1.4TSI estate with torsion beam rear.

 

Will a pair of Bilstein B4 or similar make a significant improvement to the ride? Would it require something with more complex, cartridge damping?

 

The OEM suspension appears to be setup to absorb big bumps, but not smaller, high frequency bumps.

 

I've experienced similar with motorbikes and changing the rear damping could improve the whole bike.

They do seem to wallow a bit and get unsettled quite easily over smaller undulating surfaces.

 

When the suspension was worn out on my mk2 I replaced it with a b12 kit and the problem stopped instantly.

 

As such, I’d agree with your logic, although I would consider doing all 4

I'm changing all 4 on mine for b6 shocks on Tuesday. I agree that the rear is an issue on the torsion beam setup. The b4 is valved to match OEM setup so they might not improve it as much as you want. That's why I went b6.

Change the crap springs and dampers.

Springs are ok, dampers less so in my opinion.

If your car sits at the right height and has enough travel then the performance of the suspension will be 90% on the damping.

Tweaking dampers and springs can make a bit of difference, but it will always be a compromise & doesn’t change the fundamental problem of bumps being transmitted across the car by a single beam.

 

You’d almost be better sinking money into better sound deadening because the way the beam amplifies noise and vibration means the ride sometimes sounds worse than it really is.

Really springs sitting at the right height especially the cheap crap that VW Group source does not mean that better springs at the same height can not improve the ride and handling.

But if anyone knows better and is of different opinions then fair enough.

I had a friend who did just b4 to standard springs and it made most of the difference compared to the b12 on the mk2

 

Bonus was much less money and no insurance loading.

 

I personally think the cars are slightly oversprung and very poorly damped. If you look at the Passat I think there was a service bulletin to replace the dampers with a blistering variant at the rear due to issues. 

 

That as as far as I know wasn’t replicated on the suburb, which has the original part number.

 

now I could be wrong, and the beam doesn’t help, but unless you want to pay for the insurance, I would try the b4 and new bushes and see how it goes.

 

YMMV and everyone will have their own version of acceptable or not.

54 minutes ago, Skoffski said:

Really springs sitting at the right height especially the cheap crap that VW Group source does not mean that better springs at the same height can not improve the ride and handling.

But if anyone knows better and is of different opinions then fair enough.

 

You are of course right. However changing the dampers should have a greater effect on the control of the system over changing the springs. It depends what you want too. If the OEM shocks are over damped then adding stiffer springs can help. If underdamped (pretty sure mine is) then a lighter spring will only result in lower ride height. If the springs are supporting the load correctly then the logical change would be different shocks.

 

Edit: to respond to the spring comment directly. The springs that vag use may well be sub par compared to others so that could be part of the issue. That's my next step after b6's if I'm still not happy. Does anyone know if standard height performance springs are available?

Edited 30 March, 20197 yr by MarkyG82

3 hours ago, MarkyG82 said:

 

 

Does anyone know if standard height performance springs are available?

Heavy duty springs are standard height and stiffer than standard springs, that's what I have fitted to my Fabia Mk3 combi. 

As others have said, the springs are just there to set the ride height and to resist the wheels moving up over bumps and around turns. There's nothing particularly fancy about a constant rate spring. Some springs can be progressive, giving increased stiffness through the travel. Adjusting spring preload can change static ride height, but few cars have this facility.

 

Damping resists the velocity of wheel travel up and down (compression and rebound), through different circuits. Some shocks have low speed and high speed compression circuits to allow different responses to different disturbances.

 

The suspension linkage can also be linear, progressive or very non-linear through the travel.

 

The simple torsion beam suspension would probably benefit massively from some fully adjustable shocks shocks, to work around the limitations of the system. Expensive though.

 

It sounds as if the IRS is also quite harsh, though.

 

 

By comparison, I've just been driving my wife's 60k miles 56 reg Mk6 Fiesta Zetec (the previous owner had new front springs and possibly dampers fitted) The suspension on that car is a similar setup McP struts and torsion beam rear. 

