DIY top mounts

Two things I don't like about those, one the entire force of the suspension movement is being put through three bolts, which look like only M6 or M8, two the same force of suspension movement is being put onto the weld! It would be much better to have the weld on the underside and keep the movable camber adjustment plate under the 6 bolt top plate. When looking at top mount ideas in the past. I would not go less than six bolts if the design is above the tunnel!

I may have an internal measurement for the maximum size the strengthening ring can be on the mk2. I shall have a look and dig it out.

 

I`m with Tom on this. I just don`t like those at all.

Most other topmounts have the adjusting plate UNDER the fixed plate so the weight of the car is pressure the moveable plate into the fixed one. With that, there is only a weld and 3 small bolts holding the weight of that corner !

 

Hmm, that is very weird. There is something weird and impossible with those.... Your right.

The sliding plate should fit underneath, and the bearing 'holder (better word?) looks like it has a flange that supports the weight, with the weld just holding it in place.

It looks like they are meant to be assembled as-per the bottom picture, with the bearing plate underneath. 6 bolt holes onto the shell (although maybe they could be bigger), and an extra plate that gets bolted under the turret like a massive washer...... BUT, the countersunk bolts would be pointing upwards? And the extra plate would get in the way of adjustment... and so would the turret...?
So yeah, it looks like they have been designed with the bearing plate ontop doesn't it. And the weld supporting the weight....? Surely not?

 

Another problem with fitting those to a mk2 golf, the washer plate that goes underneath sits into a circular recess, because it's not round it would not sit in it flush!

The other thing I don't like about these types of design is all you can adjust is camber, well camber can be adjusted easy by the suspension to upright nuts, as the normal way. What you want to get from a new top mount design is caster, and as much as possible! It really does not need to be adjustable either but the eccentric style mounts can offer adjustment and would be easy to make from plate steel.

 

It might be worth while someone speaking to Mart (hotgolf) on this as he will be able to give sme great input.

 

Any 'washer' ring you want to use must fit within the turrets circular shape with its lips (hard to identify in the pic), diemsions above and a pic of what it looks like once under seal has been removed from the edges.




and you can mount the topmount underneath using lip on the ring to ensure it is fully concentric before bolting it inplace.







Edit: drawing edited for correct dimensions! Which should read Version_1.1 21st October 2012

 

Speaking as someone who has used 'compbrake' type top mounts on nearly all my cars since about 1993 (concentric and eccentric) I can honestly say you'll struggle to find a better top mount than the Ground Controls.

I stumped up the cash and bought a pair of Mk1 specific Ground Controls and fitted them last week. Yes they are expensive, but if combrakes are worth 100 then GC's are easily worth the 320 they cost me..

Fitting was pretty easy, depending on how much of the GC's adjustability you wish to use you do need to clearance the turret, but it was nice that the mk1 specific version is machined away to clear the 3 bumps where the turret meets the inner wing so they can be left alone..

Adjusting camber and castor is a doddle, although I wanted them mostly to reduce my scrub radius..

Also bear in mind that GC's come with an upper spring plate mounted on a needle roller thrust bearing, a very nice touch.

Anyway.. back to the DIY top mounts..

 

I don't doubt it ^^

I wonder if we could incorporate some design features of those, without falling foul of any copyright issues. I couldn't justify the GC cost on a budget track car build, although on a full on race car, it's a smaller proportion of the overall cost.

I bought Jon Olds' Rally Mk1 Golf at the weekend. It uses old school Gp4 Escort mounts, which seem to do the job. Not 100% sure how much modification they got to fit in there, though.

 

It is tempting to just stump up the money for the GC ones, and save a load of hassle. Where did you get yours from Mickey, if you don't mind me asking?

If I adjusted my camper on the top mounts instead of the strut, I reckon my tyres would clear the spring platforms and I would not need the drop from the top mounts.....

 

kinda missing the point of the `diy` topmount idea though.

Whilst I don`t doubt they are good, I can`t justify that sort of money for a pair of top mounts.

 

But would GC do a bit of discount on a group buy?

 

Or can we figure out a design that incorporates the advantages of the GC mounts (without actually copying anyone's design) with ease of machining in a small batch, hopefully fitting more than one model with only minor mods to either the car or the mount - e.g. take the lip off the top of the strut tower.

Close up pictures of existing types would be very handy. I'll start with a bit of digging on google images.

 

Totally agree Nige.. just giving Ground Control a bit of backup, I've spent years looking at thier prices and saying they're not worth it, but now I'm converted and reckon they ARE worth the money.. IF you have the money.. otherwise back to the DIY...

 

Finally got Photobucket to upload my screen grabs... here are some more examples - all using slightly different methods.

Ground Control

rear view


A guy on the MIG welding forum - weld-in type. Looks like they only adjust in one direction, but weld-in is an interesting idea if you're sure you'll never want to convert back. Fewer bolts to vibrate loose.

He used cut-down compbrake plates.


Baker BM - Concentric holes probably mean a smaller range of adjustment, but an interesting idea.

 

If you want caster and camber adjustable top mounts, that fit to a mk1 and mk2 shell, then you really need the dimensions of the turret circumference for both inside and out, i have supplied mk2 inside and will supply out as well if you want. This will them present the criteria in which they have to be design, plus any other features such as mk1 strengthening ridges. I imagine having both caster and camber will compromise what your maximum of each can be.

 

Caster / Castor (?) angle is more important on a MK1 chassis I think, so I'd be after mounts have both types of adjustment.

I took a couple of pics and measurements tonight. Will post them up tomorrow.

 

This might sound stupid, but does it make any difference where the camber is adjusted from, ie, if it's adjusted at the bottom of the strut or at the top mount?

 

Not stupid at all.

The answer is yes, it makes a difference. Altering camber at the stut/upright doesn't change your scrub radius as the kingpin inclination stays the same. Adjusting at the top mount alters the kingpin inclination and therefore your scrub radius..

 

Sorry Mike, but the lower picture is NOT a rear view of Ground Controls.. its the top view of some other make..(or very early GC's)

 

Cool, just had a quick read up on scrub radius and kingpin, seems like having top mounts adjustable for both camber and castor would be better, if only to give more scope in having these figures set to the optimum.