Finally Have Some Coil Spring Rates (Neuspeed & Eibach) for our Quattros.

[Arnolds64]

After Searching here and it seems everywhere and not being able to find Spring Rates which is surprising. VW Vortex has a Sticky about it. Maybe this should be a Sticky too? These are for the street type Sport Coils for our Cars. I did a little research and called Neuspeed and Eibach. I am trying determine how to get the ride I want. Yes I want good handling but do not want to get beat up daily either.

Neuspeed Sports- Front - 230 Linear * Not really a Progressive according to the salesman in that the light close bunched up coils that look like a progressive off the car when install on the car as he said only to take up space. Therefore the spring becomes Linear.
Rear - 400 - 630. * He said that the progression is from the large Bump Stop not the spring.
I have these on my car and they are fairly stiff. Lower the car well, not to low or just right for my taste. Supposedly only 1.2" all around but looks like more. Handles crazy good but a tad stiff for me and with Koni Yellows. If you want handling wow with at tad of oversteer we need.

Eibach Pro Kit- Front - 154 Linear * They are Open or same distance between all coils or a true Linear spring rate.
Rear - 359 -999 Progressive Rate. * These from the way they look are a real Progressive rate in that they are an Open coil but look to change only slightly or bunch up slightly. Bump Stop most like helps send it high on Compression as well.
I would imagine just by the way they look they would give more range of motion giving a more compliant ride. We will see as I am going to try these and see the difference. I know they will not sit as low only .1" different but I am looking for a smoother ride as this is my daily and the wife is biotching every time she rides with me. LOL!

Hopefully I can help you all here determine what fits your needs. If someone has H&R's and any others chime in if you want.

Another tidbit that I have read here is how some people will say it is only the shocks that determine the ride quality. Well that is dead wrong folks. I had 2 Mustang GT's. One with Ford Racing C's that are 650# Linear Front and 300-400 Progressive rears with Monroe Sensatracs. Another with Eibach Pro Kit which were Progressive frt.-420-530 / Progressive rear- 200-300 and with Tokico 5 way adjustable shocks. Running the Tokico's at 3 which is Probably close to the Sensa Trac valving the Mustang with the Ford Racing C's Road better and handled as good. So the springs made a big difference in ride quality. All depends on the cars architecture sure but experience of the seat of the pants is the best test.

[20v master]

The shock being matched to the spring is why people say the shock determines ride quality.

[Arnolds64]

Well yes that is true about matching things up but I guarantee when I switch the springs out the ride characteristics will be different keeping the same shocks. Of course with the Koni's I can adjust them. Leaving them at the same setting and when they will not ride the same and that means the springs make a difference. So they both separately make a difference. I understand this after trying to use the OE Spectrum Monroes with the Neuspeeds. Not good at all. Yes you have to match up for the speed of the rebound of the shocks when they are stiffer so they will ride half way decent.

[20v master]

Well yes that is true about matching things up but I guarantee when I switch the springs out the ride characteristics will be different keeping the same shocks. Of course with the Koni's I can adjust them. Leaving them at the same setting and when they will not ride the same and that means the springs make a difference. So they both separately make a difference. I understand this after trying to use the OE Spectrum Monroes with the Neuspeeds. Not good at all. Yes you have to match up for the speed of the rebound of the shocks when they are stiffer so they will ride half way decent.

Of course changing to a spring with a different rate with no other changes is going to ride differently. But if the shocks were matched to the springs before and after, then you wouldn't tell a difference in ride quality. Handling yes, but harshness no. Also, just because you have adjustable shocks doesn't mean they adjust to the specific spring rate of the spring you're using.

[DougLoBue]

Any KW V1 varriant (HPA SHS or ST's) will net you some comfort in my experience. Soft springs, soft struts. If you think Neuspeed springs handle amazing you'll probably think V1's are incredible as well.

