[undisclothesed]

What's the difference between Koni shocks and Bilstein shocks from a performance/daily driving standpoint? Why do some people choose one over the other?

Also as far as choosing springs, is it as simple as choosing one based on ride height or do they have to be matched to the shocks?

[SilverEmu]

As far as I know (I am on Bilstein Sport & H&R Sport):
Bilstein Sport - monotube, high pressure gas (a bit more expensive to manufacture, better heat management). They are not adjustable. Generally regarded as a harsher alternative, but can withstand more punishment and offer higher damping abilities. Bilstein also have the HD damper, that is supposed to be a direct replacement for the stock xi suspension, but I am not sure it can be used with lowering springs.

Koni Sport (Yellow) - twin tube, low pressure gas. As far as I know, they are considered easier to live with on a daily driving car. Single adjustable. Rears can come w/ external adjusters, so no need to remove the shock to adjust. Both TCK and HPA have come up with coilover conversion kits for them (offering height adjustability and high quality linear coilover springs - spring rates of your choice - a good step up in terms of performance).

If used in their factory form, both can be paired with either Eibach ProKit (linear) or H&R Sport (progressive) springs as their manufacturers claim they can work with lowering springs. During my research it came to my attention that the Eibach ProKit available in North America (#2092.140) is not specifically designed for AWD (our cars require slightly higher axle load ratings), while H&R has an AWD specific model. Generally, that did not prevent people from using the Eibachs and being happy with them. Consensus seems to be that Eibach lowers less and offers a more comfortable ride, while H&R is a bit more aggressive with the lowering and comfort.

I chose Bilstein and H&R because of the technology employed (Bilstein) and because I was set on using AWD specific products (H&R). I looked at the coilover converted Konis, but for my particular situation it was a bit overkill. Needless to say, I am happy with my choices. If interested, my notes on that particular setup are here.

[undisclothesed]

Thanks brother. That info is very helpful, and your car looks great!

Do you have any experience/opinions on linear springs vs. progressive springs?

Ironically even though the Eibach springs are linear the general consensus on this site seems to be that they provide a more comfortable ride than the H&R's.

[SilverEmu]

Thanks, it actually looks even better now, with the springs settling in nicely. I will add up to date pictures to my main post.

As I said, the look was not my primary concern, but I am happy with how it turned out!

The fact that the springs are linear should not have a direct influence on comfort, as far as I know. The linear springs compress uniformly and predictably, whereas the progressive springs are soft under low loads and get firmer as they compress - the problem is that, as I see it, the damper is only effective only on a portion of the suspension travel.

Clearly, the linear springs matched to proper dampers are the best, but like with anything else, you have to also consider your needs.

[AWD Addict]

Originally Posted by SilverEmu

As far as I know (I am on Bilstein Sport & H&R Sport):
Bilstein Sport - monotube, high pressure gas (a bit more expensive to manufacture, better heat management). They are not adjustable. Generally regarded as a harsher alternative, but can withstand more punishment and offer higher damping abilities. Bilstein also have the HD damper, that is supposed to be a direct replacement for the stock xi suspension, but I am not sure it can be used with lowering springs.

Koni Sport (Yellow) - twin tube, low pressure gas. As far as I know, they are considered easier to live with on a daily driving car. Single adjustable. Rears can come w/ external adjusters, so no need to remove the shock to adjust. Both TCK and HPA have come up with coilover conversion kits for them (offering height adjustability and high quality linear coilover springs - spring rates of your choice - a good step up in terms of performance).

If used in their factory form, both can be paired with either Eibach ProKit (linear) or H&R Sport (progressive) springs as their manufacturers claim they can work with lowering springs. During my research it came to my attention that the Eibach ProKit available in North America (#2092.140) is not specifically designed for AWD (our cars require slightly higher axle load ratings), while H&R has an AWD specific model. Generally, that did not prevent people from using the Eibachs and being happy with them. Consensus seems to be that Eibach lowers less and offers a more comfortable ride, while H&R is a bit more aggressive with the lowering and comfort.

