Fsd spring mystery - help!

KneesUp

KneesUp

A2OC Donor
I've just had FSDs fitted to my late-2003 TDi, with Weitec -30s on the front (no spring pre-compression), and with what I understand from Skipton and Audi to be Audi Sport springs on the rear (8Z0511115BC - three white dots and two orange).

Skipton reports that on his car, with a similar set-up, it rides 'dead-level'. Others say the same. And that makes sense because if FSDs raise the front 15mm, and the Weitec springs lower the front 30mm, the net effect will level the car to the same height as the rear Sports springs which are effectively -10s, I am told, give or take.

I am also told by Schnelletrecker and others that the rear FSDs do not raise the ride height as they do on the front.

Well.... Something's very wrong on my car. Can anyone suggest why?

My front ride height is fine - not super-low but better than stock. But the rear sits with its arse in the air, riding about 15cm higher than before on stock SE springs. It looks mad and something ain't right. I didn't fit the springs but there seems no area for adjustment.

Ideally, I would re-fit the original springs and see if they leave the car sitting even higher. Then I know it's the FSDs that are causing the problem. If they sit the car lower, I know it's the springs. But I can't help feeling I am missing some basic point here because no-one else I can see has reported such a problem.

I also don't like the ride quality. It seems oddly 'bouncy'. The bottoming out and crashing has gone, the car corners flatter (but it wasn't bad on stock stuff) and the ride is firmer but not in the controlled way I was expecting. I think it's all connected to this rear ride-height issue.

Can anyone offer any advice?

Many thanks.

Richard
 
Hi, obviously your new rear springs are not the right rear sport Audi springs version.

It seems you've purchased rear springs that come with much more spring rate than usual. Please install your original rear springs for a trial and error ride session.

If the car's rear still is lifted by 10 to 15 cm (wow!) then your rear FSD shocks seem to feature an unusual super high amount of static gas pre-load (that would be a very wrong damper setup). So have you by chance tried to compress the rear damper rod manually before installation? Was it very difficult to push the rod into the case completely? If so then Koni has to replace your rear shocks for free.

Last question: Are the rear seats mounted currently? The A2 is considerably better to drive (also in terms of comfort) with some weight in the back leading to a more neutral weight distribution between front and rear axle.

Generally good shocks require a few thousands of miles to break-in properly.
 
S, Thank you, as ever, for your kind and detailed response.

My rear seats are fitted and the car has BOSE as standard and a factory spare wheel, so there's plenty of weight there.

I have double-checked the part number and the colour-coding and they are correct springs as per Skipton's advice (and fitted to his car, I believe). However, they may be an badly-made batch. I will re-fit the standard springs and check the shock compression as you suggest - or ask Stealth Racing to, who I am seeing in a weak for another job.

Many thanks.

Lee and Skipton's advice would be much appreciated, too, as they have gone down this route.

Many thanks to you all.

Richard
 
Hi Richard.

I have not yet got round to buying, let alone fitting the standard Audi Sport springs to my car, so I think Mike may be better placed to help or I believe a couple of others that have fitted them (a2sumo and dan_b I think??).

Have a look at this thread and some of the other threads linked from it too.

http://www.a2oc.net/forum/showthread.php?t=11031&highlight=rear+springs

I will definitely be changing my rears to experiment, but have other things on my plate at the moment, such as wheels that don't fit, tax, MOT, ARB plans, etc, etc.

Sorry I can't be of any more help.

Cheers,
 
Well when i first fitted my FSD's the height was a lot more than STD but some weeks later they are settling down to a much better height, i noticed this on a view of the car plus, my car use to drag it mud flaps as i pulled out the drive, but after fitting them it stopped for about 3 weeks then it started to do it again

Phil
 
Thanks Lee. I had seen the link you refer me to and my car sits up higher at the back than the car illustrated with only its front Springs changed. Goodness knows how exaggerated my problem would be with the SE springs back on...

I spoke to Vince at Stealth racing about it today as I'm going up there for some engine work next week. He asked me to check my bump-stop specs, which I have and they're fine. He also said that he's had this problem a number of times before with FSDs- that their ride heights are very inconsistent. This makes a lottery-mockery of all the careful calculations that have been discussed on this forum for ages. And apparently Koni don't want to know...

If it is an FSD problem, I guess I'll have to try and overcome it by pre-compressing the Sport springs I've bought, or risking Weitecs on the back. But I'm not at all sure what the outcome will be. It all begins to feel like a bodge. And the car just isn't riding right either. The vast majority of people rave about their FSDs - I can't do that yet, cos it just doesn't feel right...

Maybe Dan and Mike and others will have insights?

Many thanks again.

Richard
 
It also could be worth a shot to ask if someone that had the -30 rear Wietecs spare if you could try them, like Dan b and Alanm (if they still have them)

Cheers Phil
 
hi knees up i really cant shed any light as to why your rear is so high? all i will say is that the SE springs weren't silly high in combination with front weitecs-but the car still had a floaty feel to the rear.when i put the weitecs on the rear yes it is slightly to low BUT the handling was very sporty:D that is why i really recommend the rear springs.agreed i have not tried sport rear springs and yes skipton01's does sit nice and level,but just on a cost factor i wouldn't buy Audi rear sport springs(unless second hand).another point to remember is my car is an fsi which has a lighter load on its front axle compared to the tdi,so even with sport springs on the rear it may not sit right.in fact my friend a2bluesport(stock sport sus fsi) his still sits lower at the back by 10MM-15MM.
i think it is worth swapping your new springs for the original SE springs and see if it is the rear shocks at fault.
good luck mike
 
If your rear is really 15cm higher than it used to be, then I'd suggest that the springs wouldn't stay in place, as you normally can remove them by hand (strong hands admittedly) when the rear axel is at full extension.