Sidenote: as long as you don't slam the sh!t out of them V1's will be comfortable. If you go so low there is no room for suspension travel of course it will be uncomfortable.

[Chickenman35]

Of course changing to a spring with a different rate with no other changes is going to ride differently. But if the shocks were matched to the springs before and after, then you wouldn't tell a difference in ride quality. Handling yes, but harshness no. Also, just because you have adjustable shocks doesn't mean they adjust to the specific spring rate of the spring you're using.

I'll respectively have to disagree with that. As spring rate is increased, spring frequency increases. Spring frequency rate defiantly definitely affects the ride quality including harshness. Ride quality is a function of BOTH spring rate and shock rates.

The shock absorbers purpose is to dampen the spring oscillations. It is NOT to support the vehicle. Unless you have double adjustable shocks, the rebound rate is the main force that is adjusted most on a single adjustable shock ( Compression may be adjusted in conjunction, depending on manufactures design..but not nearly to the same amount as rebound).

I'll take an example of a car that I've had lots of experience tuning. My 1986 Camaro. I've run this with a variety of spring rates ( For Autocross, Hillclimbs and Road Racing. Same shocks throughout. Koni's set on full hard with 600lb/in front springs ( This setting was actually over damped for the 600 lb/in spring. ) same Koni's set on full hard with 850lb/in front springs. The 850 lb/in springs were way harsher for daily driving that the 600lb springs. ( Wheel rate at the front is usually about 47% of spring rate on these cars )

Even better comparison. Most top 3rd Gen cars running in Autocross run a soft rear spring to maximize forward bite ( The beam axle and Torque arm suspension allow us to do this ). 175 lb/in to 200 lb/in Rear shocks are usually run pretty soft as well. Usually no more than a couple of clicks from full soft. Rear wheel rate is 1 to 1 because of the beam axle.

Increasing rear spring rate from 200 lb/in to 225 lb/ in made my setup almost un-driveable it was so loose. And you could definitely feel that the back end was much harsher and you noticed bumps in the road much more than with the 200 lb/in springs. 25 lb/in difference was not enough spring rate change to require more rebound to be dialed into the shocks. They still had sufficient dampening to fully control the 225 springs. But you could definitely feel the ride difference between your butt cheeks.

You can look at it this way: Spring rate is a course setting for tuning both handling and ride quality. Shock rate ( rebound and compression ) is a fine setting for tuning handling and ride quality. Once you are in the ball park with spring rate, then you fine tune with shock settings. And ride quality will always be affected by spring rate.

[Chickenman35]

Short version of above post:

Which came first? The chicken or the egg?

[Marcus_Aurelius]

^^^ short answer, it's the chicken!

Harshness, which is not a term that I like at all when refering to suspension, is mostly a function of the shock's ability to control the choosen spring rate within a range of natural frequency for a platform. Noticed I said mostly, the second factor, with a lesser impact, is at what natural frequency that said spring rate is acting in concert with the bar rate and tire stiffness to make the final wheel rate. I am more in agreement with Adam here because even when the spring are what supports most of the car's weight (minus the unsprung weight), the shock's valving is what controls the rate and speed at which any spring motion is transferred.

Let's say hypothetically that shock valving for comfort and a bit of sportiness on production cars in general is at 50% critical damping (linearly on both compression and rebound). If you were to increase the spring rate X percent without doing any change to the valving that was set at that 50% critical damping, it would feel a lot harsher because the shock wouldn't be controlling the forces at that same magic number choosen for comfort. So essentially it's the shock more than the spring.

This brings me to the next point of chassis natural frequency. There is a certain range of natural frequencies that a street car is most happy and comfortable in. Depending on the manufacturer, it is around 2 Hz. Increase the wheel rate (spring+bar+sidewall stiffness) pass 2.5 Hz and things get bit "harsher". Not because of the shock's inability to control the forces in action, but simply because, for the particular chassis, the wheel rate/natural frequency ratio is to high to keep the contact patch on the ground (it could be bumps, road undulation,junctions, potholes etc.).

