18 minutes ago, hhcd80 said:

Thanks for your help @Carlston. Going  by the part numbers given, B4s are basically closest to OEM. I might go for B6s though if my budget can stretch to them. Are B6s that much harder computer to B4s?

 

Bilstein B6 and Bilstein B8 are a mono-tube design, whereas Bilstein B4 are a twin-tube design...at least with most VAG cars. I did see some half price B6 for a Dacia, but they were the cheaper twin-tube design rather than the more expensive mono-tube design.

 

Mono-tube is superior to twin-tube.

 

B6 and B8 aren't necessarily harder than B4. It would cost Bilstein nothing to make the B4 harder by using different valving at the manufacturing stage, if that increased the performance.

 

It's better to think of B6 and B8 as simply higher quality than B4, rather than harder. However, once you go past B4 I expect diminishing returns comes quickly.

 

With the VRS, B6 and B8 are probably a good idea.

 

Edited 12 September, 20232 yr by Carlston

Genuine Skoda buffer for rear shock absorber 122mm (matches 5Q0511357G)

https://www.skoda-parts.com/spare-part/5q0511357g-shock-absorber-stop-buffer-skoda-26793.html

 

Genuine Skoda dust cover for rear shock absorber (sold to replace 5Q0513425D and 5Q0513425J)

https://www.skoda-parts.com/spare-part/5q0513425j-rear-shock-absorber-sleeve-skoda-21700.html

 

Edited 12 September, 20232 yr by Carlston

13 hours ago, hhcd80 said:

Thanks for your help @Carlston. Going  by the part numbers given, B4s are basically closest to OEM. I might go for B6s though if my budget can stretch to them. Are B6s that much harder computer to B4s?

 

As @Carlston says.  The B6/8 is a monotube design.  This design allows for the valves to be bigger diameter which offers greater performance.  The oil volume is also greater which offers a larger potential heat capacity.  The way Bilstein design them is with high pressure gas above the sealed oil volume.  It help prevent cavitation in the oil.  This is partly what people describe when talking about them being harder.  It's a combination of high pressure and slower damping.  I can reccomend them as a straight swap with stock height or with lowering springs.  They are a great improvement over the standard suspension.

@MarkyG82@MarkyG82 Thanks for that. Wasn't sure if B6 cause the ride to become rock hard. Not against that as I would prefer that to soft wallowing suspension

Just now, hhcd80 said:

@MarkyG82@MarkyG82 Thanks for that. Wasn't sure if B6 cause the ride to become rock hard. Not against that as I would prefer that to soft wallowing suspension

 

Definitely not wallowing. Also not rock hard. Controlled and supportive is the best way to describe it. Add in aftermarket lowering springs and it becomes quite hard but I never had complaints from MrsG or the kids with the old car. New one has the same springs but on koni shocks and I'm not a fan. Will swap to B6 when appropriate.

I've had B4s on many cars and always been happy with them. Most of these cars have been sportier models with slightly firmer suspension however. 

 

The VRS is no difference, with very slight lowering springs (20mm all round) and B4s I would say 10% increase in stiffness. It's barely noticeable over stock however this is comparing it to leaking shocks with almost 90k on so maybe not the best comparison.

 

I believe it was Carlston who informed me that the same part number for the B4s is also used for non VRS models including those with smaller engines. I haven't felt that they are overly soft or bottom out easily so I can only presume the weight difference is negliable. They have had a good shake down of two days of driving country roads around Wales and Warwickshire in August and I was impressed with them.

 

I have never compared the B4 and B6 to see the difference however I would expect a slightly more controlled ride. I'd guess this will be marginal. The way I would see a B4 is OE equivalent, the B6 a slight upgrade.

Thanks for the input all. 

It is looking like ultimately it is down to budget. I been looking at the prices between B4 and B6 and "Oof". 

The car's MOT is soon. We'll see if the suspension needs work at that point. 

Don't forget fitting costs are the same (unless fitting yourself).

18 minutes ago, MarkyG82 said:

Don't forget fitting costs are the same (unless fitting yourself).

And the fact that if the shock is toast, everything else around it will be.

