Problems with Koni shocks - rear

[scillyisles]

Just wondering if anyone has the symptoms I'm getting using the Koni suspension upgrade where the rear shocks when going over speed bumps or road irregularities produce a slamming down sound from the rear. Dealer has adjusted them from fully hard to fully soft and we can't get rid of the sound. Currently the rears are set at 1/4 from hardest and still it happens. I also tend to get bump steer from the rear if the bumps are really bad on a corner.
I've got the same Koni suspension as others on here with new upper and lower wishbones at front and rear, rear Powerflex anti roll bushes. Car has been fully four wheel aligned and corners well if the road is smooth.
If I can't get it sorted them I'm going to change the rear shocks back to standard ones or try the KW suspension alternative.
Any help/advice greatly appreciated.

[alastairg]

No such problems with mine at 1/4 from softest. Excellent compromise. Are they fitted correctly ? Could it be poweflex bush noise (many have reported this). A faulty shock ?
I have had konis on 4 performance cars over the years with no problem.
Maybe worth a post on S2 forum

[GlynRS2]

I hope it is an isolated problem as I am just about to do the same upgrade as you did earlier in the year - Big Red factory brake upgrade kit, Koni adjustable dampers & new OE bushes alround. Did you replace the rear top mounts at the same time?
What is the KW alternative? I have not come across that one before. Generally KW are very highly rated. I thought they generally used Koni dampers in their kits though.

[alastairg]

One option Glynn is to check prices with vagparts re OEM spec dampers. They were developed for the car and may be an answer. Saves trying to guess the best setting!

[GlynRS2]

I have considered that - and looking on my ETKA, works out about the same price. I was hoping for a bit more damping control than standard. Of course it may just be I need new dampers.
I found the KW kit - height adjustable coilovers with damping adjustment work out about £1300 outright or £1000 exchange from www.Motorsportworld.co.uk.
I don't really want to lower the car or go too stiff on the suspension, so will probably go with the Koni dampers.

[super-g]

What you have are the wrong Koni’ s for your standard spring, you need to check the spec that was on the box when you bought them.

Two sizes are available 25mm or 50mm rebound. This means the damper has a stop inside to allow for longer or shorter travel making the open length 25 or 50mm shorter, mainly used when lowering a vehicle to ensure that the shorter spring does not dislocate. You have the reduced 50mm travel, which will not work correctly with standard springs as it has 50mm less travel so thumbs as it hits the stop inside the damper.

I had the same problem when I had some fitted to standard spring by Kim Collins who has not got a clue when it come to setting up suspension, (probably the wiser now thought) so I had to work out what he had done and better still resorted back to the standard Porsche setup which is perfect, it’s the front end you want to concentrate on and I will post details soon.

Hope this helps.

best

If you want to start by upgrading the front bushes to powerflex first, I am selling them on ebay.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... %3AIT&rd=1

[scillyisles]

Thanks super-q.
I have Koni dampers (externally adjustable rear); Front 86-2086 SPD1, rear 8210-1160Sport on my car that I ordered from MotorSportworld. Others seems to have ordered the same dampers and yet don't seem to have this problem - I must have been unlucky.
Is there a different code for the shorter travel ones or do you have to explicitly ask for the longer travel ones?
I'm going to probably change back to standard rear dampers as that's probably the most cost effective thing to do.

[super-g]

The rear damper part number 8210 1160S is correct, but on the box you should have a rebound value, the normal setting is 25mm but I still do not recommend using as you will still get a lesser thumb, zero rebound is best.

One reason for using these Koni dampers is you can strip down and re-calibrate if you have the equipment or know the setting.

As mentioned previously the standard Porsche setup is perfect for the road the problem with all sports suspension is the hard springs and rubber bushes and the mount of rubber used on the suspension.

You have nothing to worry about on the rear just make sure you have new rubber top wishbone bushes, only fully tighten when the car is sitting fully down, camber is 1 to 3mm max with 2mm degree best for good turn in, the toe should be zero.

Don’t listen to any one about under steer or over steer when it comes to toe, you do not adjust toe to achieve these setups correctly, it is achieved by adjusting camber/track and tyre size/profile but still always using zero toe.

