I have tried to get the answer to this in the performance section but haven't had any responses. 

 

I have quite a good handle on suspension setup and how different things achieve different results. I had B6 shocks fitted earlier in the year and now I would like to try lowering springs. B12 pro kits used to come with B6 shocks and the B12 sport with B8. With the B8 being shorter it is designed specifically for shorter springs.

Now ALL B12 kits come with B8 shocks.

 

Q1: as eibach pro springs are compatible with OEM shocks what is the issue with fitting them to B6 shocks being the same length as standard?

 

Q1: what specifically is the advantage of the shorter shock for lowering if there is no slack in the spring at full extension with B6/stock?

I suspect at least  part of the answer is that you're preloading the spring. So the ride comfort will not be as good as with the shorter piston of a B8. But that also would mean that turn in should be sharper as there's less squidge. There shouldn't be an "issue" per se. 

 

I run B8s on the A2. I wouldn't give them up for much else - there's Eibachs on there as well and it's glorious. The only reason I did 8s vs 6s is because of the drop and a recommendation on the A2 forum that I should be using the correct length of piston for the drop I was getting. Since it's officially -30mm, I went B8. I haven't regretted it. The damping characteristics are apparently the same on both, it's just the length. And to get the drop, the shorter piston may be necessary. I suspect that's the reason the change has happened - that too many complained about the lack of lowering and the easy way out is just to switch to the shorter dampers.

 

 - Bret 

10 hours ago, brettikivi said:

I suspect at least  part of the answer is that you're preloading the spring. So the ride comfort will not be as good as with the shorter piston of a B8. But that also would mean that turn in should be sharper as there's less squidge. There shouldn't be an "issue" per se. 

 

 

That is something that is important to me.  I suspect turn in would be sharper with B6 on Pro kit springs but the 'comfort' comes from the added droop available?  This added droop may offer body lift on the inside when cornering.  I wander how much this would compare to classic body roll with standard spring height.

 

10 hours ago, brettikivi said:

 

I run B8s on the A2. I wouldn't give them up for much else - there's Eibachs on there as well and it's glorious. The only reason I did 8s vs 6s is because of the drop and a recommendation on the A2 forum that I should be using the correct length of piston for the drop I was getting. Since it's officially -30mm, I went B8. I haven't regretted it. The damping characteristics are apparently the same on both, it's just the length. And to get the drop, the shorter piston may be necessary. I suspect that's the reason the change has happened - that too many complained about the lack of lowering and the easy way out is just to switch to the shorter dampers.

 

 

I see the recommendations all over different forums too but no real explanation as to why.  The drop is a combination of shock and spring.  I expect the B6 combo to maybe not offer the complete drop of B8 and pro springs, but I am only looking for a mild drop to reduce arch gap a touch and complement the shocks I already have (in looks, performance and comfort).

1 hour ago, MarkyG82 said:

The drop is a combination of shock and spring. 

 

No, spring controls ride height, the shock has no effect. They offer different length piston rods for two reasons, 

 

1 To pre-load the spring when the strut is unloaded to prevent the spring unseating or rotating. The car weight will compress the spring further so this pre-load will have no effect on the ride height. If it does the shock piston rod is too short.

 

2. To allow the shock to work in it's designed range of movement

 

With a mild lowering shouldn't make any difference, both will work. If in doubt go with the shorter B8

 

 

7 minutes ago, flybynite said:

 

No, spring controls ride height, the shock has no effect. The spring perches vary between manufacturers thus changing the ride height albeit by a couple mm each way.  They offer different length piston rods for two reasons, 

 

1 To pre-load the spring when the strut is unloaded (is lifting on the inside due to cornering counted as unloading?) to prevent the spring unseating or rotating. The car weight will compress the spring further so this pre-load will have no effect on the ride height. If it does the shock piston rod is too short. This makes more sense.

 

2. To allow the shock to work in it's designed range of movement. As far as I can tell the B6/B8's are not position sensitive.  They will provide the same damping characteristics across the stroke.  You are right that a lowering spring with the B6 will not use the top end of the range in the same way.

 

With a mild lowering shouldn't make any difference, both will work. If in doubt go with the shorter B8.  Issue with that is I have B6 fitted already 🤦‍♂️

 

 

I guess I am trying to understand the dynamics of how a set lengths shock will perform with different stiffness springs.  Essentially, if the pro-kit springs are pre-loaded at full extension with the B6 they are effectively a lower spring rate as standard springs, at least at the start of the stroke.  Would this offer a significantly more comfortable ride over the shorter B8 or would the increased damping of the B6 over stock cause the whole system to perform incorrectly?  Over damping a light spring is as bad as under damping a stiff spring.  But then the light portion of travel is only at the very top of the stroke helping prevent top out and also helping it from blowing through the first few inches travel following a dip for things like potholes.

