tuning info - part 1 suspension

[dunk]

i have been doing a lot of reading and phoning to find whats available for non-track improvements - i am looking from the road car angle that you would take your wife/kids out in, rather than the bone-shaking track demon mods and here's a summary:

the standard /SE suspension seems ok but the damping isnt great and the springs and a little hard, and it sits too high with too much understeer.

springs
sport is -15mm compared to standard
s-line is -25mm
S3 is -35mm

aftermarket springs - millions to choose from but main one are:
h&r -35mm
eibach sportline -30mm
eibach pro kit -45-50
weitec -40
kw -40

if you go lower you get more static negative camber (good) but lose camber gain in roll, so that the -45 to 50mm drop seems to have used up all the negative camber available at the front.
also, the pro kit seems to rub/catch occasionally particularly with wider wheels or lower offset wheels

popular opinion seems to favour the eibach sportline or h&r

dampers
loads to choose from, some adjustable. i have had adjustables in the past and always had them left at the factory default, or fiddled endlessly rather than driving the car, so i was looking for good but fixed damping for road use to fit and forget.
koni, weitec, h&r etc etc
popular option from people who have tried favoured the koni fsd which give a great quality of ride with good damping and handling when needed
the fsd dampers have a small assist spring inside that tends to push them out which can mean a car doesnt lower quite as much as expected (this is only a few mm so doesnt seem to be particularly important) they are highly rated when used in combination with the eibach sportline -30mm springs.

ARBs
increasing the thickness of an arb increases roll resisance in proportion to the 4th power of the diameter, so small changes make a big difference. audis are set to understeer by design, and increasing the proportional thickness of the rear with help to reduce understeer and eventually provoke lift-off oversteer (controllable with the ESP anyway)
an increase of front roll stiffness will reduce roll, promote stability and turn-in but the rear needs to be increased by a higher factor - probably about 1.5 to 1.8 times the front increase
my sportback 2.0tdi comes with front 21.7mm rear 20.7
fr =increase in front stiffness, rr = increase in rear ratio,
r:f = rear to front relative increase
options include:
make front rear fr rr r:f ratio
h&r 1 26 22 2.06 1.27 0.6 - more understeer
h&r2 28 24 2.77 1.8 0.65
neuspeed 25 25 1.76 2.13 1.21 good choice but £400
kw /eibach 26 2 2.06 1.52 0.73
golf r32 front 23.6 1.4 1k0 411 303AL only £75

golf front
neuspeed r 23.6 25 1.4 2.13 1.52 possibly the best choice

negative camber
more negative camber at the front will improve turn-in and increase front end grip and reduce understeer dramatically. -1.5deg to -1.75 deg is fantastic and wont kill your tyres if the tracking is ok. the rear needs less, probably about -1deg each side. the rear is factory adjustable
lowering the car will give you some negative camber, but too low uses up the gain in negative camber in roll. 2 options to increase front negative camber more:
1) morego do altered bottom suspension arms - -1.5 to -1.76 deg on an exchange basis, fitted at £495 for the golf 5, and these fit the a3
2) adjustable top mounts from k-mac give adjustable camber and caster and can give upto -3mm negative camber, they can be adjusted on-car easily. they cost about £160 delivered from the australian manufacturer and simply replace the factory top swivel for standard springs/dampers or coilovers.

so after all this, my SE now has:
eibach -30mm springs
koni fsd dampers
neuspeed ARBs front and rear, soft setting at front, stiffest rear
k-mac adjustable plates -1.75deg front, -1 at rear

the suspension is more comfortable than SE on potholes and broken tarmac, far better handling at high and low speed, better turn-in, the understeer has gone and it looks a lot better stance without being too low.

 

[lil_coz]

Damn! Covered all your options didnt you? Got any piccies?

 

[Angry Beaver]

Very interesting Thanks
I have installed Neuspeed lower springs and rear swaybar on my A3 but still feel it is a bit of a lead tipped arrow.
Was considering camber adjustment so after reading this that may be my next step.
Did you notice much of a difference after the camber change?

 

[SteveTDCi]

good review, I must admit that if I change the suspension Koni FSD's and eibachs would be on my list, i've used eibachs before and find them very good in terms of ride and handling. I also fitted a strut brace to my Focus and that made a noticable difference.

 

[N8]

I'm getin KW V2s and H&R anti roll bars for mine

 

[dunk]

the camber change is vital to getting the big ARB to work - on their own the ARB upgrades work, but you need more front end grip

as an aside, the eibach sportline -30mm springs resulted in approx -1 deg front camber but -1.5 rear

you need to get more front neg camber but still have some more camber in roll, ie dont lower too much.

aim for at least -1.5 at the front, preferrably -1.6 to -1.75

 

[baz1985]

impressive stuff.

Where did you get the equipment from and fitted?

 

[dunk]

ARBs, springs and dampers inc fitting from awesome gti
best price on koni fsd i could find, and nobody else sells the neuspeed arbs anyway...

k-mac adjustables direct from k-mac in oz -

 

[skodaudi]

Interesting write up.

So the Sportback comes with a rear ARB as standard? Didnt realise that.

I put an uprated rear ARB onto my Fabia vRS and it made a MASSIVE difference (well it didnt have one in the first place!)

 

[baz1985]

ARBs, springs and dampers inc fitting from awesome gti
best price on koni fsd i could find, and nobody else sells the neuspeed arbs anyway...

k-mac adjustables direct from k-mac in oz -

Thanks mate.

I am thinking of doing similar, but going for coilovers as I've never had any before.