Using toe settings to achieve this will be at the expense of making the car very twitchy in the bends if grip is lost, it has some uses on a rally car set up preferred by some drivers but not for use on tarmac, this setup just creates forces outside your control.
Adjusting the toe to achieve over steer or under steer for tarmac use can liken the driving experience to driving on ice.

If you are getting a lot of back thumbing on reasonably smooth A roads from the drivers seat it is certain that or have either worn top wishbone bushes or a toe problem. The toe can also be checked by reading the tyre wear a very useful skill, if rear bushes are worn the car can suddenly turn-in/out when going round a bend.

Front Koni 8610 1262S top adjustable are best with the ability to strip down and change the foot valve, also see these fantastic top mounts which gives great four wheel drive power slide control. See pic.

Always remember with sports suspension you are starting of with a very hard spring which determine the hole balance of the car, the dampers just add a little more initial resistance but mainly stop the bouncing it’s the spring that control 90% of the forces, that’s why you don’t need to fit harder spring, if you go harder start thinking about a full race harness to hold you in the seat, the Audi spring are about the best compromise.

If you want to talk about me supplying and setting up your car please contact me, you will be able to drive my RS2 first.

Best

Talk soon

[GlynRS2]

I have decided to stick with the standard OE dampers & replace all the bushes with new OE ones at the same time.
I have had a very good price from VAG Parts. Would be very interested in getting a comparable quote & may need help setting it up etc.

[alastairg]

The rear damper part number 8210 1160S is correct, but on the box you should have a rebound value, the normal setting is 25mm but I still do not recommend using as you will still get a lesser thumb, zero rebound is best.

One reason for using these Koni dampers is you can strip down and re-calibrate if you have the equipment or know the setting.

As mentioned previously the standard Porsche setup is perfect for the road the problem with all sports suspension is the hard springs and rubber bushes and the mount of rubber used on the suspension.

You have nothing to worry about on the rear just make sure you have new rubber top wishbone bushes, only fully tighten when the car is sitting fully down, camber is 1 to 3mm max with 2mm degree best for good turn in, the toe should be zero.

Don’t listen to any one about under steer or over steer when it comes to toe, you do not adjust toe to achieve these setups correctly, it is achieved by adjusting camber/track and tyre size/profile but still always using zero toe.

Using toe settings to achieve this will be at the expense of making the car very twitchy in the bends if grip is lost, it has some uses on a rally car set up preferred by some drivers but not for use on tarmac, this setup just creates forces outside your control.
Adjusting the toe to achieve over steer or under steer for tarmac use can liken the driving experience to driving on ice.

If you are getting a lot of back thumbing on reasonably smooth A roads from the drivers seat it is certain that or have either worn top wishbone bushes or a toe problem. The toe can also be checked by reading the tyre wear a very useful skill, if rear bushes are worn the car can suddenly turn-in/out when going round a bend.

Front Koni 8610 1262S top adjustable are best with the ability to strip down and change the foot valve, also see these fantastic top mounts which gives great four wheel drive power slide control. See pic.

Always remember with sports suspension you are starting of with a very hard spring which determine the hole balance of the car, the dampers just add a little more initial resistance but mainly stop the bouncing it’s the spring that control 90% of the forces, that’s why you don’t need to fit harder spring, if you go harder start thinking about a full race harness to hold you in the seat, the Audi spring are about the best compromise.

If you want to talk about me supplying and setting up your car please contact me, you will be able to drive my RS2 first.

Best

Talk soon

With regards to this type of top mount. Are you going to run into problems with metal fatigue in 'suspension turret' with hairline cracking as per rally cars ??
I have a set but have hesitated to fit them

[super-g]

Absolutely not. These aluminium top mounts will not fatigue the strut mounting point, they are fitted tightly to the body so move with the body, if the forces are great enough it good go through the top fixing point as would the standard if you were generating forces similar to a WRC rally stage but for the road use there is no way this could happen any more so than the standard ones.