 

AAAHHHHHH!!!!! my head is going round in circles!!!  I guess I'm trying to convince myself that pro-kit springs will perform better than stock on full length shocks and better than B8 in some instances.....

17 minutes ago, MarkyG82 said:

As far as I can tell the B6/B8's are not position sensitive.  They will provide the same damping characteristics across the stroke.

Not if they hit the bottom.

 

15 minutes ago, MarkyG82 said:

(is lifting on the inside due to cornering counted as unloading

Yes,  any situation that takes weight off the wheel. 

 

9 minutes ago, MarkyG82 said:

Essentially, if the pro-kit springs are pre-loaded at full extension with the B6 they are effectively a lower spring rate as standard springs, at least at the start of the stroke.

You are over-thinking this, confusing yourself and confusing me. If you have the torsion beam suspension you are never going to sort it completely

 

If you have B6 fitted then leave them on and put the Eibach springs on or you could try standard VRS springs for a bit less lowering.

 

IMHO the Octy is over damped and under sprung. it is also has a woefully undersized rear anti roll bar

6 minutes ago, flybynite said:

Not if they hit the bottom. Is this to do with the shorter bump stops?

 

Yes,  any situation that takes weight off the wheel. 

 

You are over-thinking this, confusing yourself and confusing me. If you have the torsion beam suspension you are never going to sort it completely

 

If you have B6 fitted then leave them on and put the Eibach springs on or you could try standard VRS springs for a bit less lowering.

 

IMHO the Octy is over damped and under sprung. it is also has a woefully undersized rear anti roll bar

 

Yep I have the torsion beam.  Rarb is something I may look into further down the line.  There is a nuespeed one specifically for the MQB torsion beam that looks good.

 

Prokit getting ordered later then.

3 minutes ago, MarkyG82 said:

Is this to do with the shorter bump stops?

 

They get shorter when they get worn away due to constant hitting, it then allows the piston to hit the bottom

 

agreed on the overdamped / undersprung. Rear ARB is also on the A2 and it was / is awesome. Close to zero body roll now with a minimal reduction in comfort. Well worth it.

 

 - Bret

With Eibach springs and Bilstein shocks what is the difference comparing with standard and vrs setup, is it any more comfy? Because standard suspension is actually uncomfy and bouncy. 

I would expect, considering how a standard car is sprung, that you'll get a lot less body roll in corners, but low speed bumps will still be pronounced. High speed stability should be greatly improved, with a sharper turn-in - so less thought when you turn the wheel - and an awful lot more body control around lower speed corners. A lot of difference could also be bought with lighter wheels, preferably with lower profile tyres. But that again comes with a comfort price... the squidge does have a reason. I run B8 and EIbach on the other car, with Team Dynamics wheels and 195/50R15s. H&R ARBs front and rear. Powerflex ARB bushes and dogbone mount. Meyle HD Droplinks. That thing is nuts... i don't have to brake for a 90 degree curve, just lift. And then I can apply almost a half-turn of lock for a roundabout without braking much, if at all. Great fun for me, not so much for the passengers. Gravity really pushes you sideways in that car

 

If I was to keep the 1.0 past lease, this is the thing I would do, definitely; B8 + Eibach + ARB + Mounts. Then some nice light rims - like Autec Wizards or Club Racing in 17 with 225/45R17 or 18 at 225/40R18.

 

 - Bret 

I agree that standard suspension on high speed was unstable, even worse with some side wind, but comfort is also bad even with 225/45/17. I was more interested to lower and increase comfort so I went for KW street comfort coilovers, it feels more tight with much less body roll but it is actually more comfy over bumps and speed bumps than standard setup.Springs plus shocks was other option but I didn't want to lose comfort, did I make the right choice? 

If you want comfort and a lower ride height I would opt for Koni FSD and Eibach. Had this set up on my Fabia VRS and it worked brilliantly. You have the performance when needed but a nice damped drive and it never got fidgety on bumpy roads.

Springs arrived this morning. Being fitted Tuesday, along with tracking which is way out after hitting a pothole the other week.  Looking forward to driving in a straight line more than anything.