KW Variant 3
Neuspeed ARBs
K-MAC camber adjust kit

But I'm in negotiation for an E92 335i at the moment, so it might not happen.

 

[dunk]

you're welcome - my rs4 had coilovers but the level was set too low and the threads were locked by the time i came to adjust them!

people seem to think that coilovers are magically better, but they are only springs and dampers with adjustable ride height - comes down to matching of springs rates and dampers for the intended use, and mostly damper quality.

the neuspeed arbs and k-mac camber kit make the biggest difference, but i have to say the combination of eibach springs and koni fsd dampers is such a great match for road use - its far more comfortable than the SE but streets ahead on the twisty back roads - we have everything from cobbled streets to really twisty b-roads round here and the car's a hoot to drive now.

 

[baz1985]

Well, I've gone for:

KW V3
H&R Sway Bars

To be fitted at Awesome on the 29th.

Hopefully, it'll be worth it.

 

[George K]

Dunk

I had been researching the best ways to obtain negative camber, and probably for reasons similar to yours came across the K-Tec top mount and decided that it appeared to be a much better route than lengthening the bottom arm (less risk of drive shaft joints running in the wrong part of their tracks, steering arms having less thread engaged, etc). I then decided to Google it for any UK feedback and immediately found your post of 30 Jan 2008 . I must say that I was very impressed by all your reasoning (lowering the ride height too much does have the effect that you describe, as well as moving the roll centre quite a long way down, possibly below ground level - and also running the risk of bouncing off the bump stops when cornering very hard – a real no-no).

My particular interest is that I am thinking of buying one of the current generation of VAG FWD 2.0 litre diesels for use as a road car and also for hill climbing – however living in rural Devon it must still be able to cope with the rough local lanes. The attraction is that it will be eligible to run in the up to 1,400 cc class – obtaining reasonable power does not seem to be an issue, but sorting the handling is far less well documented!

I wonder if I might ask a few questions:

Were the mounts easy to install and do they give the claimed range of adjustment?

The information on their website mentions that they may raise the ride height by up to 6mm – is this correct?

Having increased the amount of negative camber have you changed the toe-in/out? Might I ask what setting you run?

Do the Koni FSD improve ‘roll damping’?

Any help very gratefully received.

Regards

George K

 

[dunk]

the mounts are easy to install, particularly with lowered springs (you dont even need spring compressors) they simply replace the normal top mounts - i removed the whole strut and then simply unbolted the damper top and swapped over the mount, then put it all back together of course. before you start, make a note of where the damper top nut is in relation to the suspension turret hole under the bonnet, then you can get the suspension back together roughly at factory settings, then do a 4 wheel alignment later.

the audi a3 ones dont change the ride height at all - i phoned the company about that.

they give a huge range of adjustment - the mounts are made eccentric so you can mount them for either more negative camber or more castor but each way round gives a good range - the way i fitted them gives me upto -3deg negative camber and plus or minums 1 to 2 deg caster.

i have recently made some more changes - i previously set the caster at 7deg - factory standard with zero front toe - the car had the usual audi vagueness about the steering centre. the factory settings for quattro s3 suspension include caster at 8deg with 0.5 deg variation allowed.

so i set mine to 8deg 20 minutes caster with the factory 5 minutes toe in at each wheel, with -1.65 deg negative camber - what an improvement.

its lost the vagueness in the centre with a strong self centreing action and the negative camber really helps the front end to grip so reducing understeer.

rear is set to zero toe with -1.0deg negative camber (factory is 1deg 20minutes) with some toe in.

one word of caution about the top-mounts - with the camber wound up, the spring mount is very close to the mount that bolts to the strut top and unlike the factory mount there is no rubber coating - under hard knocks the top spring plate clunks against the rest of the mount creating a knocking sound due to the lack of rubber.

i added an addition washer to space the spring plate away from the rest of the mount an d this drastically reduced the clunking (it also raises the ride height by the thickness of the washer so mines now about 1.5mm-2.0mm higher at the front but you would never guess) if i take it apart again at some time i would add a sheet of tyre inner tube rubber between the mount and the bodyshell where they meet/bolt together to replicate the factory sound insulation

the koni fsd dampers are excellent - mine was an SE spec and mine is now at least as comfortable if not better, without the factory crashing and much better dynamics - cant say whether they improve roll damping, but i have neuspeed front and rear 25mm ARBs set on the hardest to dont have any roll to speak of.

 

[George K]

Dunk, thanks very much - most interesting and helpful. My current hill climb car is a Cliio Trophy - the suspension settings are so different that I can see I shall need to learn all over again.

 

[Teejay]

Just had a (standard) rear spring snap on my 2.0Tdi non-quattro.

Obviously need to get this replaced ASAP. Luckily car is just about driveable as it has only snapped about 3/4 coil from the end (car now 30-40mm lower on that corner).

The info above is really useful, but think you've got the Eibach Pro-Kit and Eibach Sportlines the wrong way round. prokit is -30mm (ish) and Sportlines are -40to50mm (ish).

You say you bought -30mm Eibachs, but is that Prokit? Or did you get the drop wrong because you already had an SE and they were Sportlines at -45?

Cheers,
Tim

 

[Teejay]

Is there anything else I need to replace when changing the springs (all round obviously)?

 

[dunk]

yes you are right, a typo about the pro-kit and sportline the wrong way round

anyway, to swap the springs you just need new springs (and time/money to do the swap)

the labour to change the springs is the same as swapping the dampers as well, so its a good time to think about changing them as well for only the cost of a set of dampers.