Hello everybody. Does anybody do trackdays or autocross

[garridob]

This is my first post but ive been lurking for a while. I own an ugly, loud and uncomfortable 98 Nubira that I use to do things like passing S2000s with pilot sports on the outside going round long sweepers. Am I the only one not doing a drag or dyno hero build? If not Id love to compare notes. If so, does that mean I get to be the sage master who writes the book on Daewoo handling? If so, do you have any idea how screwed you eill be taking my advice?

[exist3nce]

LOL nice first post.... I've been around here for a while (altho not as active these days due to a new project car). So it sounds like you are a handling guy which is cool. I have KW V3 coilovers and have been to a few track events, but am not really a true handling fanatic. I enjoy power and acceleration so much more haha and ofcourse tinkering with all the turbo stuff and electronics.

[garridob]

Thanks. I built my car as half science experiment for my middleschool kids, half autocrosser, half trackday rig and half secret tool for humiliating people with big pocketbooks and small skills. If you pay attention to the math that means my car is four thousand times cooler than a 612 Ferrari.

[Efratech]

Mine is coming back to life slowly again and plan to use it on trackdays more than anything, I used to drag race a lot before but i've fall for drifting and since this cant drift i may just enjoy it on trackdays.

[garridob]

Cool, what suspension setup do you run?

[Efratech]

Since it was kinda more difficult to get parts when i started with these cars, i had to make a "hybrid"

Im using Honda aftermarket springs on the back and some Corolla aftermarket on front, i had to cut one "round" of the spring to get it lower enough on the front, but it handles nice and its not bumpy.

[Efratech]

Its good for daily use but on track it has a lot of body roll since it had stock shocks.

[garridob]

I've got a pretty significantly different rear suspension than you, I think. Your car has a torsion beam setup, right? For body roll, the biggest thing I would suggest, or at least the thing that has worked best for me, is to keep the car relatively close to stock ride height, particularly in the front. This will have a lot of benefits besides body roll.

Let me explain the body roll part. The amount of roll a car has is a function of g loading, CoG (which you can't do a whole lot about), roll centers (which you can do a whole lot about) and mechanical stiffness (swaybars plus springs). When you lower a strut car too much, the roll center drops much farther than the COG and the roll couple (distance from CoG to roll center) grows. This increases the distance of the roll couple and increases the amount of body roll for any given g-force load.

Over-lowering also has a bad effect on the camber curve. If the control arm is lower at the frame mount than at the knuckle, the car will gain positive camber in roll. This means that the car will really roll the tire onto its sidewall badly. On the other hand, if you keep the car at close to normal ride height, the suspension will gain negative camber under compression and the tire will do a better job keeping the contact patch on the ground.

If you really want a killer handling car, I have some suggestions there, too, but my methods are neither conventional nor well suited to comfortable cruising. They are, however, very well suited to track days and canyons.

[benzino]

I would like to hear your suggestions

[garridob]

I would like to hear your suggestions

For a pure track build I would go for 12kg/mm springs front with a moderate drop in ride height and the most aggressive rca's you can find. I would ax the swaybar and run as much caster as possible. If you dont have a bar, you wont need as much cqmbr, which is good for braking and accelleration. 2.0 degrees negative has served me well and my car is bigger than yours.

For the rear, Id need to know if you have struts ora torsion beam. For struts I would go to about 15kg springs with no bars or a very small bar you can adjust. The strut rears Daewoo used were designed to toe out slightly on compression so I would set zero static toe. The strut rears also have very high roll centers. This has caused a jacking condition on my car and required q .76 inch drop to cure. As long as you dont get jacking, that high roll center is basically free roll resistance and a better camber curve.

If you have a torsion beam I would go with a spring that gets you a wheel rate around 9kg. Not sure what the motion ratio is on a Lanos. I would combine this with a lower front ride height and a big, adjustable bar in the back.

The torsion beam, unfortunately, causes a stream of compromises in both the front and rear. If you wanted to be really hard core you could make a solid rear with a panhard bar (look under most minivans to see what I mean) wnd then jack up the rear roll center. Do that and you can pretty much just use my strut spring rates and no bars.

For street tires a 9kg/9kg setup on struts is working very nicely for me. No bars, btw.

[benzino]

Very interesting mate, thanks for sharing!

Yeah, lanos has torsion beam rear and with no rear sway.
I currently have h&r springs -35mm and stiffened kyb shocks.
Much better than stock, but still a fair amount of roll. I was thinking a rear seat bar would have a pretty good affect on reducing the amount of roll... Either that or stiffer shocks.

[garridob]

Very interesting mate, thanks for sharing!

Yeah, lanos has torsion beam rear and with no rear sway.
I currently have h&r springs -35mm and stiffened kyb shocks.
Much better than stock, but still a fair amount of roll. I was thinking a rear seat bar would have a pretty good affect on reducing the amount of roll... Either that or stiffer shocks.

Shocks wont lessen the amount of body roll. They will help turn in, but not the final roll angle. I think your setup is probably too low and too soft. Tell me if Im wrong, but Ill bet your car rolls hard in the front and bottoms out the front outside suspension. Ill bet you get sort of unpredictable levels of front grip. Ill bet hard driving absolutely lunches the outside front tread blocks.

If I was you Id disconnect the front bar, invest in a rear bar and go get some custom springs. Springs are pretty cheap, or at least they are in Korea. Ask for 10 mm drop and 9kg front, 6kg back springs if you are willing to tolerate a firm ride. If you want more comfort keep the stock front bar and go with 6kg front, 4kg rears with a 10mm drop. In either case I would use the biggest rear bar I could find.

If you have access to a decent fabricator, go to the junkyard and pull a front bar off something like a motorhome. Just get something where the transverse section is pretty much flat. Take it to your fabricator, cut it to the proper width and put splines on each end. Attach these splines to a long lever extending to your torsion beam and put many holes in you lever arms for mounting adjustability. Get long swaybar links and adjust to your hearts content.

[benzino]

Grip is excellent and progressive, and the tyres are fine and are wearing evenly... I have no bottoming out at all... It may be too soft, but the height is perfect.

It feels like all the roll is at the back. I'll try and find the rate of the springs I have. All I know is the fronts are linear and the rears are progressive.

[garridob]

Do you have a really big front swaybar? If the factory Lanos bar is anything like the factory Nubira bar, the answer is yes.

Does your car understeer a lot? If it's rolling at the back and not at the front, and with a 35 mm drop, it almost has to understeer unless you've got some sort of funky tire combination or geometry.

When I said "lunching the outside tread blocks" I meant under really hard driving. Like if you do autocrosses.

Here's a demonstration of what I'm talking about with regard to roll centers. http://www.modified.com/tech/0508_sccp_ ... to_02.html

You might want to check if your control arm is higher at the chassis or at the knuckle. If it's higher at the knuckle that means your car is gaining positive camber under roll, which is progressive but bad for grip. If it's higher at the chassis, that means your car is gaining negative camber under roll, which is better for grip and tail out antics.

Here's what I mean. Notice how the camber curve gets worse and worse the more you lower an STI.

http://media.photobucket.com/image/camb ... ummary.jpg

Also, just so nobody accuses me of stealing, the setup stuff I'm referencing is based about half on my own experience and about half on Steve Hoelscher's championship winning autocrossers.

[garridob]

Just realized something. You lowered the car not very much at all. 30/40 mm. I had it in my head you did 3/4 inches. Ignore everything I said about over lowering. You are fine on ride height and I need to step away from the crackpipe.