Front wheel slipping in track

[Wolf_Tm250]

Hello,

please help me understand more shocks/suspensions behaviour and issues... really find the engine to be way more simple !!!

Please look at this video:

http://www.youtube.com/watch?v=EEZVYDp2tXc

My car is the white Celica GT-four, turbo awd.
This was on dry tarmac with stock sway bars.

As you can see after 00:40, the white smoke is coming from my internal front wheel spinning out of turns !

It really seems that I have to solve the lack of traction problem...
the IDEAL solution would be to install a front LSD... but unfortunately it doesn't exists... because the stock front diff has the central INSIDE of it !!
So there are no aftermarket front diff available...

So... what do you think I could do on my setup to resolve this issue ?

FYI, I installed later bigger front and rear sway bars, but the front internal wheel lack of traction was even bigger !

Thanks in advance...

[Noob]

does that wheelspin occur when the turbo spools back up? Pretty late in the corner for it to be from cornering.

[Wolf_Tm250]

does that wheelspin occur when the turbo spools back up? Pretty late in the corner for it to be from cornering.

Yes sure...
what you see in the video is what I get when I open wot after the turns, and the turbo reach the max boost, but it's the same that happens when I open in the corners... the frint inner wheel begin to spin and the engine reaches the redline...

[Brian P]

What happens if you go back to the stock front antiroll bar, and leave the stiffer rear one?

[Wolf_Tm250]

Hi Brian,
yes... this is the very first test i need to do...
thanks

[Bubstr]

What you have is transferring weight as you corner. What I see on the first part of your tape is an oversteer. Rear is loose. Normally on rear wheel drive car, the basic fix would be to reduce the spring/ shock/ bar acumulated rate values in the end that slides to outside, or increase the rate values on the end that is getting grip.

With a 4WD you run into problems when you get too much body roll. It transfers weight off the inside front wheel on corner exit. This is why you see most good handling 4WD run very flat. This is combination of stiffer spring rates and lower roll centers. If you think about it there isn't as much advantage to transferring weight when you are driving off all 4 wheels.

Now it comes down to the tools your car has to change it's behavior. If you could lower ride hight, it may help. Higher rate sway bars can eliminate roll to some extent. Remember you need to keep a front to rear balance in total spring rate to eliminate over or under steer.

Remember when you lower ride hight it changes camber and has to be corrected to get best of your tire. The stiffer sway bar will actively lower ride hight in the corners so that end has to be corrected for using a pyrometer to check tire temps.

There are some tricks you can do with anti squat values but get some what complex and hard to do on a stock suspension. The ride hight determines your center of gravity and it moving will change anti squat values some.

When addressing any handling problem, always take the problems in the order they come. This means, starting on a straight stretch you first brake, then enter corner, then transition corner, then apply power on corner exit. The reason being that some of the first things can effect the ones that come after. When you enter corner and transfer weight to out side, you set the inside front wheel up to get poor traction as soon as power is applied, because as soon as you hit gas the weight will transfer to the outside rear and off the inside front. You want to minimize this as much as possible and still be soft enough to keep tires on the ground. (Wash board effect)

The spring rate of the sway bar and individual spring is important. They have the effect of adding together in the corners. If either is too stiff, you tire compliance will suffer. This is the shake you get in corners at times.

[Wolf_Tm250]

Thank you very much !!!