I chose Bilstein and H&R because of the technology employed (Bilstein) and because I was set on using AWD specific products (H&R). I looked at the coilover converted Konis, but for my particular situation it was a bit overkill. Needless to say, I am happy with my choices. If interested, my notes on that particular setup are here.

I don't think I agree with the Bilsteins being harsher than the Konis, particularly given there was no mention of what setting the koni's were set to. I've driven on both. I found the fact that you can't adjust the koni's (rears) without putting the car on a lift pretty annoying as well.

I found the bilsteins softer than koni (on stiffer settings), and the H&R sports to be stiffer than the eibach. $0.02. The H&Rs are definitely lower, approaching slammed. Definitely less daily driver friendly (you'll be scraping a lot more, less friendly on bridge joints and small imperfections).

Also, the eibachs are not linear spring rates. They are progressive, as are the H&Rs
http://www.eibach.com/prokit.html
http://www.hrsprings.com/products/springs/

The "i" spring rates and "xi" spring rates are identical (as are the rear dampers). Based on this forum alone, I'd guess there are more xi owners running the Eibach Prokits (for i) than the H&R sports. Speculation, admittedly. There's no magic to H&R's xi springs, except they put the same product in a different box.

[SilverEmu]

Originally Posted by AWD Addict

Also, the eibachs are not linear spring rates. They are progressive, as are the H&Rs
http://www.eibach.com/prokit.html
http://www.hrsprings.com/products/springs/

That is what I thought too, and then I looked at this post here and there is a spring rate specified for the ProKit - isn't that a linear spring rate? Clearly, I am missing something.

Edit: Found the TUV Approval Document for the Eibach Prokit part numbers in Europe (different coding), available here and it states "Characteristics = lineare" (pages 4 and 5). You can also check the axle load numbers. The part numbers included are available in the European Eibach catalog. Confusing!

Originally Posted by AWD Addict

I found the fact that you can't adjust the koni's (rears) without putting the car on a lift pretty annoying as well.

Koni have 2 versions of the rear shocks. One that is adjusted as you described (shock has to be fully compressed and turned in order to adjust) and one that has an external adjuster (accessible via opening in the trunk). It also costs a bit more.

Originally Posted by AWD Addict

The "i" spring rates and "xi" spring rates should be almost identical. Based on this forum alone, I'd guess there are more xi owners running the Eibach Prokits (for i) than the H&R sports. Speculation, admittedly.

What I was referring to is the "permissible front and rear axle load". The Eibach spring kit version for 2WD has a max permissible load of 1090kg for front and 1135kg for the rear. The AWD version (available in Europe) has 1090kg for the front and 1200kg for the rear. Slightly different, hence my decision to stick to an AWD specific product - not exactly the same product in a different box .

Originally Posted by AWD Addict

I don't think I agree with the Bilsteins being harsher than the Konis, particularly given there was no mention of what setting the koni's were set to. I've driven on both. I found the fact that you can't adjust the koni's (rears) without putting the car on a lift pretty annoying as well.

I found the bilsteins softer than koni (on stiffer settings), and the H&R sports to be stiffer than the eibach.

In my post, I was not directly comparing the Bilstein Sport vs. Koni Sport in terms of harshness - I was just trying to say that, generally, the monotube design is a bit more performance oriented and has the potential for more aggressive damping than a regular twin tube design, which in turn, has the potential to be more comfortable.
I think it's fair to state that adjustability and ultimately valving can change that balance in any direction.

[AWD Addict]

Originally Posted by SilverEmu

That is what I thought too, and then I looked at this post here and there is a spring rate specified for the ProKit - isn't that a linear spring rate? Clearly, I am missing something.

You just have to look at them to know they're progressive, as confirmed by the product website. The link you posted did not list the eibachs as linear.

Originally Posted by SilverEmu

Koni have 2 versions of the rear shocks. One that is adjusted as you described (shock has to be fully compressed and turned in order to adjust) and one that has an external adjuster (accessible via opening in the trunk). It also costs a bit more.