 

Although the car is fairly basic and smaller than the Octavia, the ride is quite firm, but not harsh (The handling is also excellent). It is noticeably more compliant over bumps and rough tarmac.

 

 

Picked up the car yesterday after having B6 dampers fitted all round.  Initial reaction is very firm but alreay on the drive to work this morning they feel better.  Been advised that a couple of hundred miles will se them pretty much where they should be.  Also that the life of them should easily be >100k.  The old ones must have been really shot.  There is no oscillation when going over big speed bumps.  One particular improvement is weight tranfer between bend.  It used to dig in the front end and you had to be careful not to let the body roll snap back.  The same bend this morning just powered through smooth as you like.

 

In response to the original question: The rear end feels much more controlled.  Maybe too firm compared to oem fronts.  Will report back once a couple hundred miles are done.

21 minutes ago, MarkyG82 said:

Picked up the car yesterday after having B6 dampers fitted all round.  Initial reaction is very firm but alreay on the drive to work this morning they feel better.  Been advised that a couple of hundred miles will se them pretty much where they should be.  Also that the life of them should easily be >100k.  The old ones must have been really shot.  There is no oscillation when going over big speed bumps.  One particular improvement is weight tranfer between bend.  It used to dig in the front end and you had to be careful not to let the body roll snap back.  The same bend this morning just powered through smooth as you like.

 

In response to the original question: The rear end feels much more controlled.  Maybe too firm compared to oem fronts.  Will report back once a couple hundred miles are done.

Thanks for the feedback. 

How many miles does your car have?

 

It is the Initial harshness in the first part of the travel, rather than he firmness, that I notice, even in comparison with an old, basic Zetec Fiesta with a similar suspension arrangement -which is still a great car to drive.

 

I've noticed that the rear rebound damping is also a little lacking in my estate.

 

Tyres might also be a factor. My car arrive with almost new Nexen Blue plus (?) on the front and Conti Ecocontact on the back. 

 

I like Uniroyal Rainsport3 and have them on the Fiesta and the old Mondeo. Good grip and good ride.

If the old dampers were shot at 100,000 miles then likely the springs are as well.

Car has done 55k miles and had the guys check the sorings over.  I know that doesn't necessarily mean the springs are good but it they said the powdercoat is still fine.  I'll maybe look at eibach pro springs next year or so depending on how the b6's go.  Tyres on there are conti premium contact or something.  They came on the wheels when I got them last year.  Not a fan and looking forward to replacing them probably with F1 assy3/5.  How do the uniroyal's compare?

14 hours ago, MarkyG82 said:

Picked up the car yesterday after having B6 dampers fitted all round.  Initial reaction is very firm but alreay on the drive to work this morning they feel better.  Been advised that a couple of hundred miles will se them pretty much where they should be.  Also that the life of them should easily be >100k.  The old ones must have been really shot.  There is no oscillation when going over big speed bumps.  One particular improvement is weight tranfer between bend.  It used to dig in the front end and you had to be careful not to let the body roll snap back.  The same bend this morning just powered through smooth as you like.

 

In response to the original question: The rear end feels much more controlled.  Maybe too firm compared to oem fronts.  Will report back once a couple hundred miles are done.

 

The b8 was always firm, but with the pro-kit it was a more progressive firm.

They do soften up a little bit after a few hundred/thousand miles, but you won't find a massive softening of the ride.

 

13 hours ago, Skoffski said:

If the old dampers were shot at 100,000 miles then likely the springs are as well.

 

TBH if i was at 100k plus and doing one, then I would do both and I probably would go eibach prokit.

 

12 hours ago, MarkyG82 said:

Car has done 55k miles and had the guys check the sorings over.  I know that doesn't necessarily mean the springs are good but it they said the powdercoat is still fine.  I'll maybe look at eibach pro springs next year or so depending on how the b6's go.  Tyres on there are conti premium contact or something.  They came on the wheels when I got them last year.  Not a fan and looking forward to replacing them probably with F1 assy3/5.  How do the uniroyal's compare?

