Suspension help needed

[Johnboy1974]

Hi guys thank you forcaccepting me on the forum.
I need some advice regarding the suspension on my car...its an open corsa vxr 2011 model.
Recently I upgraded the suspension all round on the car by fitting bilstein b8 struts along with eibach prokit coil springs. This lowered the height of the car by around 15mm.
The car drives great on motorways and smooth roads but on uneven roads I feel its bouncing a bit and I feel like a nodding dog. I've never driven on this kind of set up before so I'm not sure if this is normal or not.
Any input is appreciated.

[Pica-Pica]

The dampers are wrong, I would say. Springs only control the height v load. Was the set up done all in one go by a specialist, or was it more ‘pick-and-mix’.

[Johnboy1974]

Thank you for reply...This set up is well used in the corsa vxr world and known as a good combination. I done the job myself.
I've asked the question on the vxr platforms but no one seems able to give me an answer.

[oakdale]

I'd expect it to feel like you describe, improved road holding but poorer ride.

[Johnboy1974]

oakdale said:

I'd expect it to feel like you describe, improved road holding but poorer ride.

Any tips to help it stop bouncing on uneven roads...seriously thinking of going back to stock after spending serious cash.

[Pica-Pica]

oakdale said:

I'd expect it to feel like you describe, improved road holding but poorer ride.

But the poorer ride would normally be a harsher ride, that is the damping is too much. In this case it seems that long suspension travel is inadequately damped.

[Dynion Araf Uchaf]

are your dampers adjustable.

If your car is bouncing or floating a bit then it doesn't have enough rebound or may have too much bound, so stiffen the damper up a few notches or soften them off.

[E-bmw]

It could be a good idea to get the car in the air & check everything is attached/fitted properly.

Personally I wouldn't normally recommend mixing manufacturers parts for shocks/springs as they may not necessarily be compatible, not being developed to be fitted together.

[AW111]

E-bmw said:

It could be a good idea to get the car in the air & check everything is attached/fitted properly.

Personally I wouldn't normally recommend mixing manufacturers parts for shocks/springs as they may not necessarily be compatible, not being developed to be fitted together.

Given that some of the best shocks in the world are made by companies that don't make springs (like Bilstein and Koni) are you saying they shouldn't be used?

[Johnboy1974]

E-bmw said:

It could be a good idea to get the car in the air & check everything is attached/fitted properly.

Personally I wouldn't normally recommend mixing manufacturers parts for shocks/springs as they may not necessarily be compatible, not being developed to be fitted together.

Bilstein who manufacture the struts actually specify the eibach springs I have fitted....or stick with the oem springs.
I still have my oem springs in the garage will try swapping them out and feel the effect it has.

[Johnboy1974]

Dynion Araf Uchaf said:

are your dampers adjustable.

If your car is bouncing or floating a bit then it doesn't have enough rebound or may have too much bound, so stiffen the damper up a few notches or soften them off.

No unfortunately the dampers are not adjustable.

[Johnboy1974]

OK a quick update.
This morning I removed the two rear eibach coil springs and compared them side by side with the oem springs.
The eibachs are actually longer than the oem springs but crucially the eibachs are much much softer. I could compress them down very easily but could barely compress the oem springs.
I decided to refit the oem rear springs again but keep the bilstein b8 shock absorbers.
The car used to sit with the rear slightly lower than the front but now it is completely level and after taking it for a drive it feels much much better.

Don't understand any of this but the car is sitting better and driving better so I will stick with it for a few weeks to see what happens.

[AW111]

That's a sensible approach. The Bilstiens should give better wheel control than the standard dampers, so see how you like it as it is now.

[GreenV8S]

Changing the springs for ones with different rate and/or length can make a big impact on ride and handling as well as suspension geometry.

In particular if the changes are different front/rear it can cause substantial ride and handling problems.

Aftermarket springs being sold as an upgrade are typically a little stiffer than standard and it is not at all common in my experience to offer springs for a vehicle which are softer than OEM, especially by as much as you're describing. I'd wonder whether you were sent the wrong springs or mixed up the front and rear springs.

It sounds as if you have improved things by putting the rear springs back to standard, but if you replaced the fronts too they might also be wrong even if the symptoms are less intrusive.

[Johnboy1974]

No chance of getting front and rear springs mixed up...the rears are way shorter on the corsa...the fronts simply would not fit.
Will see what pans out in the next few weeks. Possibly might need to bite bullet and buy genuine vauxhall if symptoms persist.

[gareth h]

What size wheels are you using, I have often dropped the diameter by an inch (and increased tyre profile), it will improve ride and you keep decent body control.

[Johnboy1974]

Tyre size is 225/35/r18
Tyres are new and expensive...I might take them up to 225/40/r18 at next replacement.

[LunarOne]

AW111 said:

E-bmw said:

It could be a good idea to get the car in the air & check everything is attached/fitted properly.

Personally I wouldn't normally recommend mixing manufacturers parts for shocks/springs as they may not necessarily be compatible, not being developed to be fitted together.

Given that some of the best shocks in the world are made by companies that don't make springs (like Bilstein and Koni) are you saying they shouldn't be used?

Yes it makes no sense. Eibach make springs and they partner with Bilstein for the shocks that they sell as a kit.

[E-bmw]

LunarOne said:

AW111 said:

E-bmw said:

It could be a good idea to get the car in the air & check everything is attached/fitted properly.

Personally I wouldn't normally recommend mixing manufacturers parts for shocks/springs as they may not necessarily be compatible, not being developed to be fitted together.

Given that some of the best shocks in the world are made by companies that don't make springs (like Bilstein and Koni) are you saying they shouldn't be used?

Yes it makes no sense. Eibach make springs and they partner with Bilstein for the shocks that they sell as a kit.

I won't argue with you, I was talking generically as I said above, if these were designed to be used together and they are regularly used as such the OP needs to send them back for me as they are obviously not right assuming they were fitted correctly.

[gareth h]

Johnboy1974 said:

Tyre size is 225/35/r18
Tyres are new and expensive...I might take them up to 225/40/r18 at next replacement.

Try picking up a 2nd hand set of 17” rims and tyres, it will probably resolve the problem