You still need to have the car on a lift to adjust them. It's a threaded sleeve. Otherwise, you'll need to cut a hole above the rear mount in the trunk. That option is also $250, which is pretty obnoxious.

Originally Posted by SilverEmu

What I was referring to is the "permissible front and rear axle load". The Eibach spring kit version for 2WD has a max permissible load of 1090kg for front and 1135kg for the rear. The AWD version (available in Europe) has 1090kg for the front and 1200kg for the rear. Slightly different, hence my decision to stick to an AWD specific product - not exactly the same product in a different box .

Well the stock rear springs are identical between the i and xi. I don't know anything about hte Euro spec Eibachs, given I drive a USDM BMW. If the stockers are the same, then choosing the same spec for aftermarkets is fine.

As for the H&Rs, I think they are the same product in a different box. The drop is identical. Admittedly, they do not publish their spring rates.

Originally Posted by SilverEmu

In my post, I was not directly comparing the Bilstein Sport vs. Koni Sport in terms of harshness - I was just trying to say that, generally, the monotube design is a bit more performance oriented and has the potential for more aggressive damping than a regular twin tube design, which in turn, has the potential to be more comfortable.

You weren't comparing the only two options, right next to each other?

Originally Posted by SilverEmu

I think it's fair to state that adjustability and ultimately valving can change that balance in any direction.

I'm not sure it is. I've yet to read someone comparing them across the koni adjustability range with the bilstein. I thought you weren't comparing them though?

Pretty confusing series of posts...

[SilverEmu]

Originally Posted by AWD Addict

You just have to look at them to know they're progressive, as confirmed by the product website. The link you posted did not list the eibachs as linear.

Not sure the looks define the spring characteristics. The post under that link does not state "linear", but it posts a SINGLE rate, which defines a linear spring. The progressive examples posted under the same link show a range of rates, consistent with the progressive idea.

And clearly you did not check the TUV approval document that I included in my previous post. Have a look, it's quite enlightening - it actually lists them as "lineare". I personally don't care if they are progressive or not, all I know at this point is that the information on them is conflicting.

Originally Posted by AWD Addict

Well the stock rear springs are identical between the i and xi. I don't know anything about hte Euro spec Eibachs, given I drive a USDM BMW. If the stockers are the same, then choosing the same spec for aftermarkets is fine.

It might be, that was not my point. I was just trying to explain the reasoning behind my choice of AWD specific springs. You are assuming that despite having different part numbers, the H&R spring are the same, but there is no proof behind that assumption. The drop numbers don't have any relevance in this - even the manufacturers state they are approximate.
USDM or Euro specifics aside, the catalogue shows that there are differences between i and xi within the Eibach product range and that made me question the xi applicability of the only US part available and as long as there is any doubt about a particular application, I am not interested.

Originally Posted by AWD Addict

You weren't comparing the only two options, right next to each other?

That is just a compilation of my findings on the board. I did not pretend to compare the 2 as I don't have any personal experience with the Konis and I don't like to assume. Read my post again. I added the monotube vs. twin tube differences just to illustrate the 2 design paradigms. On the generic designs, even though the monotubes are regarded as more robust (note: GENERIC!!) in terms of damping, I believe the adjustability and the valving can make a twin tube stiffer. Still confused?

Originally Posted by AWD Addict

I'm not sure it is. I've yet to read someone comparing them across the koni adjustability range with the bilstein. I thought you weren't comparing them though?

Oh, but you just did. You said that the Bilsteins are softer than Koni on stiffer settings. Joking aside, I think the butt dynos should be cautiously considered as different people have different tolerance thresholds.

[AWD Addict]

Originally Posted by SilverEmu

Not sure the looks define the spring characteristics.

I am. Also, progressive spring rates are listed as one number because they're an average. Do you honestly know anything about what you're talking about?

Originally Posted by SilverEmu

And clearly you did not check the TUV approval document that I included in my previous post. Have a look, it's quite enlightening - it actually lists them as "lineare". I personally don't care if they are progressive or not, all I know at this point is that the information on them is conflicting.