I avidly followed Audi through the 80s starting with my first Lombard Rally in the mid 70’s at Sutton Park and all the Forest stages. (What great days compared to today’s corporate and nanny state control) but did not see anything else other than rubber top mounts used, even the Audi S1 Quattro Sport used rubber. On take off and landing you can even see the suspension move all over the place as it tried to located it’s self in the top mount housing. Audi would not use this suspension design today. I would like to see any evidence of other top mounts been used by Audi in their 80’s rally cars.

All the best suspension setups do not have much or any rubber in them, that includes a good comfortable road setup but it means that the suspension design and particularly the dampers and springs need very special tolerant control.

Will add more when I get a chance.

Best

[alastairg]

Absolutely not. These aluminium top mounts will not fatigue the strut mounting point, they are fitted tightly to the body so move with the body, if the forces are great enough it good go through the top fixing point as would the standard if you were generating forces similar to a WRC rally stage but for the road use there is no way this could happen any more so than the standard ones.

I avidly followed Audi through the 80s starting with my first Lombard Rally in the mid 70’s at Sutton Park and all the Forest stages. (What great days compared to today’s corporate and nanny state control) but did not see anything else other than rubber top mounts used, even the Audi S1 Quattro Sport used rubber. On take off and landing you can even see the suspension move all over the place as it tried to located it’s self in the top mount housing. Audi would not use this suspension design today. I would like to see any evidence of other top mounts been used by Audi in their 80’s rally cars.

All the best suspension setups do not have much or any rubber in them, that includes a good comfortable road setup but it means that the suspension design and particularly the dampers and springs need very special tolerant control.

Will add more when I get a chance.

Best

It was not Audi but WRC cars. I had heard from a source that after a rally or two that the suspension turrets on occasion suffered cracking.
Clearly the concept is sound to make the damper/spring 'work for their money' but I had concerns over a standard road car.
I would like to hear from anyone who has run these solid type topmounts for a few years with a heavy car with sports suspension on UK roads !
I am in no way critical of the concept. I just need a little convincing about using them longterm

[super-g]

Don’t worry about critising Audi we don’t want them resting on their Loral’s.

Believe it or not you have more steering thumb and vibration with the standard rubber ones. The alloy top mounts are fixed tightly to the body so cannot bounce about like the OEM ones. When the weight of the car is on a standard mount it is heavily compressed, over time the metal frame will collapse with the constant thumbing and free movement. This design is bad engineering at best that has no place on a performance car and certainly not from a manufacturer who prides itself on the phrase “Vorsprung durch technik”.

Audi is starting to improve its suspension partly due to specialists improving on the factory setup, even motoring journalists voicing their opinions all helps.

Secure fitting top mounts transform this car into something feeling more like a sports car, there is no way the standard top mount can compare, the hole steering feel is improved, turn-in response is just one improvement, you find yourself placing the car with more confidence, power slides or oversteer are corrected instantly with no delay from the steering, impossible to control with confidence using the factory setup.

When you have an engine that allows you to max the car you need precision steering and suspension to match.

The Audi 80-90 series take their steering and suspension setup from the early Golf’s and Audis when their cars were much lighter it worked.

The steering nervousness is a trait on all Audi 80-90 models something powerflex bushes with these top mounts overcome. Tiff Needell used harsh words to sum up the steering and suspension setup on the TT as well have others, they are not making it up, giving praise when praise is due is a good thing but too many manufactures announce design faults or weaknesses once a car is in production expecting the customer to pick up the tab etc!

I used to say, “I love this car but don’t recommended it” now “I love this car and can recommend it”!

Any one interested in purchasing with setting up please contact me for a test drive.

Talk soon

G

PS. Good news for Audi RS4 owner’s wheels is one example. The reason for this happening in the first place I find hard to believe, what’s happening to R&D.

[scillyisles]

This problem is now solved - I've reverted back to brand new OEM shocks on the rear and the problem has gone away. I've still got Konis on the front and my Audi dealer fitted Powerflex ARB bushes at the front.

[AAH!]

I recently fitted koni's with new standard springs all around and luckily I have not had any issues with the rears bumping.