Open Sky System suspension differences

MattSnap

Member
Hi there A2 Hive mind,
I have a question that I have been unable to discover after searching extensively through the suspension threads.

It relates as above to the differences in springs and dampers on open sky equipped cars.

Mine is a TDi 90 (which one might reasonably assume was on sport suspension with the 17" wheels) but in looking around for replacement springs and dampers, I am noticing suppliers listing springs/dampers as suitable or not suitable to OSS/Panoramic sunroof cars.

In the definitive suspension parts list I cannot fathom if there are part codes I have missed in searching for OSS specific parts, but I could just be overwhelmed with so much data.

For your information, I am thinking of going to Bistein B4 shocks front and rear (or possibly gas adjust rear shocks from KYB) with new top mounts all four corners, new bump stops and dust covers all round, new rear spring seats and Spidan 49527 rear spings and Sachs Coils for OSS cars up front.

What would be the advice fro those with OSS cars and the need for I assume more progressive springs to avoid sunroof flex and damage?

Many thanks folks,
Matt
 
Hi there A2 Hive mind,
I have a question that I have been unable to discover after searching extensively through the suspension threads.

It relates as above to the differences in springs and dampers on open sky equipped cars.

Mine is a TDi 90 (which one might reasonably assume was on sport suspension with the 17" wheels) but in looking around for replacement springs and dampers, I am noticing suppliers listing springs/dampers as suitable or not suitable to OSS/Panoramic sunroof cars.

In the definitive suspension parts list I cannot fathom if there are part codes I have missed in searching for OSS specific parts, but I could just be overwhelmed with so much data.

For your information, I am thinking of going to Bistein B4 shocks front and rear (or possibly gas adjust rear shocks from KYB) with new top mounts all four corners, new bump stops and dust covers all round, new rear spring seats and Spidan 49527 rear spings and Sachs Coils for OSS cars up front.

What would be the advice fro those with OSS cars and the need for I assume more progressive springs to avoid sunroof flex and damage?

Many thanks folks,
Matt

Spidan 49527 are front springs not rear springs. Avoid Spidan as too many owners have had breakages with them.

OSS cars use slightly stiffer rear springs compared to non-OSS cars.

I suggest you use KYB RH3243 front springs and KYB RH6594 rear springs for your 1.4TDI with OSS (or maybe the Sachs option that I have listed towards the end of this post).

KYB RH3243 Front Springs (£14.84 each on ebay).



KYB RH6594 Rear Springs (£17.21 each on ebay).



If you prefer Sachs springs (although they are a little more expensive than KYB), the following is an option:

Front Springs for 1.4TDI with OSS
Sachs 997854 (matches OEM part number 8Z0411105AL)


Rear Springs for 1.4TDI with OSS
Sachs 996940 (matches OEM part number 8Z0511115BB)

 
Last edited:
Thank you so much for the advice Carlston

I've added some information in my first post on Sachs springs.

Comparing the KYB and Sachs options that I've listed in my first post...

Both KYB and Sachs rear springs should be similar.

The difference is in the front springs.

The KYB RH3243 front springs should be softer than the Sachs 997854 front springs. So if you want firmer front springs go for the Sachs springs, and if you want softer comfort front springs go for the KYB. I haven't listed the firmer KYB front springs because a couple of owners with the 1.4TDI have complained of a slightly high front end when fitted with KYB RH1664 front springs (these are the firmer KYB front springs that I haven't listed above).
 
Last edited:
Thank you both for such clear explanations. Wonderfully detailed.


Sent from my iPhone using Tapatalk
 
So today I replaced the rear shocks, springs, top mounts, spring seats, bump stops and dust covers, and it now looks lovely and level.

Still have the front ones to do, but an improvement already.

The rears were original Audi monroe MN2 shocks. Bump stops and spring seats mullered on the right hand rear. Left a little better, although the left hand shock top needed brutal work to get it out.

ab24cc2beb0650c6ee9bc16392ad5ab9.jpg

8fe2ba5093c90c0f4ece3fb60d829a8a.jpg



Sent from my iPhone using Tapatalk
 
I suggest you use KYB RH3243 front springs and KYB RH6594 rear springs for your 1.4TDI with OSS (or maybe the Sachs option that I have listed towards the end of this post).
Would these apply for the lighter 1.4 petrol with OSS or not?
 
So today I replaced the rear shocks, springs, top mounts, spring seats, bump stops and dust covers, and it now looks lovely and level.

Still have the front ones to do, but an improvement already.