The part number is correct, as are the paint marks and what amazes me is the height you report - can you post photos please?

As Schnelletreker suggests, it may be improperly gassed dampers to blame, or even some really bad installation.

As you mention, I have -30mm Weitec fronts and standard sport rears, mated to FSDs and my A2 (with Bose and a spacesaver) rides nice and level, so something is really amiss.

Cheers,

Mike
 
with my experience i wouldn't go for weitecs on the rear, stay with stock springs. Visually it does sit a little low but it is more the ride implications. I may change back to standard springs at some point.
 
been thinking about this all evening----the only other way i can think of fitting the rear springs wrongly would be to fit them upside down? so that the rubbers get hung up on the location pins? but i would have thought they would be really hard to fit like that----or did you fit new rubber spring perches and one or both old rubbers still on the car/axle? please post some picks.

just a bit of fitting advice to people fitting fsd's when fitting the rear dampers don't do the lower mount bolt up tight with the axle in the fully dropped position--let the car down and then do them up.this helps the lower bushes last longer as they are not all twisted up.;)
 
KneesUp said:
My front ride height is fine - not super-low but better than stock. But the rear sits with its arse in the air, riding about 15cm higher than before on stock SE springs. It looks mad and something ain't right. I didn't fit the springs but there seems no area for adjustment.
Click to expand...

Six inches higher than standard! That must look like some crazy Hot Rod! LOL
 
I have the Weitec 30 rears available and I also have my stock SE rear springs too which seem im decent condition which youre welcome to buy if you like . One thing I have seen like this before with the rear ride being pushed up and a strange ride behaviour was the rear anti roll bar had been installed upside down so the car was effectively riding on the ARB not the springs. Now in your case Im not suggesting its the ARB but I might suspect the rear shocks havent been fitted correctly? My Fsds are lovely and with Weitec 30s at front and Audi Sport springs at the back my ride height is lower and bang on flat...
 
Thank you Mike. I'd been following your thread and all you say makes sense. Seeing as my SE springs are off the car I'm tempted to have them pre-compressed by 20mm before offering them up again. That will take up the initial 'give' and so create some stiffness, while lowering the height (without going Weitec radical and pooping-elk!). What I don't quite understand is how the shock absorbers affect height in relation to the spring height. ie, which does what.

What I don't want to do is keep swapping springs around as I have no tools, no time and no garage - I have to book it into a mechanic's and it gets expensive and boring. Also, I bought the FSDs second hand but un-used so have no meaningful receipt. I doubt Koni will be interested, so somehow I have to make this work...

Thank you for your thoughts.

Richard
 
Sorry gents, I briefly overlooked all your replies so my last posting only referred to one. All your comments are greatly appreciated.

Firstly, my mad mistake - I meant 15mm, not cm... too high. In other words, had I left the SE springs on I wouldn't have expected the ride height to change, but it is 15mm higher than before. Therefore I would have expected it to sit 25mm lower (2.5cm) than it does at the moment with the Sport springs fitted. I'll try and post some pics tomorrow.

Considering all that has been said I suspect it's the FSDs that are wrong. The springs are not fitted wrong (looking at them I'm not sure how they could be). The FSDs might be in some way, but that will need further insight. I didn't fit them personally.

I have no ARB to the best of my knowledge.

I'm not keen on going the rear Weitec route but I have my old SE springs, so may have to look at pre-compressing those around 20mm as per my previous posting before refitting them. Not having a receipt for my FSDs makes tackling Koni that much harder, and it costs money to keep taking these things on and off anyway...

I really appreciate everyone's help. Top Club and support. Thank you very much all. Photos to follow.

Richard
 
Just gor my A2 back yesterday from my mechanic : FSD's and front Weitec's -30 fitted. I've not measured the ride height, but the rear does not seem to have raised significantly.
Oddly, it's the front end that is now higher than before, when it was supposed to have been lowered by 30mm ! But after a few kilometers it has already settled down, but not yet as low as it should be.
I will wait a few weeks and see how it goes... Apparently it's usual, and I think it will be fine and level.
Damping with the FSD's has been much improved :)
 
Thank you fbi for your insights. That's all really interesting and useful.

At the very least it confirms that the FSDs need time to 'settle' (and other posts talk of a 2000kms running in period, too) and that the rears shouldn't lift (as per Schnelletrecker's and others posts), even if the fronts do a lot.

The implications of all these variables seem quite important and I will do my best to summarize my findings when the problem is - hopefully - solved. What seems certain though is that all FSDs are not the same, which confirms what Vince at Stealth racing told me...

Richard
 
I'd still like to see photos of the result you have though - please post a couple if you can.

Cheers

Mike
 
You must log in or register to reply here.
Back
Top