In conclusion, the harness of the ride is mostly the shock (but within a certain natural frequency for the application). When the regular Joe just increases the spring rate, the harshness felt is a result of the shock no longer valved to control things properly. In Chickenman's case, I believe he may have have been pushing the limits of natural frequency for his application, but who knows (I know not to push my luck pass 3 Hz in the back or it's spin city on any track or autocross course... and unles you can bring some serious Aero downforce, there is a limit on production cars).

[l88m22vette]

Essentially, all this information also explains (ends?) the spring/shock vs coil-over debate, s/s combos can be matched to a spring, but coil-overs are specifically matched, and is part of why they are ultimately better.

I have Eibach springs and dwelled on FSDs, but instead am going to go with PSSs once I sell the springs and collect the other misc suspension stuff...(thank you "forum" advice )

[Marcus_Aurelius]

Essentially, all this information also explains (ends?) the spring/shock vs coil-over debate, s/s combos can be matched to a spring, but coil-overs are specifically matched, and is part of why they are ultimately better.

Well, kind of but not always!

Coilover companies also manage to screw it up royally (or maybe just cheap out on cost to make a higher profit on uneducated buyers). Just like the "shock and spring" combo not matching, you'll find that most, if not all, cheap entry level coilovers are leaving a lot of questions unanswered. First, they arbitrarily pick spring rates that doesn't match the platform (the real truth is they have a narrow set of spring rates range that they assign to their entire line up regardless of what car they're for). Secondly, they use subpar shocks with questionable valving. This all adds up to make a product that's only good at lowering the car but is as bad, if not worse than OEM (most people don't realize that stiffer doesn't necessarily means better handling).

Let's take the 225 TT for example. The front geometry basically has a 1:1 motion ratio, while the rear is a bit under 0.7:1 motion ratio. What this means in a nutshell is, a the front springs of 1000 lbs has a 1000 lbs effect on the wheel rate; but in the rear a 1000 lbs spring only has 700 lbs of effective rate at the wheel (1000 lbs X 0.7 motion ratio). Compounding this with the fact that the non-steering axle (rear) is trailing and needs to be speed up to have the car settle as close to simultaneously as possible. A coilover truly designed with R&D for the TT, will have a much stiffer rear spring rate to accommodate the platform's suspension geometry. Unfortunately, it's rarely the case and you'll even find coilovers that are popular in the market with stiffer front spring rates (I won't name brands because vendors may get offended and Vortex may want to drop the hammer on me). When you have bad/wrong spring selection and you put them on poorly valved, low quality shocks, you have a blueprint for horrible handling. Luckily, there are good choices out there if anyone cares to do their homework. The PSS/PSS9 (essentially the same) are very good and you will have solid handling with them. H&R also did their homework on some of their offerings and use the same Bilstein shock as the PSS/PSS9 with proprietary valving and more thought out spring rates for the platform. Besides that, you most likely have to go AST, KW clubsports, Ground control AD, Motons (yes they make as set for us) to get good performance.

In conclusion, good coilovers are a better choice, but poor coilovers can be below stock in terms of true handling. Pick your poison!

[Arnolds64]

Hey I guess I hit nerve. All I can tell you is that I learned that what I thought was a Progressive Spring really is not once the car is sitting on the spring. So the rear has about 2.5" travel and a lot of it is on the bump stop in the rear. The Front also has what become like 3 Dead coils which as well cuts down on spring travel. I think the Linear springs with the Eibachs will be much more to my liking being that they look to have more spring motion or travel?

[Chickenman35]

Hey I guess I hit nerve. All I can tell you is that I learned that what I thought was a Progressive Spring really is not once the car is sitting on the spring. So the rear has about 2.5" travel and a lot of it is on the bump stop in the rear. The Front also has what become like 3 Dead coils which as well cuts down on spring travel. I think the Linear springs with the Eibachs will be much more to my liking being that they look to have more spring motion or travel?

