VA-Poltern beim Ibiza 6L / zu hartes Cupra-Fahrwerk | Posts 16+

Hi,
Our Ibi also has sports equipment (steering wheel, seats, suspension). For me, the driving behavior, which is very stiff, especially at the rear because there's no weight there, is okay. My mother, who owns the car, says that it bounces too much for her.

@Ulf, I would only install a complete suspension system, because the springs and dampers need to be matched in their characteristics. A coilover suspension is advantageous because of the precise height adjustment it allows.

I have had very good experiences with Koni yellow shocks and Eibach springs (durability, corrosion resistance).

I once owned a brand new 1.8T Cupra Leon. After about 35,000 kilometers, I lowered it by having the springs compressed and installing OEM (Original Equipment Manufacturer) shocks.
Result: Excessive bouncing and swaying on the track due to insufficient pre-tension of the springs.

RedR32 wrote:

@Ulf I would only install a complete suspension system, because the springs and dampers must be matched in their characteristics.

I understand what you mean.
However, a factory-installed spring-damper combination for a practically identical car (96kW TDI with practically the same rear axle load), using the same springs but with different (softer) dampers, should also produce usable results, just like with the 96kW model equipped with a sport suspension (instead of a Cupra suspension), according to my theory.


Regarding the tie rods:
(If I recall correctly, from the Peugeot 205) the ball joints in the plastic housings are quite tightly mounted.
If a component experiences "Klapper" (loosening), does that manifest as a looser/more wobbly bearing feel? Then I could briefly unscrew those parts and test them by feel, instead of replacing them based on suspicion .

The only solution is to take a test drive in a 96kW TDI Ibiza.
If you can get a suspension system at a good price, that would be a viable option.
The Cupra also uses different wheel bearings (as mentioned above), and I'm not exactly sure where they are located, but I'll ask around and see what I can find out.

I think the OEM suspension is a compromise between comfort and sportiness, but it's geared more towards sportiness in the Cupra. Well, the performance of the car speaks for itself.
How that works with the 195 tires with steel rims is a mystery to me.

Kauf dir ein Fahrwerk mit einstellbarer Zug-u.Druckstufe, die sind bei niedrigster Einstellung weicher als die orig. Shock absorber.

The tie rods rattle when they are worn out.
If the "pothole track" is too rough, an impact buffer on the damper might also cause noise.
Jack up the car on one side and manually push down on the suspension, feeling for any play between the spring and the body, before fully jacking it up.

RedR32 wrote:

Well, the performance of the racing bread speaks for itself. How that works with the 195 tires with steel rims is a mystery to me.

This is my tuned Polo, and it also drives .
For the 6L Cupra, the (minimum) tire width is at least 205 .

Quote:

Buy yourself a suspension system with adjustable rebound and compression damping; even at their lowest setting, they are softer than the original shocks.

I'm not a suspension fanatic, and therefore I don't want to spend endless hours tweaking it.}
Therefore, I'm leaning towards a simple OEM spring and damper combination, as mentioned above.

Oops, sorry.
205s, of course. They're too small for me given the power output. I want to be able to make progress.
I'm just saying, the original suspension offers a decent compromise between sportiness and comfort.
I would just leave it as it is. The 96kW sports suspension probably isn't much different due to the high front axle load.
Especially, where can you find all the parts in good condition at a reasonable price?
Do you want to lose your operating license?
You probably want to experience high speed on the train sometimes, and softer suspension isn't ideal for that.

The problem lies in the unfavorable weight distribution between the front and rear.

"Go ahead and fill the tank completely, put something heavy and flat in the back, and then take it for a drive. Experience is the best teacher."

RedR32 wrote:

205, of course. It's too small for me given the power. I want to make progress.

"205s are enough; I have them on mine too."

RedR32 wrote:

The 96kw sports suspension is probably not much different due to the high front axle load.

A little softer would already be enough for me. And if the dampers have different part numbers (with the same springs), they probably won't be harder than the ones on the Cupra, but rather softer.

