Top Mount Saga continues

[philj]

Mercs were well known for isolating the road surface from sensitive ears and fragile bottoms. Just a thought.

Take one look at any post 82 Mercedes suspension and you'll see why it drives/handles/isolates better than an Audi. Nothing is stressed as the bushes are twice the size, long inboard springs, lots of caster, decent camber change on the front and excellent on the rear, huge lock. Best of the pre 2000 era in my opinion, it's a shame the old ones have a steering box, and the newer ones with racks are ugly.

The top mount issue was a large part of why I went towards the C4 chassis in the end, improved in the top mount and most other areas, but still well behind in suspension design. Isn't it the same as a 70s 100?

How does everyone find the B/C5 chassis for handling?

As for the B3/4 top mount, it's the same issue as the Polo. Half the weight, same top mount, and it eats through them in the same time.

Only options are, chop the turret off, or sacrifice a bit of ride quality.

http://www.maxrpm.de/Adjustable-camber-plates-for-VW-Polo-1-2f-Audi-50

[Monkeymagic]

So the mount on the right, what is it?? It lloks to be a nice machined bit of kit. Similar to what Kev ambridge was trialing

[philj]

That's by a chap in Germany called Salzmann, he doesn't make them anymore, and they're for a Polo with an M12 strut, so would need modifying, but the idea is there.

[Monkeymagic]

I guess its mk1 2 and 3 polo.looking at those struts?

[bikerjim]

So potentially mk4 topmounts could be used with lowering spring caps to give an almost standard ride height?

[Error404]

Steven I've not bought any bearings for them, just the mounts themselves to see if I could make them work. They are not a direct fit, but not hard to make them work. Must be a year since I did this need to dig them out to have another look
The are a similar design but more substantial and the bearing is bigger.

I really think you'd need coilovers to achieve standard ride height, the MKIV platform mounts are a good bit taller than the B3/B4 mounts.

[Error404]

Here is a quick pic of what is required. Pretty easy. The OD needs trimming down to match the OE B3/B4 dimension.

[quattrostyle]

Damn they are tall

[Monkeymagic]

Im going to order some black powerflex ones ive got some bearings and ill order the retaining nut with a collar and im going to give it a try. I believe. They will raise the ride height 15mm so ill do some measuring andd adjust accordingly.
I dont mean to steal your idea alex bud. Just looking on varoius mk4 forums they are audi 80/90 ones to get a cheap 15mm drop. And im prepared. To try it in hope of getting a longer lasting solution

[Error404]

Get it done mate, I've got too much on at the moment to try it.
I had looked at the powerflex black ones as if they are the same material as the black wishbone bushes they should be able to be turned on the lathe, thus be made to fit very neatly
Let us know how you get on with it

[afterburner]

People in Bulgaria have used MK4 golf top mounts in our cars for some time now. You shave the OD of the mounts so they fit the turrets and then you weld a Golf and an Audi upper spring seats together, because the Golf bearing needs a Golf spring seat so they can fit each other and the Golf spring is different to the Audi one, so that's why you use the lower part of an Audi spring seat. People are reporting that they have finally cured all the clunking in their cars.

I don't like the part with welding of the two spring seats together. Does anyone know a VW spring that uses the same seat as an Audi one, but has MK4 style bearings?

[Monkeymagic]

Only prob is kws top spring plate is a resin/ plastic composite. Ill get round to it at some point and report back. Its on my bucket list. I know its an exciting life i lead!
I dont think the mk4 top mount bearing is hugely different.
People on mk4 forum use audi ones so guess there is the clearance...

[afterburner]

The construction is very different between the two types of top mounts.

In the Audi ones the whole suspension lies on the bearing - shock and spring, that's why the bearing gives. In the mk4 bearings the shock is mounted directly to the top mount, because it goes through the moving part of the bearing. Only the spring pivots on the bearing.

This is superior to the Audi design, because all the big hits come from the shock, not from the spring, so in the mk4 top mount they are absorbed by the top mount, not the bearing.

In the mk4 design when you steer the shock strut stays stationary, only the MacPherson strut + spring turns. On top of that the mk4 bearing is bigger than the Audi one.

[Error404]

There is nothing different in how the MKIV platform mounts work, both mount in the same way. The loads are not separated between the spring and shock shaft - on both mounts the bearing takes the full loading of the sprung mass, as the bearing is seated between the spring seat and the top mount and the sprung mass rides on the spring. The shock shaft doesn't take any direct loading, only loading transferred through the spring seat - that's is how it dampens the spring oscillations.
The major difference is that the MK IV mounts are far more substantial with bigger bearings. Without measuring the MKIV bearings I can't see there is any need to modify the spring seat unless you are using OEM spring perches, in which case you might need to modify them to reduce the ride height to OEM level (MKIV spring perches are lower profile) and to increase the size of the bearing surface.

Except for the need to trim the OD to fit the strut tower, with coilover spring seats they should be a direct fit.

[afterburner]

The loads are not separated between the spring and shock shaft - on both mounts the bearing takes the full loading of the sprung mass, as the bearing is seated between the spring seat and the top mount and the sprung mass rides on the spring.

The sprung mass sits on the bearing - yes. But the shock shaft doesn't ride on the bearing. And if you hit a pothole or a curb (very quick compression of the suspension) the loads transmitted through the shock shaft are far greater than those transmitted through the spring (it's a spring, it compresses, on the other hand the shock stiffens up, because it can't handle the oil flowing through its shims). And those are the scenarios that stress the bearings. That's why the MK4 design is superior to the Audi design, not only are the bearings bigger, they also don't suffer those big hits.