Skyfire

Stiffer shock with relatively softer springs? I understand that shocks affect the overall rate of weight transfer in the car. But would stiff shocks actually "over damp" the springs? How can I tell if this is the case? And what effect will it have if the springs were changed to something stiffer?

DustysA4

I don't consider myself a suspension guru by any means so point me out if I say something retarded...anyone?

Basically the shock controls the wheels movement up as you hit a bump. And then controls the spring bouncing back. You will be able to run sport dampers with stock springs, but you are not going to get the best performance from that setup. It will work though and will probably be the same if not a tad better than stock.

Basically when you want to upgrade the suspension you want the spring and shock to do different jobs. You want the spring to obviously support the car. And when you hit say a dip in the road, you want the spring to move fast, and the shock to move accordingly allowing the spring and damper to compress and absorb the bump quickly(not causing the car to jolt). A bilstein damper becomes STIFFER as it moves FASTER. So if you were to run that damper with stock springs you will feel more of that in your butt, since the stock springs are soft and move fast. Koni dampers are twin tube hydralic, so they aren't quite as harsh on the compression side so you don't pick up on the little things quite so much. In either case it's okay, as you just want to control the spring enough to prepare it for transitioning to the rebound movement. Then, once the spring is compressed you want the shock to control it when it bounces back. If you don't have enough rebound damping, then you will pogo around town. And if you have too much your ride will suffer again. Especially when hitting bumps DURING a turn. The spring will not get a chance to move back out fully and you might end up reaching your bumpstops. Rebound is actually very important when choosing spring/shock setup. Hence Koni makes all their sport dampers rebound adjustable only. Compression is a mixture of unsprung weights, car weight, and spring rate all in some formula that I'm too stupid to know....plus I'm doped up on hydrocodon so....*does the wisdom teeth removed today party dance*

Then there are things like turning, which are slower shaft speeds. You typically want the shock to have a firm compression during turns aiding the springs in keeping a flat turn. Racecars typically run linear rate springs instead of progressive springs also to keep the car level during turn in. So, with a soft stock spring on an aftermarket damper it will perform flatter than say the stock setup, but it is not going to sit quite as flat as it would with a better spring because the shock is doing more work slowing down the transition of the weight than is necessary because the stock springs are progressive and wussy=b There are some dampers that are valved Digressively, which basically means that during low speed damping, such as turns, the damper will be very FIRM, not allowing much movement. So you sit flat in turns, but once you hit a bump, digressive means that it doesn't increase progressively like most sport dampers out there. Instead it is hard at first, but once you reach a certain shaft speed it will open up and move faster, allowing the spring to do a lot of the work and basically not putting the jolts straight to your buttox.

So basically I'm in a drugged out ramble at this point, but all in all, like I said at the beginning(which means you didn't have to really read any of this), the setup will not be optimal, but it will be as good, possibly better than stock. Bilstein's and Koni's don't have digressive valving that I am aware of unless you have them revalved or buy a special setup that is valved that way. In a way they are both good. Bilstein is a monotube gas, valved very aggressive on the compression side so when you mate that with a progressive spring(like factory and most other aftermarket springs) it is going to be a good match somewhere along the movement giving you a decent setup no matter what spring you decide to go with. Koni on the other hand has a relatively softer compression(still firmer than stock), but instead pays more attention to rebound valving allowing you to match the shock to the damper more precisely. Personally I'd take a Koni damper over a Bilstein even if I was taking twice the drugs and drinking at the same time. But for someone who is not willing to do more than one install to get it set right, Bilstein may just be the shock for you. There are other shocks I'm sure, but they all suck.

Hope I helped and best of luck =b

Dustin

Skyfire

change the springs to something stiffer, like neuspeed sports or race. But if it's not gonna make that much of a difference over my current setup (I don't track), then I'm probably gonna spend the money else where. Would be much nicer if I'm mechanically proficient enough to do my own suspension installs.

BTW, how would larger diameter anti-sway bars affect this? If I added thicker front and rear sway bars, and while driving at highway speeds, the right side of the car hit a dip, will the car:

1) bounce/dip less when changed to stiffer springs
or 2) remain the same as before
or 3) ride becomes even more harsh.

thanks for taking the time to answer my questions.

DustysA4

I'm not a fan of swaybars personally. I would run nothing more than stock sport. BUT, if you were to add a sway in to the mix basically it ties both sides together. So with the stock springs being so soft you would gain some more flatness in the turns, but you would also gain a little harshness. Since when you hit a bump on one side, it is tied to the other and the entire rear will bounce a little more. With stiffer springs it will be more jarring. With H&R Ultra coilovers and a Neuspeed 22mm rear bar it was scary to hit a bump on the freeway. But for someone who is not wanting to spend a lot, a rear sway is a good fix just to get the car a little flatter. With a spring/shock combo or even your setup it's not going to be scary. The one thing that I do like about the Neuspeed sways(rear) is that they come with incredible reinforcement brackets. I'd like to have some of those just for my stock swaybar.

cuatrokoop

Aftermarket damper that is stiffer than the factory unit may lead to an overdamped situation in the system. Rougher, choppier ride would be the result, since the spring is being forced back to equilibrium too fast for its "k" value (spring rate). You may also wear out the damper faster, or blow it out if you bottom out the unit. Such is the case with running Koni "Yellow" dampers with the factory springs in an 80/90. Expensive shock to blow out...

A spring and damper should compliment eachother, its tough to get a road car to be ideal in all situations, which is why race cars tend to use 2, 3, and 4 way adjustable (compression and rebound, all the way to hi and low speed (of the damper piston) compression and rebound). Fine tuning the dampers for different situations, and different tracks.

DustysA4

I know Bils work with stock springs. Several guys have run them on the board and some have even tracked the setup. It's not ideal by any means, but it can handle it. The highly progressive nature of the Bilstein shock is definately going to hit a match with the stock springs somewhere along the line, which is the beauty of how Bilstein valves. They can cover almost every situation with one shock(to a certain spring rate of course).

Koni's are are a little weaker on the compression side so I can see someone bottoming out. And your right, that is one expensive damper. If I were to buy Koni's I would definately be sure to have springs going on at the same time.

Skyfire

That explained a lot, thanks!

cuatrokoop

"They can cover almost every situation with one shock(to a certain spring rate of course)."

Which is why the A4 w/Neuspeed Race springs (to me) feel funny at times, a little extra bounce here and there that the CQ doesn't really exhibit (its not perfect either)...The big difference may be due to the linearity of the springs in the CQ compared to the progressive behavior of the springs in the A4 (as well has having totally different suspensions).

DustysA4

What's CQ?....excuse me if it's obvious=b

cuatrokoop

aka 1990 CQ 20v, 2309cc 20v 5cyl, 1 of 1730 ever brought to the US, etc...

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