There are sharp edged speed bumps around my house which will be the first test on the way home.  How long until they settle fully?

At least one week before doing wheel allignment. 

9 hours ago, Ecomatt said:

If you want comfort and a lower ride height I would opt for Koni FSD and Eibach

 

Koni, Bilstein, Eibach, H&R are all makes I have used to very good effect, unfortunately if you want something specific, conventional springs and dampers are always going to be hit-and-miss, you will need to go coilover.

 

As with anything but particularly with coilovers there is a lot of cheap rubbish out there and they get a bad name.

 

I have the KW V3 on an MQB car and it is very impressive. You can set the ride height exactly, and then change it if you need to. You have full control over damping and it also has a very clever compression adjustment that lets you set the slow compression (bodyroll) without affecting the fast compression (pothole). You can have a very stiff car that goes over bumps well. On its full-height and full soft starting settings it has a very good ride.

 

Not cheap but you get what you pay for.

Does the damping adjustment must be same on front and rear shocks? 

1 hour ago, FrankLK said:

Does the damping adjustment must be same on front and rear shocks? 

 

I imagine with the axle weight at the front being higher and spring stiffness being higher also that the damping with need to be increased to compensate. Manufacturer may have taken this into account though and made the valving to match the axle weight.

5 hours ago, FrankLK said:

At least one week before doing wheel allignment. 

 

Can you elaborate? I am in desparate need of alignment but was planning on having the springs done at the same time. Shirley the settling won't affect the geometry that much?

1 hour ago, MarkyG82 said:

 

Can you elaborate? I am in desparate need of alignment but was planning on having the springs done at the same time. Shirley the settling won't affect the geometry that much?

Lowering itself will offset allignment and further settling of springs also, why not wait to final settle and then do final allignment?

Is it possible that petrol dsg cars have more weight on gbx side? 

 

2 hours ago, MarkyG82 said:

 

Can you elaborate? I am in desparate need of alignment but was planning on having the springs done at the same time. Shirley the settling won't affect the geometry that much?

 

 

37 minutes ago, FrankLK said:

Lowering itself will offset allignment and further settling of springs also, why not wait to final settle and then do final allignment?

Is it possible that petrol dsg cars have more weight on gbx side? 

 

It depends on how good the people are that fit the springs. If you seat everything carefully as you are building back up and putting things back under tension, there is very little settling.

 

A good person doing the alignment will bias the settings to one side of the allowable tolerance to have the setting move toward the centre if there is any settling movement.

 

That said I don't rate your chances of finding too many people that can do any of the above so I would drive it for a bit and then get it tracked.

 

2 hours ago, MarkyG82 said:

 

I imagine with the axle weight at the front being higher and spring stiffness being higher also that the damping with need to be increased to compensate. Manufacturer may have taken this into account though and made the valving to match the axle weight.

Front axle 950kg

Rear axle 930kg

KW recomendation is:

Rear more damping than front, for now I set both same on middle setting which is default so I can go only in the way of more damping of front if I want more ride comfort. 

Some figures there that are a lot closer to balanced than I expected. I have a tdi dsg so possibly more balanced to the front?

 

The guys doing the work build highly tuned cars bordering on race cars so absolutely know their stuff. Whether they will go as far as presetting the tracking to settle towards center? I dunno. I could ask as I get on quite well with them. Good shout though.

Had pro-kit springs fitted yesterday. 

First impression:

 

Body roll greatly reduced

Small bump control is improved

Medium bump at mid speed is much better.  Went over a sunken manhole cover and the car barely moved

All bumps at low speed improved

The only area where it feels like its transferring more into the body is unstable road surfaces like country roads.  The car is a little more active but not jarring

Speed bumps of various sizes (I see them daily) are now much less crashy.

 

Not had a chance to take it over 60mph yet or on motorway.  Will add to this once I have.  Floor to wheel arch was 26 1/2 inches front and 27 rear before fitting.  Will check the height at some point today to see the difference then maybe again in a few weeks to see if they have settled.

On 13/12/2019 at 21:39, FrankLK said:

I agree that standard suspension on high speed was unstable, even worse with some side wind, but comfort is also bad even with 225/45/17. I was more interested to lower and increase comfort so I went for KW street comfort coilovers, it feels more tight with much less body roll but it is actually more comfy over bumps and speed bumps than standard setup.Springs plus shocks was other option but I didn't want to lose comfort, did I make the right choice? 

What car was this on?