more during an understeer event only leads to more slip angle and even less grip.

Notice some of them were at full lock and car wont turn? So for FWD drivers....Better start showing up at advance track school to learn these techniques..... hehehe

Han once asks how I could maintain such a high constant grip thoughtout a turn. This is because driving smoothly allows the car to settle on its suspension and maintain constant grip. Turning too quickly leads to excessive front slip angle and cause understeer. Braking too late is also an issue as you already know about the "traction circle".

JC."

azuri
said...


"I agree with what JC and erm said. My car has no ABS as well (plus i don't think that I like ABS at all - LOL).

adjusting the steering back to it's centerline and trail braking is another way to get back the traction on the front end before we have to turn again. After all it still rely on the speed before entering the corner, weight shifting, steering works and throttle control. This is actually has become my habits during touge sessions - Seriously i dunno wether it's a good thing or bad. (please light me up guys).

I have one video of me understeered in bukit tinggi downhill. it was a kind of high speed turn and my car speed was at around 120 - 130 km/h. I correct the understeer using my 'self thought' reflection and thank god i am safe. The speed drops from there to 60-70 km/h and i have to kick up again..

I will post the video soon.please help me light my way guys as understeer is a nightmare to most driver and the worse part of it, most of the time it occurs, it is unpredictable... "

Touge King said...


"Interesting discussion :)!

Jeremy's advice:"turn your wheel back to centre and trail brake in (to transfer weight to the front). Then when the front starts to bite, only then you start to turn again."

This is very good IF you have a wide run-off. That's the proper thing to do for understeer correction.

However, on the touge, when there is very little run-off, there is no time for weight transfer.

Bottom-line, don't over speed into a corner...God bless us all!"

So hopefully with that we all can avoid an untimely demise at the bottom of some dark ravenous abyss... X-p ARRGH!! The FC's in the workshop again T.T can't wait for the engine swap to be done with X-) gotta get some real touge dosage... X-)