Not really hit a nerve...we just like to discuss chassis setups. And it is a very complex and interesting subject. Everything interacts with everything else.

I've never really liked progressive springs. They are difficult to figure out what your actual overall spring rate is. I much prefer a linear rate. But that's just me...

BTW, if you lower the car, you should shorten and reshape the bump stops. Running on bump stops is generally not good.

[Marcus_Aurelius]

I agree with Richard, progressively rated springs are an epic fail whenever handling is a concern. Shocks usually have a hard time taming the non-linear range of forces exerted with any sort of consistency (think trying to nail an erratically moving target with consistency). On top of that, we have a very short rear spring length of 4". So, dead coils and riding on bump stops is inevitable with the structure most progressive springs, even the barel designs can't cut it in less than 4" of spring travel.

I suspect that the high terminal rate given when the manufacturers were called, accounts for the first few mm of bump stop rate. The 399-999 listed is fishy as they usually only progress 100-200 lbs in rates

[Arnolds64]

I agree with Richard, progressively rated springs are an epic fail whenever handling is a concern. Shocks usually have a hard time taming the non-linear range of forces exerted with any sort of consistency (think trying to nail an erratically moving target with consistency). On top of that, we have a very short rear spring length of 4". So, dead coils and riding on bump stops is inevitable with the structure most progressive springs, even the barel designs can't cut it in less than 4" of spring travel.

I suspect that the high terminal rate given when the manufacturers were called, accounts for the first few mm of bump stop rate. The 399-999 listed is fishy as they usually only progress 100-200 lbs in rates

Yeah the guy I spoke to said he had to get this information from Germany as the front was the only one listed for the Quattro he had. He did sys the bump stops were the high side.

I also wondered about cutting the bump stops to get some more rage of motion for the suspension. I know that on my Mustang the Ford Racing C springs had you cut them in the install instructions. It just seems that I am riding them very early on compression even over dips. On smooth roads though it is really amazing though. Left the traction control on the other day, hit a corner and it just ripped through it then with the waste gate spring and the Mad Max DV the acceleration was instant. It just does not get better than that. LOL!

[Marcus_Aurelius]

hit a corner and it just ripped through it then with the waste gate spring and the Mad Max DV the acceleration was instant. It just does not get better than that. LOL!

Now get a set of Bilstein PSS and all you'll want to do is take corners and power out of them! They really aren't that bad and will not beat you up. It's just a suggestion, but I know once you start thinking about it, the damage is done (I can smuggle them to you as the usual "Madmax add package" for Christmas).

[20v master]

I'll respectively have to disagree with that. As spring rate is increased, spring frequency increases. Spring frequency rate defiantly definitely affects the ride quality including harshness. Ride quality is a function of BOTH spring rate and shock rates.

I forget that you have to balance your posts here from over the top technical to way dumbed down to appease everyone. My statement was in the context of the OP, regarding off the shelf "sport" springs for our platform, not custom linear springs with 40% difference in spring rates between the two. Yes, I'm aware shock and spring both affect ride quality (along with tire, bushing age/condition, geometry, vehicle loading, etc etc), but do people think a car is going to ride "much" differently on Neuspeed sport springs with Bilsteins Sports over H&R sport springs with the same shocks? I would hope not, but then again, most people get caught up in brand name, just want the look, and don't understand mx(dot)^2 + bx(dot) + cx = F(x), much less a steady state bicycle cornering model. I need to get the laptop out and create some Pacjeka curves for the TT to develop true understeer gradient, but that wouldn't help anyone but me unless they were running the same tires and pressure, spacers, suspension, sway bar setup, etc.