 

Not sure if I mentioned it on here or my project thread but EVERYTHING was seized, rusty and didn't want to move. We had to cut off my track rod ends and ARB links. I suspect as a result of everything being new my offside inner track rod has decided to give up and is hopefully being replaced. If I can, I'll change the nearside too so I don't have to worry about tracking twice in a potentially short space of time. Likewise the bottom ball joints are worth considering to replace as well.

You have inner track rods that are not only conscious of their surroundings but can also make decisions like giving up when surrounded by new parts? 😯

 

I have heard of inbuilt obsolescence but that is taking it to a new level!

Sorry me again.
@CarlstonIt has been suggested I might need to get some fresh springs as well. Could you find the right part number for both front and rear springs? I'll get you further details if you need them.

58 minutes ago, hhcd80 said:

Sorry me again.
@CarlstonIt has been suggested I might need to get some fresh springs as well. Could you find the right part number for both front and rear springs? I'll get you further details if you need them.

 

The OEM part numbers for the springs depends on the car's build codes as shown below.

 

Octavia MK3 2.0TDI VRS hatchback 2WD

Front springs for manual gearbox 5Q0411105HC or 5Q0411105HD

Front springs for automatic gearbox 5Q0411105HD or 5Q0411105HE or 5Q0411105HF

Rear springs 5Q0511115P or 5Q0511115Q

 

Front springs

1	5Q0411105HC	Coil spring 1 paint mark 1 paint mark	green Grey	2	PR-L16
1	5Q0411105HD	Coil spring 1 paint mark 1 paint mark	brown white	2	PR-L17
1	5Q0411105HE	Coil spring 1 paint mark 1 paint mark	brown yellow	2	PR-L18
1	5Q0411105HF	Coil spring 1 paint mark 1 paint mark	brown orange	2	PR-L19

Rear springs

1	5Q0511115P	Coil spring		2	PR-1JE+0YC
1	5Q0511115Q	Coil spring		2	PR-1JE+0YD

 

Edited 27 September, 20232 yr by Carlston

What build codes do you need from me to confirm for sure?
EDIT: Never mind, I think I found them. "L16 - Suspension range 16 installation control only, no requirement forecast" so I guess "5Q0411105HC "?

Edited 27 September, 20232 yr by hhcd80
NVM found them

16 hours ago, hhcd80 said:

What build codes do you need from me to confirm for sure?
EDIT: Never mind, I think I found them. "L16 - Suspension range 16 installation control only, no requirement forecast" so I guess "5Q0411105HC "?

 

So you have build code L16 which means the front springs have OEM part number 5Q0411105HC, and build codes 1JE+0YC which means you have rear springs with OEM part number 5Q0511115P.

 

I've listed 5Q0511115Q below as well as 5Q0511115P, because this could be a cheaper alternative to 5Q0511115P as it appears to be only about 6mm longer with about the same stiffness. Being 6mm longer could be an advantage, because sometimes when owners fit 4 new springs the front end can end up looking slightly higher than the rear end. This for many is not a good look. So a 6mm longer rear spring might help, but I've no idea whether fitting the below 5Q0411105HC front springs and 5Q0511115P rear springs would make the front end look slightly high compared to the rear end. However, I would probably go for the below Japko springs as I believe they are rebranded KYB springs (ie. identical...notice how the 1107 and 7156 part numbers are repeated in both the KYB springs and the Japko springs)...so you get KYB quality at a much better price.

 

I believe Ashika and Japanparts are also rebranded KYB springs as again they use very similar part numbers and where quoted the specifications such as length, wire diameter, and outside diameter, are always identical. The photos always seem to be identical on Japko, Ashika, and Japanparts...which is another give away to the fact or strong suspicion that they are identical springs.

 

5Q0411105HC front springs

KYB RA1107

Japko ZCJ1107A (same as KYB RA1107, but can be much cheaper)

https://www.autodoc.co.uk/car-parts/oem/5q0411105hc?search=OEN 5Q0411105HC&supplier[0]=85&supplier[1]=10914

 

5Q0511115P rear springs

Sachs 994 924

https://www.autodoc.co.uk/sachs/13786055

 

5Q0511115Q rear springs
KYB RA7156

Japko ZCJ7156A (same as KYB RA7156, but can be much cheaper)

https://www.autodoc.co.uk/car-parts/oem/5q0511115q?search=OEN 5Q0511115Q&supplier[0]=85&supplier[1]=10914

 

Edited 28 September, 20232 yr by Carlston