Don't know what to tell you. They're 100%, absolutely not linear. There's nothing to be enlightened about. I posted the link to the company and product web page, and I've held them in my hands and looked at the coil. There's nothing to discuss. It's not a linear spring.

Originally Posted by SilverEmu

It might be, that was not my point. I was just trying to explain the reasoning behind m]y choice of AWD specific springs. You are assuming that despite having different part numbers, the H&R spring are the same, but there is no proof behind that assumption. The drop numbers don't have any relevance in this - even the manufacturers state they are approximate.
USDM or Euro specifics aside, the catalogue shows that there are differences between i and xi within the Eibach product range and that made me question the xi applicability of the only US part available and as long as there is any doubt about a particular application, I am not interested.

K You keep looking at the euro specs if it makes you feel comfortable. The usdm xi and i stock spring rates are the same. I'd advise anyone driving a us spec xi to run the eibachs with confidence because of that, and the dozens of reviews on this site. You go ahead and advise them aboutsome eurospec part number.

Originally Posted by SilverEmu

That is just a compilation of my findings on the board. I did not pretend to compare the 2 as I don't have any personal experience with the Konis and I don't like to assume. Read my post again. I added the monotube vs. twin tube differences just to illustrate the 2 design paradigms. On the generic designs, even though the monotubes are regarded as more robust (note: GENERIC!!) in terms of damping, I believe the adjustability and the valving can make a twin tube stiffer. Still confused?

The only thing I'm confused about is why you're still posting, particularly after you admit you have no experience, and the rst of the community's reviews disagree with you. This isnt a technical thread about monotube design. The OP is comparing two products, and you got the answer backwards when tryimg to sound smart.

If you admit you don't have any experience with what the OP is askng about, why are you still talking, and worse, wby are you advising anyone on the matter?

Originally Posted by SilverEmu

Oh, but you just did. You said that the Bilsteins are softer than Koni on stiffer settings. Joking aside, I think the butt dynos should be cautiously considered as different people have different tolerance thresholds.

Don't take my word for it, try the search button, or even better, maybe you could get some first hand experience on the matter before incorrectly advising a forum member. It's people like you that are more concerned with being right on the internet than actually knowing facts and helping people that make it hard for members to make a good decision, and feel comfortable making an upgrade. You'll even go to the lengths of saying the manufacturer is wrong so you don't have to admit you made a mistake.

Call a shrink, and please, spare the members looking for help and keep all your "knowledge" to yourself.

[AWD Addict]

Originally Posted by SilverEmu

That is what I thought too, and then I looked at this post here and there is a spring rate specified for the ProKit - isn't that a linear spring rate? Clearly, I am missing something.

Edit: Found the TUV Approval Document for the Eibach Prokit part numbers in Europe (different coding), available here and it states "Characteristics = lineare" (pages 4 and 5). You can also check the axle load numbers. The part numbers included are available in the European Eibach catalog. Confusing!

.

I encourage everyone to click that link. Tell me SilverEmu, are you looking at the limosine specs, or the 4cyl diesel?

[SilverEmu]

Originally Posted by AWD Addict

I encourage everyone to click that link. Tell me SilverEmu, are you looking at the limosine specs, or the 4cyl diesel?

Nope, I was looking at the 6 cyl. Limousine is sedan (spelled out as, surprise - E90) as opposed to touring (or wagon, aka E91). All there, in the wildly amusing TUV approval document. I will say it again: READ, comprehend and then jump at the keyboard. If that challenges you, banging heads on the forums is not gonna help.

The usdm xi and i stock spring rates are the same.

When was this topic being discussed?

There's no magic to H&R's xi springs, except they put the same product in a different box.

Solid, evidence-based statement. Ignorance is bliss!

OP was not looking for advice and I did not offer any, despite you pretending such numerous times. He was asking for reasons behind people's choices and this is what I offered, along with my sources. Why do you need to deviate, assume, assume again, disagree, laugh, insult, offer advice nobody asked for is beyond me...No, no need to explain, you did enough of that.

OP, I apologize for turning your thread into this mess. I will stay out of it, unless you have additional questions for me.