The rears were original Audi monroe MN2 shocks. Bump stops and spring seats mullered on the right hand rear. Left a little better, although the left hand shock top needed brutal work to get it out.






ab24cc2beb0650c6ee9bc16392ad5ab9.jpg

8fe2ba5093c90c0f4ece3fb60d829a8a.jpg



Sent from my iPhone using Tapatalk
A recent thread, on ride height, concluded that the level check should be made using the rubbing strake, under the doors, as reference measured to ground level. The logic of this is that the front rides higher than the rear, to ensure full suspension travel, and wheel movement. Think hard braking while turning ...
Yours looks a bit low at the front in the pic. Check strake to ground dimension before replacing the front springs. I love those 9 spokes!
Mac.
 
Thanks for this post @MattSnap . I didn't know suspension needs to be different with OSS. Yesterday i almost bought a losing suspension kit (25mm front and rear) for my A2.
Did somebody lower a 1.6FSI with OSS and good results? If so, can you tell me the correct setup?
Thanks!
 
Thanks for this post @MattSnap . I didn't know suspension needs to be different with OSS. Yesterday i almost bought a losing suspension kit (25mm front and rear) for my A2.
Did somebody lower a 1.6FSI with OSS and good results? If so, can you tell me the correct setup?
Thanks!

It was just that I noticed different offerings in springs at the rear for OSS cars, and got confused myself.

Thankfully the others on this thread helped clarify.

I’m really not sure what the difference is for Petrol v diesel variants of the A2.

Perhaps others can offer their wisdom.


Sent from my iPhone using Tapatalk
 
I believe that front suspension should be different because of the engine weight difference. But i saw that in a lot of place, the offer for the 1.6Fsi and the 1.4tdi are the same
 
A recent thread, on ride height, concluded that the level check should be made using the rubbing strake, under the doors, as reference measured to ground level. The logic of this is that the front rides higher than the rear, to ensure full suspension travel, and wheel movement. Think hard braking while turning ...
Yours looks a bit low at the front in the pic. Check strake to ground dimension before replacing the front springs. I love those 9 spokes!
Mac.

Cheers Mac, the front end was highlighted with weeping shocks at the MOT, so the next thing to do is a weekend on the front end. Previously it looked like a gasser with the front end pointing skyward. Now it’s more level, but the new shocks, springs, top mounts and drop links should sort the front out too and make the car almost like new.
Whilst I have the osf suspension off I’ll do the cambelt , water pump, and the oil pump and timing chain.

With the left off it’s DMF and six speed box time.

I’m enjoying making an £1100 car into a tip top one.

It’s good fun and this forum is incredibly informative and helpful.

The 9 spokes will be refurbished in due course. But best price I’ve seen is £60 a corner.


Sent from my iPhone using Tapatalk
 
I believe that front suspension should be different because of the engine weight difference. But i saw that in a lot of place, the offer for the 1.6Fsi and the 1.4tdi are the same

Interesting I didn’t know that.
I’ve gone for KYB springs as per the earlier part of the thread and Bilstein B4 shock/struts.
Rears are kyb springs and shocks. It already feels more together at the back end. Raised it about 50mm but the old shocks and springs were absolutely shattered.


Sent from my iPhone using Tapatalk
 
I believe that front suspension should be different because of the engine weight difference. But i saw that in a lot of place, the offer for the 1.6Fsi and the 1.4tdi are the same
Each different OEM spring part number was designed to handle a given weight range, which are identified by the coloured dots painted on them. The 1.4 engine head and block are made from alloy and are relatively lightweight. On the 1.6 though, while I'm not sure about the head, at least the block is cast iron the same as the 1.4 TDI engine, it's certainly much heavier than the 1.4. So the 1.6 needs front suspension in a heavier weight range than the 1.4, but that specification is also sufficient to handle the TDI.
 
Would these apply for the lighter 1.4 petrol with OSS or not?

KYB RH3243 front springs are listed for the 1.4 petrol with or without OSS.

KYB sell them to replace OEM part number 6Q0411105AN

Kilen, Lesjofors, and Eibach also list front springs to replace this OEM part number.

However, KYB seems the best price on ebay out of these brands.

KYB RH3243 front springs (for 1.4 petrol with or without OSS)

KYB list rear spring RH5514 for non-OSS

KYB list rear spring RH6594 for OSS

The OSS rear spring will be slightly stiffer than the non-OSS rear spring.
 
Last edited:
I went for KYB RH 3243 at front with Bilstein B4 front struts, and monroe top shock mounts with meyle hd drop links- still to be fitted (along with new cast a arms bushes and bolts).

Rear went KYB RH 6594 rear springs, with new KYB gas-a-just shocks new top mount units and KYB dust covers and bump stops, with new febi rear coil spring seats.

I did the rear discs pads and bearings a month or so ago. Will review front end bearings during reassembly of front end, which might be done before Friday. The rear end feels way better already, highlighting the worsening weeping front struts since MOT in October and a clonk from OSF drop link.


Sent from my iPhone using Tapatalk
 
Back
Top