mk1 front suspension travel.- UPDATED WITH PICS.

Cheers dub, thats useful info. i'll post up once i start messing about.,

 

Update

Got some made out of 25m thick MDF, cut outside to same size as my ali top mounts and inside to just smaller then the lip on top of the turret then filed it to a bevel for a nice tight fit against the lip once bolted down to help resist any lateral movement under load. Chiselling the spacer to fit the 3 raised ridges on the turret, Then drilled the turrets and spacers with extra holes, then painted with a few coats of blue garage door enamel to help protect them from any moisture! and finally secured with 9 x M8 12.9's with load speading washers under the turret. These bolt upto the threaded holes in the alloy topmount and then are also locknut secured on top.

9 bolts may be a bit overkill but better to on the cautious side. This has given me about 40mm more range on the damper. I won't know if it has made any/much difference till next trackday in Jan and by then it'd be quickracked and have different geo with my bottom ball joint spacers and rose jointed trackrod ends but a worthwhile experiment i think and it only owes me 25.





Edit.
i'm also going to look at fabricating another upper strut brace as i may be able to make one fit now the topmounts sit higher, the old one would'nt fit after i went to the ABF lump.

 

nice job there

 

Ian,

Interesting work .... any pictures from underneath the turret ?

How much castor ( 5` ? ) and camber do you intend ?

Cheers

 

Looking good!
Nothing wrong with 9 bolts and MDF

Very tempted to try spmething similar on my Cab which is alway running out of travel

 

Interesting to see what difference it makes Ian!

 

i'll take a pic when i get a chance.

I run about 2-2.5deg neg camber (but by using topmount to help achieve this you also affect SRA) and a bit more postive castor than factory setting (sorry don't know measurement) won't be as much as 5deg thou. More like 3 i'd guess, anybody know factory setting so we can work it out??

 

Nice 1 Ian. Your pics helped light up the old filament. Hope you get the results your after. Thanks.

Gurds

 

Thanks Ian,

My own Mk1 is set with 1.5` neg camber and 5` castor - for hills & sprints - castor setting gives better turn-in for the tight sections I believe. I also use eccentric, solid top mounts but located `under` the standard turret secured with three M8 capheads / nylocs - suspension is Leda and was specifically built for this set up.

Great to see your own developments !

 

I like the mod, but I'm jittery about the stress on the bolts when water is absorbed through use... What do you reckon?

 

i don't like the MDF, rubbish stuff

 

Water should not be absorbed as they have been well sealed, and i can't really see them overstressing the bolts even if it was.

If the idea works then i can always just use the wooden ones as a template to get some more expensive alloy one's turned up. but imho it's important that they fit very tight around the bevelled lip on top of the turret.

Now they are all made up i'm going to take them until after or possible during the next trackday as i want to see what difference the ball joint spacers and new rod ends make on their own 1st. I've learn from experience to only do 1 mod at a time.

 

In the geometry thread (can't rememebr were it was) you talked about bump steer, well in the 924 steering rack thread going on at the moment there is a link about it sharing internals with the mk1 golf & this is said at the bottom of the link:

"Bump Steer Kit
Jonathan O'Connor, a retired chassis engineer, has commented that the stock 924/944 suspension has a characteristically large amount of bump-steer. Bump steer is caused by the wheel and the end of the tie-rod moving in different arcs as the suspension is raised and lowered by the road surface. Ideally, they will move in the same arc, so that the wheel continues to point in the same direction. This is rarely possible, if at all, in a real sports car suspension, so that (all else being unchanged) as the wheel moves up and down relative to the vehicle, the wheel steers in and out a bit without the driver moving the steering wheel at all. This is most noticeable on bumpy roads, but also can have an effect on high-performance driving because of the change in stability and effective alignment (therefore handling balance) change as the car progresses through the corner.

This is only aggravated when the geometry is changed by such modifications as lowering the car. In order to allow this effect to be minimized, he has come up with a design modification which allows the vehicle owner to adjust and tune out the bump steer as desired. The following is his explanation of the procedure. The parts do require basic machining abilities to make, but are relatively simple. The tuning, however, is up to the driver - whatever feels comfortable! Jon's not giving away any secrets here:

Making a bump-steer kit for our cars is really easy...make a 6061 (aluminum) sleeve 1.125 OD (outer diameter)...about 6 inches long...drill and tap one end for rack thread (14mm I think) and other end for a 5/8 heim joint (aka rod end, available at most motorsports supply houses for $10-20))....then you drill out the taper in the steering arm of the upright (where the ball joint previously went through) to accomodate a 5/8 bolt....you can then shim the rod end up or down (using washers on the 5/8" bolt between the rod end and the steering arm) to tune the toe change out of the suspension...the tuning is a time consuming nuisance, but yields HUGE improvements in turn-in and mid-corner balance".

Is there anything in there that could help you or give you any more idea's mate?

 

Having lowered my Scirocco on coilovers the outer wishbone end points up,any ideas what effect this will have on the geometry?

 

It will adversly affect your rollcentres, do a couple of searches and theres a lot of info on here and on vortex.

Anyway as requested just a couple of pics to add. Now they're all made i've taken them off for the time being so i can test them independently of some other mods. I'll do it early next yr and If i remember i'll update again then!!

 

Ian... thanks

 

where did you get your solid top mounts from I V - mk1 16v ??

 

I was thinking about doing this to my Rocco so i could run the ride height that i wanted without the car wrecking bump steer. As I drive the car on roads at weekends however and couldnt find anyone who could guarentee me that their rod ends could deal with road use... Also there would be a need for a high angle rod end?

Has anyone done this and it remain in one piece? POST SOME PICS!!! As this seems like such a good idea.. Also i see al lot of the US A1 chassis track dayers run ball joint spacers so the steering arms run more level with the wishbone with the added advantage of the wishbone pointing in the right direction (from the centre of the car towards the road surface)..