I want to lower my Cobalt SS/SC 1" front and 1" rear. What springs will do this? Ebach site says pro-kit 0" front .5" rear, Ebach says 1". Don't know what to believe anymore. Does anyone have pics of Ebach pro-kit installed on SS/SC?

 

I'd suggest looking somewhere else, in my thread I asked for people to post pics of cobalts on pro-kits and it's been days.... no replies.

 

Most poeple on this site have sportlines on their ss/sc. Pro kit may just even out, but I honestly think it wouldn't be noticeable at all. Unless you can find a pro-kit used, I wouldn't spend $220 just see a .5 inch difference in the rear.

 

If you want to see a difference in ride height, don't get the Pro-Kit, as they're pretty much an SS/SC springs with a different stiffness rate (but not much). They're more geared towards the base models. The Sportlines give a really nice drop without being ridiculous.

 

The pro-kit will improve handling on the SS/SC though... not everybody buys springs just to lower their car. I'm in Michigan and we get some pretty rough winters here so I'll probably go with the pro-kit springs over the sportlines.

 

The springs will have a slightly better rate to them......but it won't improve handling significantly......you don't get that just from a spring.

 

I didn't say it'll turn a cobalt into a lotus. I design suspensions for military vehicles for a living, I know there's quite a bit more to it than that. Springs are a VERY important component however, and the Pro-Kit springs matched to a set of Koni sport struts will be more than adequate for any street driving, and a good starting point for Solo II competition.

 

There's the key component......the Koni Struts. You could run the Koni's on the stock springs and it'll handle well too.

 

It handles well stock. It would handle better with the springs or struts. It would handle even better with both.

You are fooling yourself if you think the springs don't really matter and it's all about the struts. You need to match your spring rate and dampening if you want the best handling. GM did a pretty good job, all their testing wasn't a waste, they just had to compromise a bit to keep from making the ride too harsh to sell the car. The Koni struts are most likely a higher quality product than the stock struts, but they're not magic. If you set them too soft you'll have a bouncy ride (under dampened) and if you set them too firm it'll feel like you don't even have a suspension (over dampened). The reason aftermarket springs and struts work well together is because nearly all the springs will have a higher rate (stiffer) than stock, allowing you to increase the damping with the struts. They work together, neither one is the "key" component. I've had several business meetings with Koni and even they don't say it's all about the struts.

 

What I'm looking for is to lower the same amount all around to keep the same "stance". I don't care to have it evened out.

 

Another important factor for handling is lowering the center of gravity of the car.......the Pro Kit will not do this. You are relying only on the different spring rate......Eibach designs their Pro Kit as a compromise......it's for people who want a slightly lower car (ie: designed for base models) and still want a ride like the stock springs. I had the Pro Kit on my Mustang, it's not like I don't have experience with them. If you want the springs to be significantly better than the stock ones, the Sportlines are the way to go......quite a bit lower, and stiffer as well.

 

Why is that? The car looks much better when its leveled out slightly, and the car is nose heavy from the start so it can't hurt to bring the back down a little more.

You could always have custom springs wound, there are places that do that quite a bit.

 

sorry to but in this thread but. why do most kits lower more in the back of the cobalt than in the front? wouldnet you want the oppisite?

 

Lowering the center of gravity is not always good. CoG alone is not what gives you good handling. You need to make the distance between the roll-center and CoG as minimal as possible. If you lower the car to the point that the control arms are past parallel from the hrizontal place of the car, then you will be increasing the distance from the CoG and roll center, even though the car is lower to the ground. The car will then want to pivot the CoG around the roll center in a corner and will kill your handling. Most springs try to mask this by having high spring rates to allow minimal suspension travel.

Clear as mud??

Not really, your ass end will then have a tendancy to walk out on you (oversteer) if you have too much bias on the front end in terms of weight distribution.

 

Most people have no idea what this means, but it is correct. The best CoG is not always the closest to the ground. I haven't ran the numbers on a Cobalt to see if some lowering springs move the CoG past the optimal point, but it is quite possible to do so.

Also, the Pro-Kit springs with properly matched struts will do wonders for handling, my brother owned a Tiburon which we installed the pro-kit springs and struts (eibach used to make struts) and the damn thing felt like it was on rails.

Yes, racecars tend to be very low to the ground, but the suspension geometry is designed with this in mind.

 

exactly fwd's suffer from alot of understeer so if it would make over steer wouldent that be good?

 

I would think that most cars would have to be lowered to the extreme for the CoG to be all messed up as you say.......like when people cut their springs. What you are saying makes perfect sense, though.

 

One important point I forgot to mention sooner:

In nearly all stock vehicles the roll center of the rear suspension is higher than the roll center of the front suspension, which induces understeer (since the vehicle rolls centered about a line called the roll axis, which is a line connecting the front and rear roll centers). In the industry this is considered a desirable handling characteristic because less people will get themselves in over their heads if the car understeers before you totally lose traction. Lowering the back more than the front will lower the roll center of the rear more than the roll center of the front, which will lead to slightly less understeer than the stock suspension setup, which most car guys would consider a plus.

 

Good explanation - I wont post mine, you did a better job

If you raise the rear of the car, you will probably cause more understeer - BUT if you raise the rear and put in a stiff swaybar, or very stiff springrates, you are not allowing the torsion beam rear to load up. Once your torsion beam stops flexing, and your suspension stops compressing, you will get what is called "snap oversteer" and your ass-end will try to pass your front end. Basically, you are screwed at thos point.

YOu have to be very careful when fooling with your suspension. You need to figure out what you want to use the car for and find parts that work well together (springs, struts, anti-swaybars, etc) to provide you with the ride and handling charateristics you need.

 

ah word man i totaly get you so droping the back is compensenting for the stock rear being higher? right?

 

Sorta. There's nothing "wrong" with the way the back is higher stock, and it's actually done on purpose, but it's not ideal for optimal grip. The way it comes stock is purposely tuned to oversteer more than an even ride height suspension would, to give idiots more feedback before they totally lose control. It'll still understeer if you even it out, but it will do it slightly less than it does stock. A stiffer rear sway bar also cuts down on understeer. Good thing to have if you know how to handle it being neutral or oversteering easier than you're used to, but not ideal for all the hot heads out there. Usually in autocross if the course is real tight people will prefer larger rear sway bars so they can slide the back end around easier.

 

so i should. lower 2 and 2.5 rear and then get a sway bar. lol

 

If you have an SS, I don't think anybody makes springs to lower it that much. The Sportlines lower the base model about that much though if that's what you have.

In any event, Eibach springs (either Sportlines or the Prokit, sportlines are lower but both perform great) combined with Koni struts would be great for autocross. A rear sway bar is good too if you're looking for some oversteer... I'd recommend it for autocross on most courses but I'm not sure I'd recommend it for street driving. It should be fine, but totally unnecessary and it could make rainy / snowy driving a bit more exciting than you're looking for.

 

yea i got a base ls. i actualy would like more of a 3.5 and a 4 but no one makes em and i dont want to bag it. and yea i was thinking auto cross witht the accosinal drag here and there. then on the street. i think i could handle it i dont speed or anything. im a safe driver i only like to accelerate like **** evernow and then

 

Ok, wasn't sure because you have a blower in your signature. Dropping 3.5 and 4 would probably hurt your handling actually, and probably wouldn't be too good for your driveshafts either...

Just so you know, if you're running SCCA autocross changing the suspension will bumb you to STS where you'll pretty much be eaten alive by the cars built for the class. If you want to be competitive, you should try stock class first (if your car is stock right now).