 

At 55k they'll probably be fine, although at they are linear you will notice they are similarly hard all through.

The prokit are a bit softer to start with and firmer towards the end and they do make for a very comfortable ride.

 

As I said before however, the lowering springs (Prokit are) and both the b6 or the b8 shocks are modifications by most insurance companies, so you will need to notify.

The B4 with standard springs are OEM replacements.

 

The b4 is very cheap, to the point that doing the b4 would probably be similar to a years worth of insurance loading, so worth a pop if you have a garage with decent labour rates.

 

Also the obvious you have checked the tyre pressures, and that the tyres have the correct loading (eg not XL tyres), as this can make a car super harsh if the tyres are very rigid.

What wheels/tyre size do you have on the car?

12 hours ago, MarkyG82 said:

Car has done 55k miles and had the guys check the sorings over.  I know that doesn't necessarily mean the springs are good but it they said the powdercoat is still fine.  I'll maybe look at eibach pro springs next year or so depending on how the b6's go.  Tyres on there are conti premium contact or something.  They came on the wheels when I got them last year.  Not a fan and looking forward to replacing them probably with F1 assy3/5.  How do the uniroyal's compare?

I've never used F1's. I've noticed that a few on here use them, though.

 

The Rainsport give great grip in the wet, dry and cold on the road. Some say they are soft in the sidewall, but the XL seemed fine on my mk4 Mondeo estate. I'd always prefer compliance, grip and progressive slip on bumpy roads to the absolute maximum of steering sharpness.

 

The Rainsport do wear fairly quickly, naturally, but they are fairly cheap.

 

Edited 3 April, 20197 yr by MC Bodge

They are 18s (225/40r18) from a vrs at the moment. Up until last week they were the original 17s (225/45r17) with winter tyres. Both sets of wheels seem to ride very similar possibly due to the extra weight and drag of the winter tyres.  I have already noticed the difference in tyre pressure required and set the 18s a few psi below what they were before. Whenever I ask in tyre shops they always offer the XL loading versions. Probably because it's an estate. You're suggesting we don't use XL?

 

I'll put the rainsports on the list.

Driving and observing this morning, although there is a thud from the front over small bumps, the rear gives a bigger one.

 

As I'd observed in the past, bigger bumps such as speed humps are dealt with reasonably well.

 

It is the small bump sensitivity that is the problem. On more sophisticated, air suspension systems this can be improved with negative spring air pressure.

On 03/04/2019 at 15:03, MarkyG82 said:

Picked up the car yesterday after having B6 dampers fitted all round.  Initial reaction is very firm but alreay on the drive to work this morning they feel better.  Been advised that a couple of hundred miles will se them pretty much where they should be.  Also that the life of them should easily be >100k.  The old ones must have been really shot.  There is no oscillation when going over big speed bumps.  One particular improvement is weight tranfer between bend.  It used to dig in the front end and you had to be careful not to let the body roll snap back.  The same bend this morning just powered through smooth as you like.

 

In response to the original question: The rear end feels much more controlled.  Maybe too firm compared to oem fronts.  Will report back once a couple hundred miles are done.

Nothing like having full control over your rear end

I am suggesting to use the weight loading your car was specified with.

 

if it’s 92 then 92, if 94XL then so be it.

 

The stiffer the sidewall, the less give you have to deal with poor surfaces.

1 hour ago, cheezemonkhai said:

I am suggesting to use the weight loading your car was specified with.

 

if it’s 92 then 92, if 94XL then so be it.

 

The stiffer the sidewall, the less give you have to deal with poor surfaces.

Some tyres are stiffer than others.

 

Rainsport3 are considered soft in the sidewall. I've never had complaints about them.