Quote:

Especially, where can one obtain all the parts in good condition at a reasonable price?

The price range of 50€ per damper for new OEM parts (instead of questionable used ones) is still acceptable. The springs will be reused anyway.

Quote:

Do you want to lose your operating license?

Interesting topic, new to me. Everyone is tinkering with and modifying their suspensions, but I haven't read much about the operating license issue. I've mostly read about the suitability of the tires to get the TÜV approval. Dampers have never been an issue.
Do all shock absorbers from accessory shops have a specific approval certificate (ABE) for the vehicle types they are intended for?

Quote:

You probably want to experience high speed on the train as well, but softer dampers aren't ideal for that.

In a 160 HP TDI, whose maximum speed in the "longest" gear is theoretically 186 km/h? High speed means something different to me: every 96kW TDI of the Polo 9N platform with the long gearbox (240 km/h @ 4000 rpm in 6th gear) is faster, even with a slight tailwind or downhill slope.
The Cupra is designed as a fun, acceleration-focused car. It also needs the short gear ratio to avoid being bogged down by its 1.25-ton unladen weight (without driver!).

Quote:

The problem lies in the unfavorable weight distribution between the front and rear. Try filling the tank, putting something flat and heavy in the back , and then driving it. Experience is the best teacher.

And what should I pay attention to in order to draw conclusions that point towards softer shocks in the front ?

ulf wrote:

Do all shock absorbers from the accessory market have an explicit ABE (General Operating Permit) for the vehicle types they are intended for?

No. Shock absorbers do not need to be registered, only springs. With coilover suspension systems, only the thread length or other dimensions of the shock absorber need to be specified in the documentation. The ABE (General Operating Approval) for the springs will state what information needs to be included.

At around 60€ per shock absorber, you can certainly try them out, but finding the right one to buy won't be easy.

Here's a brief overview from Seat:
(Below is some information about suspension systems.)
http://www.autobild.de/artikel/fahrbericht-seat-altea-fr_54056.html

Okay, I tried replacing the stabilizer bar bushings today, but it didn't work -> it's still making the same clunking noise as before.
While I was working on the car, I also removed the stabilizer links (connecting the shock absorber to the stabilizer), but I couldn't find any replacements, so I reinstalled the old ones.
"When I manually shake the tie rods, there's no rattling. However, the very slight play between the rods and all the threaded parts makes me a bit suspicious. Because on brand new rods, the ball joints used to be very tight in their bearings. Although, that knowledge is about 15 years old and refers to my old Peugeot 205 GTI, where I managed to eliminate the clunking noise by replacing the tie rods."

Question: Are the ball joints of new and rattle-free VAG tie rod ends so easily movable that the threads automatically position the rubber caps in their resting position, or does such ease of movement still today often indicate (the beginning of) VA (rear axle) noise?

Hi Ulf:
None of the accessory tie rods I installed moved easily in the ball joint.
Secure the workpiece in a vise and apply strong pulling/pushing force.
If there's no air flowing through it, it won't rattle when it's installed.

teileklaus wrote:

All of the accessory tie rods that I installed were not easy to move in the ball joint.

This supports my suspicion.

Quote:

Clamp the part in the vise, pull/push firmly. If there is no air

, it will not rattle when installed. I also tried it yesterday, but without any clear evidence of rattling. }
Either my ~60 kg of weight in motion isn't enough to make these rods rattle (during the preliminary test by hand, all heads felt equally easy to move, but nowhere was there any play -> perhaps they have just started to rattle, and the loudest joint isn't yet noticeably loose), or I didn't check the rattling joint in the vise, because I didn't systematically check each one individually }.

Update: Today, an experienced technician inspected the installed rods on the stage (by moving them strongly up and down), and by feeling the rods, I could clearly feel the play/looseness.
Therefore, these things are quite worn, with mileage that is suspiciously high, at a record-breaking 25,000 km .

*warm-up*

The rattling problem is gone, but the Cupra suspension is still too stiff for my taste.