[Chickenman35]

I forget that you have to balance your posts here from over the top technical to way dumbed down to appease everyone. My statement was in the context of the OP, regarding off the shelf "sport" springs for our platform, not custom linear springs with 40% difference in spring rates between the two. Yes, I'm aware shock and spring both affect ride quality (along with tire, bushing age/condition, geometry, vehicle loading, etc etc), but do people think a car is going to ride "much" differently on Neuspeed sport springs with Bilsteins Sports over H&R sport springs with the same shocks? I would hope not, but then again, most people get caught up in brand name, just want the look, and don't understand mx(dot)^2 + bx(dot) + cx = F(x), much less a steady state bicycle cornering model. I need to get the laptop out and create some Pacjeka curves for the TT to develop true understeer gradient, but that wouldn't help anyone but me unless they were running the same tires and pressure, spacers, suspension, sway bar setup, etc.

I feel the first sentence is rather insulting and unnecessary

Rest of post is of course correct...but you could have said that ( Neuspeed vs HR vs Eibach etc ) in the first response instead of using a " Generality " which is incorrect. Of course springs with similar rates are going to Ride the same. It was the generality statement that I was responding to.

[20v master]

I feel the first sentence is rather insulting and unnecessary

Rest of post is of course correct...but you could have said that ( Neuspeed vs HR vs Eibach etc ) in the first response instead of using a " Generality " which is incorrect. Of course springs with similar rates are going to Ride the same. It was the generality statement that I was responding to.

I'm sorry you feel that way, but you're damned if you do and damned if you don't. I try to keep it simple since the engineers and techincal junkies in here typically go over the heads of most. The second you do that, you have another technical junky trying to nit pick anything you say as incorrect.

[Marcus_Aurelius]

I'm sorry you feel that way, but you're damned if you do and damned if you don't. I try to keep it simple since the engineers and techincal junkies in here typically go over the heads of most. The second you do that, you have another technical junky trying to nit pick anything you say as incorrect.

Ya better be on your toes! (especially you Adam)

[Chickenman35]

I feel the first sentence is rather insulting and unnecessary

Rest of post is of course correct...but you could have said that ( Neuspeed vs HR vs Eibach etc ) in the first response instead of using a " Generality " which is incorrect. Of course springs with similar rates are going to Ride the same. It was the generality statement that I was responding to.

Well... I might have misinterpreted what you intention was. I took it as directed at me...which may not have been your intention. Sorry if I took it the wrong way. That's the danged problem with forums and e-mails. Sometimes what we type can be misinterpreted.....

Much better to sit down at the Pub and have a good technical discussion over Wings and Beer

[20v master]

Much better to sit down at the Pub and have a good technical discussion over Wings and Beer

Sounds like we'd get along just fine.

[babarber]

Sounds like we'd get along just fine.

I agree

[Arnolds64]

I agree

You know what I have found over all my gearhead years is things like "Max"arcus Arellius's most recent Home Depot spring mod to hold the Waste gate closed longer just fricken works in the real world. Just like me doing my own Port work and Chamber work on VW aircooled heads. I have people tell me that I would lose power on thesamba.com, a huge VW forum. This just because some CNC company dude says without extensive flow bench and perfect contouring of the port you are wasting your time. Also people telling me that a cam choice I wanted to use would unmanageable in the street. Well I can tell you for whatever reason my 2017cc bug would probably give my TT a run in the quarter if not beat it. It is also just perfectly linear in driving it daily if I wanted to with torque at 1500 and power to 7000. I can say that my Eibach and Koni Sports are very sweet. I have the rear shocks set at 75% hard and the fronts at about 30% and it has just for me the right amount of oversteer now and ride quality. The rear will come around now with a letting up on entry and at the apex putting down the power it just jumps out of the corner very control with nice drift. Love it. And the ride is just tighter than stock not bone jarring as before. Hey Marcus I just don't think I can pass almost 1000.00 bucks by the boss (wife)with Mad Max's Ad Specialties under the table biz. LOL!