Hey all,

I was driving on one of our main roads today doing the limit 100km/h. The rain was comming down pretty bad. Everything seemed fine as i took a gently curve as the road turned....Next thing you know I am doing a 360 and am on the curb on the other side.
Luckily no one was hurt and no accidents.

I have Hotchkis sways installed on my car (med/med - front/rear)
Could that have been the reason for my overstear...or good ol' hydroplaneing..or perhaps both.

I am wondering if I need to soften the set up or not.

THanks!

 

wow dude horrible
is ur car okay? and are you alright
where was this?

 

Good ol' Deerfoot!
I was heading south just past 32nd ave.
My GF and I are all fine, the whole thing was played in dream sequence for me. Luckily I was ahead of the general traffic so when I started to spin out there was no one in any of the other lanes...but they were comming!!
We ended up on the island that separates deerfoot and some merge onto it.

The G (which I was most concerned with ) seems fine. I jumped the curb on the back passenger tire but that is it. I drove it home with no issues. I will have to take a closer look tomorrow

 

wow that's a scary situation. Good thing you guys and the G were safe. I would like to know what the cause of that was.

 

They sways definatey stiffen up the suspension...but I don't think I was pushing the car that hard...but that + the weather may have contributed to the spin...I just want to know it softening up the suspension...(which defeats the purpose of sway bars) is warrented or overcautious.

 

Was the VDC on or off? And how is the condition of the tires - do they have lots of tread? Could have hydroplaned if there was enough water on the road.

 

All about the the font rear roll stiffness vs weight and tire road traction coefficient.

Race cars have adjustable rear sways to compensate for the rear weight change as gasoline is used up.
BMW [new 7 series] has a rain sensing rear sway bar stiffness that partially decoupled rear bar as the tire road traction declined when wipers turned on and progressive with their speed.

The point is tire traction declines from 0.9G in dry to 0.25G in wet or worse.

Setting up a rear roll stiffness JUST for dry is risky if you drive in wet conditions.

No easy and inexpensive way to make an easily adjustable [from inside on the fly] rear sway bar.

The use of wide softer rear tires adds some small protection against a sideways power on rear slide.

Easiest thing to do is set up roll stiffness ratios so that the front is 5-10% stiffer than weight alone would dictate.

Rear tires should never be allowed to drop below 5/32" tread if wet is a consideration.

 

VDC was on...but it never showed "slip" or cut power...I guess there was no time to kick in. Tires could be better to I guess.


Thanks Q45Tech, that is a lot of good info!! Gives me a better understanding of what is happening.