Hey Guys,
I'd like to know the process used to correct the car pulling on braking and to ensure the suspension is dialed in corectly for maximum performance and safety. Does anyone have a knowledge of suspension tuning and brake bias? I'd love to get into this myself, cause I know there is room for improvement in my car concerning these areas!

Thanks a lot,
RYan

 

I'm pretty good with suspension tuning but as far as brake bias, if you have ABS it's a bit hard to play with it.

Oh, one more thing, if your car is pulling to one side or the other, I'd check alignment and if its still a problem, take it back to the dealer. That should not be happening.

 

So, can you give me some guidance on either of the issues? I'd like to know what can go wrong with the suspension so I can check it out, furthermore, what causes brake bias? I have worked on brakes and the only thing I can think of is one piston sliding better then another in the caliper?

Please discuss!

Ryan

 

Brake bias isnt "Caused",its adjusted with a proportioning valve.Usually only from front to rear on race cars.

 

you would probably have to add valves to control the brake line pressure coming from the master cylinder. I have no idea how you could do this.

 

If you have an SS SC then the left or right pull you might be geting from time to time is do to the wide tires "Runing" in a gruve in the road. If it stops streaght in a parking lot or on a new road then there is nothing wrong with the car.

As for the suspenson there is not much out the for car at this time that you can "tune" so Im not going to go in to that.

What trim level do you have? base, lt, SS, SS S/C????

And how many miles are on the car?

Later

 

Why is this on SS/SC cars? Is it only our cars? I have that bad here in Hawaii, especially downtown. It's like riding on rails. In a smooth parking lot though, it's fine, so I know it's from the road. My pathfider, motorcycle, and my old ZR2 Blazer were all fine too. I wonder why that is?

 

It's not just the wideness of the tires but the tires themselves. The higher performance tires don't like to flex their treads which is why the tires tend to follow the road.

As for suspension tuning, I haven't touched my Cobalt yet but plan on going with the KW coilovers variant 2. This would allow me to corner balance my car and add a stiffer spring which should reduce body roll. Also the V2 part of it allows me to tune the rebound adjustment which basically is how stiff the shock/strut is. I have had great success with a similar setup in my GTI and loved the fact I could dial in a tad bit of oversteer in such a front heavy car. I realize though that this is a very expensive option and not many people can afford it. Whatever you do though, do not put lowering springs on yoru stock struts/shocks, you'll hurt performance and possible yourself.

After coilovers I'd suggest playing with a rear sway bar and seeing how the car handles after that. A lot of people on here put on the strut tower brace and say it works wonders but from experience, a strut tower brace on a FWD car isn't advisable unless you have massive amounts of oversteer, or can compensate for the understeer.

I think thats a good start to suspension tuning. I'd like to throw in there a couple things though,

1. each person likes their car to handle differently and each driver has their own style. Set your car up for the way you like to drive. For instance, I generally like the car to feel loose in the back, many people would rather prefer a bit of understeer (loose front end).

2. Try and only add one thing at a time on the car. You really need to re-learn how to drive the car every time you add something new. After maybe a month or so of some good runs you'd know which direction to go next.

3. Learn how to drive the car stock first. Before you start modding it, take it out to a local Auto-X and see how you can handle it. A car feels way different taking on and off ramps than it does throwing it around a course. You really get to learn the dynamics of your car and these types of courses tend to exagerate the bad qualities in the cars tune. You'll llearn a great deal about your car and yourself. This may help you answer the question above about how you like your car setup. I really wish more drivers on the road auto-x'd, it'd make the streets a bit safer.

As for brakes, the above posts are correct, brake bias is front to back. I'm not too sure but I dont think ABS cars have proportioning valves. As far as side to side adjustments, there really isn't such a thing. If you are experiencing this, it could be a bad piston in your caliper, brakes may need to be bled or theres a kink or crack in a brake line which I doubt. Again, something to take it into the dealer for.

If you have any specific questions about suspension tuning, let me know, I'd be more than happy to discuss it.