If I install the front dampers from the sport suspension, I should (hopefully approximately) achieve the same front-end comfort as the ASZ Polo, because it has the same springs as the Cupra, and I already find it significantly better than the Cupra on rough roads.
On the other hand, the Polo has 195/55R15 tires, and the Cupra has 205/45R16 tires... therefore, the Cupra probably won't be as comfortable as the Polo .

Looking at the rear, things get a bit more complicated, because the Cupra has different springs AND different dampers than the Polo.
Let's say the springs and dampers are stiffer than those in the Polo, and I'm installing the same dampers that are used in the Polo:
Does this (with the same load) result in a stronger/longer tendency to oscillate after stopping compared to the Polo, or does the overall damping remain higher than in the Polo due to the stiffer springs?

I'm trying to imagine this as an analogy to an electrical oscillating circuit, because I'm somewhat familiar with those.

Feather = compressible = capacitor.
Mass = moving element = coil.
Damper = dissipates kinetic energy = series resistance to the coil.

A stiffer spring would correspond to a smaller inductance (because both increase the natural oscillation frequency) and would increase the damping. If this analogy holds, the Cupra, with its OEM springs and the rear dampers from the Polo, should remain stiffer than the Polo .

Experiences from my rally driving days: The rear axle should be stiff, but not rock-hard. Excessive body roll on the rear axle can, in extreme cases, trigger weight transfer reactions – usually when you least expect them. Potentially dangerous! A rear axle that is too stiffly sprung reduces possible cornering speeds, but is generally easier for most drivers to handle, as the initial loss of grip in corners is often signaled early on through audible cues and through the feeling in the seat. In vehicles equipped with ESP, the tolerated cornering speed is even further reduced, as the systems (brakes, engine control, and possibly an automated transmission) constantly adjust each other.

If you want something that offers both comfortable and dynamic handling, you'll want to allow for as much suspension travel as possible with a "softer" spring, while simultaneously trying to control vehicle movements with a stiffer damper setting. For overall comfort, a progressive spring rate can be beneficial, allowing for suspension comfort during normal driving, but becoming stiffer as the suspension travel is increasingly utilized, for example, in the last third of the travel. If you want to go all out, adjustable dampers with separate compression and rebound settings are worth considering, but their adjustment is time-consuming and requires several test drives on familiar roads.

Always consider the parameters of the stabilizer bars and their bushings. The bushings can be replaced if necessary, for example, with plastic instead of rubber. A thicker stabilizer bar than the standard part may be available and could be installed. This usually has the most significant effect, even with standard springs and dampers. That's why, in my suspension modifications, I always started there if suitable parts were available.

"For my 206, the solution was to use the torsion bars (spring elements) and rear shock absorbers from the SW (estate/wagon) model, which I also purchased from Koni. The front axle already had the factory-installed lowering kit with 0.5 mm thicker springs, and I've since added stiffer shock absorber cartridges from the GTI or RC models. This, in turn, requires replacing the strut mounts. In addition to the already installed thicker anti-roll bar, I also added stiffer bushings."

If the car with its 68 horsepower now also offered the corresponding performance... Well, I don't necessarily have to take my foot off the accelerator when turning right in town. And the tires don't squeal either. It's also good for drivers who, in tighter corners where you can often take away several times their vehicle length because they can't get through the curve nearly as fast, are still driving straight ahead. It's a good thing I don't have ESP!

Since I also own a 9N with a 2.0 TDI BKD engine and a Golf V GRF gearbox, which makes the front of the car very heavy, I also have the solid rubber bushings, similar to those found in the A2 model.

Just one more tip for Ulf: When you replace the control arm bushings or the entire control arm, make sure to tighten the screw that comes in from the front to the specified torque (while the suspension is in its normal, unloaded position)!

There are also polyurethane bushings with a high Shore hardness available for the front mounting point. For the Polo / Ibiza, they cost 50€ for a set (2 pieces) . The same applies to the stabilizer bar bushings, but they are not 50€...

Since mine is also making a ticking sound, I'm going to try these things out, along with some new control arms.